lighting retrofit manual · utilities. among the most important are reduced electricity demand,...

Lighting Retrofit Manual

Technical Report

Lighting Retrofit ManualTR-107130-R1

Final Report, April 1998

Prepared forElectric Power Research Institute3412 Hillview AvenuePalo Alto, California 94304

EPRI Project ManagerJ. Kesselring

DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITIES

THIS REPORT WAS PREPARED BY THE ORGANIZATION(S) NAMED BELOW AS AN ACCOUNT OF WORK SPONSOREDOR COSPONSORED BY THE ELECTRIC POWER RESEARCH INSTITUTE, INC. (EPRI). NEITHER EPRI, ANY MEMBER OFEPRI, ANY COSPONSOR, THE ORGANIZATION(S) BELOW, NOR ANY PERSON ACTING ON BEHALF OF ANY OF THEM:

(A) MAKES ANY WARRANTY OR REPRESENTATION WHATSOEVER, EXPRESS OR IMPLIED, (I) WITH RESPECT TO THEUSE OF ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS REPORT,INCLUDING MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, OR (II) THAT SUCH USE DOES NOTINFRINGE ON OR INTERFERE WITH PRIVATELY OWNED RIGHTS, INCLUDING ANY PARTY'S INTELLECTUAL PROPERTY,OR (III) THAT THIS REPORT IS SUITABLE TO ANY PARTICULAR USER'S CIRCUMSTANCE; OR

(B) ASSUMES RESPONSIBILITY FOR ANY DAMAGES OR OTHER LIABILITY WHATSOEVER (INCLUDING ANYCONSEQUENTIAL DAMAGES, EVEN IF EPRI OR ANY EPRI REPRESENTATIVE HAS BEEN ADVISED OF THE POSSIBILITYOF SUCH DAMAGES) RESULTING FROM YOUR SELECTION OR USE OF THIS REPORT OR ANY INFORMATION,APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS REPORT.

ORGANIZATION(S) THAT PREPARED THIS REPORT

ELEY ASSOCIATES

ORDERING INFORMATION

Requests for copies of this report should be directed to the EPRI Distribution Center, 207 CogginsDrive, P.O. Box 23205, Pleasant Hill, CA 94523, (510) 934-4212. Electric Power Research Institute andEPRI are registered service marks of Electric Power Research Institute, Inc. EPRI.POWERING PROGRESS is aservice mark of Electric Power Research Institute, Inc.

Copyright © 1998 Electric Power Research Institute, Inc. All rights reserved.

iii

REPORT SUMMARY

Lighting retrofits offer many benefits for building owners, building users, and electricutilities. Among the most important are reduced electricity demand, significant energysavings, and lower building operating costs. This handbook provides a resource forutility representatives that explains the technical and financial considerations oflighting retrofits, describes the most popular retrofit possibilities, and illustrates soundretrofit decision making.

BackgroundLighting accounts for 30-35% of electricity use in commercial buildings. High efficiencylighting retrofits can cost-effectively save from 30-50% of this energy while enhancingthe visual environment and improving lighting quality. Most lighting retrofits pay forthemselves through energy savings in less than five years; indeed, in many cases,simple payback occurs in under three years. When occupant satisfaction and workerproductivity are factored into the economic analysis, lighting improvements produceimmediate benefits.

ObjectiveTo develop a handbook that will help utility representatives provide building ownerswith concise, accurate, up-to-date information on lighting retrofits using energy-efficient technologies.

ApproachLighting professionals developed the handbook based on their collective experience inperforming lighting audits for utility programs, energy service companies, buildingowners, and design professionals. EPRI personnel and other lighting industryprofessionals reviewed the handbook for accuracy and relevance.

ResultsThis handbook—which may serve as a training manual or a reference—providesreadily accessible information on the following key topics:

x The importance of lighting retrofits, including a summary of when retrofits makesense as well as the role of the utility in the retrofit process

x The lighting retrofit process, with step-by-step examples and illustrations

iv

x The basic technologies used to improve lighting systems in existing buildings, withemphasis on lamp/ballast, luminaire, and control technologies

x Retrofit opportunities for commercial, industrial, and outdoor lighting system types

The handbook includes a quick reference checklist of all lighting retrofit opportunitiesfor use by lighting auditors. Nine appendices provide information on power quality aswell as how to calculate illumination levels, measure illumination levels in the field,perform cost-effectiveness calculations, and collect field data. The appendices alsosummarize other EPRI tools and publications and provide a glossary of terms.

EPRI PerspectiveRetrofitting existing buildings with more efficient lighting devices is both an easy andcost-effective way to reduce building energy use and operating expenses. Lightingretrofits make the most sense in the following circumstances: excessive illuminance ofall or portions of the building, use of lighting equipment over 10 years old, lamps andluminaires that have been poorly maintained, operation of lighting for more hours thanneeded, high electricity and/or demand charges, and suboptimal lighting conditions.Among the most significant and immediate benefits of retrofitting outdated lightingsystems are an improved luminous environment, reduced lighting energy and buildingoperating expenses, and decreased lighting maintenance. These benefits can lead toincreased worker productivity, greater economic competitiveness, and cleaner air.Although other building system retrofits—including premium efficiency motors,variable-speed drives, and improved building automation and control—are effectiveand desirable, lighting retrofits generally require lower capital investment, have ahigher return on investment, and are more appealing to building owners.

This handbook is one of a series of EPRI lighting documents designed to assist utilityrepresentatives. The Lighting Fundamentals Handbook (TR-101710) provides basicinformation on vision, physics, electrical equipment, and design practice. EPRI'sAdvanced Lighting Guidelines (TR-101022, R1) offer a more comprehensiveunderstanding of modern lighting equipment and specific application guidelines on theuse of energy-efficient sources, luminaires, and control equipment. Finally, LightPAD2.0 serves as a portable audit and design tool for evaluating retrofit lighting options.

TR-107130-R1

Interest Categories Key WordsBuilding systems and analysis tools LightingLighting Control systemsEnergy management and controls, Luminairesoffice automation Energy efficiency

Daylighting

v

ABSTRACT

This handbook is a general reference for utility representatives that explains thetechnical and financial considerations of lighting retrofits, describes the most commonretrofit technologies and illustrates sound retrofit decision making. The handbook isorganized in five chapters. Chapter 1 is an overview of the issues and benefits relatedto lighting retrofits. Chapter 2 presents details on the process of evaluating a buildingto determine if lighting retrofits make sense. Chapter 3 covers the basic lighting retrofittechnologies including lamp/ballast technologies, luminaire retrofit opportunities, andcontrol strategies. Chapter 4 summarizes lighting retrofit opportunities for variouslighting system types including general commercial, industrial and outdoor systems.Chapter 5 is a quick look-up matrix retrofit opportunities which summarizes the moredetailed information in Chapters 3 and 4. The handbook is supported by nineappendices with useful reference information on how to calculate illumination levels,measure illumination levels in the field, perform cost-effectiveness calculations, andcollect data in the field. Other appendices address issues related to power quality,summarize other EPRI tools and publications, and define terms and concepts in aglossary. The handbook may be used as a training manual or as a reference.

vii

ACKNOWLEDGMENTS

This handbook was written by Charles Eley of Eley Associates with valuablecontributions from James R. Benya of Pacific Lightworks. Miriam Phillips wasresponsible for copy editing and Irene Chan for graphic design. A thorough technicalreview was provided by Don Aumann and Larry Ayers of Bevilacqua-Knight, Inc. KarlJohnson of EPRI was the project manager.

ix

CONTENTS

1 OVERVIEW............................................................................................................... 1-1

Introduction .............................................................................................................. 1-1

Significance of Lighting Retrofits .............................................................................. 1-2

Benefits of Retrofitting.............................................................................................. 1-3

Lighting Quality ..................................................................................................... 1-3

Reduced Energy Costs......................................................................................... 1-3

Reduced Lighting Maintenance ............................................................................ 1-5

Capital Availability................................................................................................. 1-5

Economic Competitiveness .................................................................................. 1-5

Cleaner Air............................................................................................................ 1-5

Good Public Relations .......................................................................................... 1-6

Improved Lighting and Productivity....................................................................... 1-6

When Lighting Retrofits Make Sense....................................................................... 1-8

Excessive Illuminance .......................................................................................... 1-8

Inefficient Technology........................................................................................... 1-9

Poor Maintenance................................................................................................. 1-9

Long Hours of Operation .................................................................................... 1-10

High Electricity and/or Demand Charges............................................................ 1-11

Suboptimal Lighting Conditions (Deferred Capital Re-Investment) .................... 1-11

The Role of the Utility............................................................................................. 1-11

Barriers ............................................................................................................... 1-11

Demand-Side Management (DSM) Programs.................................................... 1-12

The Retrofit Process .............................................................................................. 1-13

2 THE LIGHTING RETROFIT PROCESS ................................................................... 2-1

Overview .................................................................................................................. 2-1

Diagram of Process .............................................................................................. 2-1

Participation by the Utility Representative ............................................................ 2-2

x

The Players........................................................................................................... 2-4

Information Resources.......................................................................................... 2-5

Qualification Phase .................................................................................................. 2-6

Data Collection Phase.............................................................................................. 2-9

Plan Survey .......................................................................................................... 2-9

Interviews with Building Operators ..................................................................... 2-11

Lighting Survey (Audit) ....................................................................................... 2-12

Engineering Phase................................................................................................. 2-16

Lighting Quantity and Quality Issues .................................................................. 2-16

Lighting Schedules ............................................................................................. 2-22

Confirming Assumptions..................................................................................... 2-32

Retrofit Approaches—Relamping vs. Redesign.................................................. 2-33

Estimating Energy Cost Savings......................................................................... 2-34

Replacement and Maintenance Costs................................................................ 2-40

Economic Analysis.............................................................................................. 2-41

Construction and Commissioning Phase ............................................................... 2-41

Bid Documents ................................................................................................... 2-41

Bidding and/or Negotiation ................................................................................. 2-42

Construction........................................................................................................ 2-42

Lamp and Ballast Disposal ................................................................................. 2-42

Asbestos ............................................................................................................. 2-43

Commissioning ................................................................................................... 2-43

Verification and Measurement ............................................................................ 2-43

Ongoing Maintenance............................................................................................ 2-45

3 RETROFIT TECHNOLOGIES .................................................................................. 3-1

Lamp/Ballast Technologies ...................................................................................... 3-1

Relamping Retrofit Opportunities.......................................................................... 3-1

Lamp Performance Measures .............................................................................. 3-3

Lamp Efficiency and Energy Legislation............................................................... 3-8

Tungsten Halogen Lamps................................................................................... 3-12

Compact Fluorescent Lamps.............................................................................. 3-13

Full-Size Fluorescent Lamps .............................................................................. 3-16

High-Intensity Discharge Lamps......................................................................... 3-22

Luminaire Retrofit Technologies ............................................................................ 3-42

Optical Reflectors ............................................................................................... 3-43

xi

Lenses ................................................................................................................ 3-52

Control Technologies ............................................................................................. 3-54

Retrofitting Occupancy Sensors ......................................................................... 3-54

Dimming Controls ............................................................................................... 3-57

Timers and Time Clocks ..................................................................................... 3-60

Powerline Carrier Controls.................................................................................. 3-62

Photocells ........................................................................................................... 3-63

Photosensors...................................................................................................... 3-63

Latching Switches............................................................................................... 3-64

4 LIGHTING SYSTEM TYPES .................................................................................... 4-1

General Commercial ................................................................................................ 4-1

General Commercial Lighting Systems ................................................................ 4-1

Fluorescent Troffers ............................................................................................. 4-2

Incandescent Downlights...................................................................................... 4-7

Fluorescent (non-troffers) ................................................................................... 4-12

HID Lighting Systems ......................................................................................... 4-16

Commercial Decorative Lighting......................................................................... 4-19

Commercial Utility Lighting ................................................................................. 4-23

Exit Signs and Other Self-Illuminated Signs ....................................................... 4-25

Track Lighting ..................................................................................................... 4-26

Industrial................................................................................................................. 4-28

Industrial Fluorescent ......................................................................................... 4-28

Watertight Fluorescent........................................................................................ 4-30

HID High Bay Area and Aisle.............................................................................. 4-31

HID Low Bay Area and Aisle............................................................................... 4-32

HID Vaportight .................................................................................................... 4-33

Special Purposes/Environments......................................................................... 4-34

Outdoor .................................................................................................................. 4-34

Street and Road Lights ....................................................................................... 4-34

Floodlights and Billboard Lights.......................................................................... 4-35

Wallpacks ........................................................................................................... 4-36

Bollards............................................................................................................... 4-36

Parking Garage Fixtures..................................................................................... 4-37

Step Lights.......................................................................................................... 4-37

Landscape Lights................................................................................................ 4-38

xii

5 SUMMARY OF RETROFIT OPPORTUNITIES ........................................................ 5-1

Commercial .............................................................................................................. 5-1

Industrial................................................................................................................... 5-6

Outdoor .................................................................................................................... 5-9

A GLOSSARY OF TERMS..........................................................................................A-1

B BIBLIOGRAPHY......................................................................................................B-1

EPRI Reports and Fact Sheets ................................................................................ B-1

Lighting Bulletins, Handbooks, and Reports......................................................... B-1

Applications .......................................................................................................... B-2

Videotapes............................................................................................................ B-2

Brochures ............................................................................................................. B-2

Fact Sheets........................................................................................................... B-2

Software................................................................................................................ B-2

IESNA Publications: ................................................................................................. B-3

General ................................................................................................................. B-3

Recommended Practices...................................................................................... B-3

Light Energy Management.................................................................................... B-3

Other Publications:................................................................................................... B-3

Associations, Societies, and Institutes ..................................................................... B-5

Ordering Information ................................................................................................ B-7

C EPRI’S LIGHTING ANALYSIS TOOLBOX..............................................................C-1

Lighting Audit Software: LightPAD 2.0 .....................................................................C-1

Daylighting Analysis: Building Energy Estimation Module (BEEM) ..........................C-1

Lighting and Other Building Systems: COMTECH ...................................................C-2

Lighting Evaluation System (LES)............................................................................C-2

Post-Retrofit Calibration and Commissioning: Lighting Diagnostics andCommissioning System (LDCS)...............................................................................C-2

D CALCULATING ILLUMINATION LEVELS..............................................................D-1

The Lumen Method..................................................................................................D-1

Coefficient of Utilization (CU)................................................................................D-2

Room Cavity Ratio................................................................................................D-3

Light Loss Factor ..................................................................................................D-3

Point Source Calculations ........................................................................................D-5

xiii

E MEASURING ILLUMINATION LEVELS .................................................................. E-1

As-Is Measurements vs. Initial Lumen Measurements ............................................ E-1

Photometers and Calibration.................................................................................... E-2

Measurement Procedures........................................................................................ E-3

Measurements in Daylighted Areas...................................................................... E-4

Task Lighting ........................................................................................................ E-4

F CALCULATING COST-EFFECTIVENESS .............................................................. F-1

Introduction .............................................................................................................. F-1

Payback Period..................................................................................................... F-1

Net Present Value (Life-Cycle Cost) ..................................................................... F-1

Benefit-to-Cost Ratio ............................................................................................ F-5

Internal Rate of Return ......................................................................................... F-5

Annualized Cost.................................................................................................... F-5

Other Issues............................................................................................................. F-6

Inflation and Energy Cost Escalation Rates.......................................................... F-6

Tax Considerations............................................................................................... F-6

G POWER QUALITY...................................................................................................G-1

Supply Voltage .........................................................................................................G-1

Voltage Regulation ...............................................................................................G-1

Voltage Transients................................................................................................G-2

Voltage Surges and Sags .....................................................................................G-2

Voltage Interruption ..............................................................................................G-2

Power Factor............................................................................................................G-3

Harmonic Distortion..................................................................................................G-3

H LIGHTING SURVEY FORMS...................................................................................H-1

Suggested Data Structure ....................................................................................H-1

I LIGHTING EDUCATION AND LABORATORY FACILITIES..................................... I-1

Utility-operated Centers ............................................................................................ I-1

Lamp Company Centers ........................................................................................... I-4

1-1

1 OVERVIEW

Introduction

Building owners frequently turn to utility representatives for information and guidanceon energy-efficiency issues, including lighting equipment retrofits. This handbook is aresource for utility representatives that explains the technical and financialconsiderations of lighting retrofits, describes most of the common and/or popularretrofit possibilities, and illustrates sound retrofit decision making. The book addressesprimarily one-for-one retrofits, but does not address new fixture replacements.

This handbook is one of a series of lighting documents and resources produced byEPRI. Others include the Lighting Fundamentals Handbook, TR-101710, which providesbasic introductory information on vision, lighting physics, electrical equipment anddesign practice; the Advanced Lighting Guidelines, TR-101022, R1, which offers a morecomprehensive understanding of modern lighting equipment, containing specificapplication guidelines for the use of energy-efficient sources, luminaires and controlequipment; and LightPAD 2.0, a portable audit and design tool for evaluating retrofitlighting options. Appendices B and C list publications and software available fromEPRI.

This handbook is organized into five chapters.

x Chapter 1 provides information on the importance of lighting in building energyuse and the magnitude of opportunities to save energy; summarizes the benefits oflighting retrofits and when they make sense; discusses the role of the electric utility;and reviews the lighting retrofit process.

x Chapter 2 presents details on each step of the lighting retrofit process; discussesshort-term monitoring and when it should be used; and contains examples andillustrations of each step.

x Chapter 3 presents information on the basic technologies used to improve lightingsystems in existing buildings. The chapter is organized in three sections:lamp/ballast technologies, luminaire technologies, and control technologies.

x Chapter 4 describes each of the important lighting system types (commercial,industrial, and outdoor) and addresses the retrofit opportunities for each type. Bothgeneral information and retrofit opportunities are presented for each lightingsystem type.

Overview

1-2

x Chapter 5 summarizes all lighting retrofit opportunities presented in the twoprevious chapters into a quick reference or checklist for use by lighting auditors.

In addition to the five main chapters, the handbook has nine appendices that areprovided for reference.

x Appendix A: Glossary of Terms. A definition of terms used in the handbook and inthe lighting profession.

x Appendix B: Bibliography. A listing of publications from EPRI and others that willprovide additional information on lighting retrofits.

x Appendix C: EPRI’s Lighting Analysis Toolbox. A summary of EPRI software forassisting in the lighting retrofit process.

x Appendix D: Calculating Illumination Levels. A brief explanation of the lumenmethod of calculating illumination levels in spaces.

x Appendix E: Measuring Illumination Levels. Details on how to measure lightinglevels in spaces, including calibration of instruments and accounting for dirtyluminaires and/or aged lamps.

x Appendix F: Calculating Cost-Effectiveness. Definitions of simple payback, life-cycle cost, net present value and other terms used in evaluating the cost-effectiveness of lighting retrofit opportunities.

x Appendix G: Power Quality. Information on power quality issues related tolighting retrofits.

x Appendix H: Lighting Survey Forms. Recommended data organization and samplesurvey forms for making audits.

x Appendix I: Lighting Education and Laboratory Facilities. List of education andlaboratory facilities for studying lighting technologies.

Significance of Lighting Retrofits

Energy-efficient lighting retrofits make good economic sense for most commercialbuildings. Replacing aged lighting components with advanced energy-efficientcomponents can save as much as 40% of a building's lighting energy costs whilemaintaining or enhancing the quality of the visual environment in the modernworkplace. Most lighting retrofits pay for themselves through energy savings in lessthan five years; indeed, in many cases, simple payback occurs in under three years.When occupant satisfaction and worker productivity are factored into the economicanalysis, lighting improvements produce immediate benefits.

Lighting represents a major end use in commercial buildings, accounting forapproximately 30–35% of commercial sector electricity consumption. Lighting retrofits

Overview

1-3

can cost-effectively save from 30–50% of this energy. American business is underconstant pressure from abroad to increase productivity and cut costs.

Lighting improvements are a cost-effective investment that reduces building operatingcosts and can improve worker productivity.

Benefits of Retrofitting

Lighting retrofits have many benefits for the building owner, the building users, andthe electric utility. The most important and direct benefits are reduced electricitydemand, energy savings, and lower building operating costs. Less quantifiable benefits,such as improved lighting quality and possible productivity boosts, may be even moreimportant.

Figure 1-1 Lighting’s Strategic Importance

Lighting Quality

Probably the most important benefit of a lighting retrofit is an improved luminousenvironment. In addition to saving energy, lighting retrofits can correct pre-existinglighting problems by providing adequate illumination, reducing flicker, andcontrolling glare.

Reduced Energy Costs

The most obvious and immediate benefit of retrofitting an outdated lighting system isreduced lighting energy and related operating expenses. In fact, this is often the onlybenefit considered in assessing the cost-effectiveness of lighting retrofits. Lighting

Overview

1-4

retrofits reduce both electricity use and demand. The savings include direct reductionsin lighting power and hours of lighting operation as well as indirect air conditioningenergy savings (there is less heat to remove from the building). A retrofit canoccasionally achieve a 50% reduction in the lighting share of the electric bill. The totalelectric bill for a typical office building can often be reduced by 20–25%.

Example 1-1How Much Energy Can Be Saved?

U. S. commercial buildings contain approximately 300 million fluorescent troffers and400 million fluorescent strip lights and industrial luminaires. These fixtures mostlyemploy four-foot rapid-start lamps. It is a reasonable assumption that some 80–90% ofthese luminaires are equipped with relatively antiquated T-12 lamps and magneticballasts. If these fixtures were retrofit with electronically ballasted T-8 lamps, inputpower would be reduced by an average of about 12 watts per lamp.1 This would reducepeak demand by over 20,000 megawatts, save 60 billion kilowatt hours annually, andreduce operating costs by $4.8 billion per year. This impact would result from onesimple lighting retrofit. Other retrofits, such as replacing incandescent lamps withcompact fluorescent lamps, could also result in dramatic savings.

Retrofitting existing buildings with more efficient lighting devices is both an easy andcost-effective way to reduce building energy use and operating expenses. Althoughother building system retrofits, including premium efficiency motors, variable-speeddrives, and improved building automation and control, are effective and desirable,lighting retrofits generally have a higher return on investment and are more appealingto building owners. In addition, well-designed lighting retrofits are aesthetic and canimprove worker productivity, while most other types of improvements are less visibleto the building users.

1 The range is 6–16 watts of savings per lamp.

Overview

1-5

Reduced Lighting Maintenance

Most energy-efficient lighting retrofits also reduce maintenance costs. In many existingbuildings, lighting system maintenance occurs only when there are equipment failuressuch as lamp and/or ballast burnouts. Routine group relamping and fixture cleaningare the exception rather than the rule. Since lighting retrofit programs usually involvesignificant equipment replacements, they are often overcoming 10 years or more ofneglect and offer an opportunity to initiate new maintenance procedures that canreduce maintenance costs in the long term while rejuvenating the building's appearanceand sense of brightness. Future maintenance costs associated with old ballasts can beeliminated, and lamps will not need to be replaced as often since energy-efficientproducts almost always have longer lives. This is especially true when incandescentlamps are replaced with longer-lived compact fluorescent lamps. Retrofit programsprovide a windfall of savings in the first year by installing all new lamps and canprovide the economic benefit of deferring ballast replacement by 20 years.

Capital Availability

Projected energy savings from lighting retrofits can be used as “equity” to finance theimprovements. This capital is available through utility programs as well as energyservice companies (ESCOs) that will finance retrofits through future energy savings.Often it is possible to package improvements so that older building equipment needingreplacement can be included as part of the retrofit program.

Economic Competitiveness

Lighting retrofits enable companies to reduce costs and become more competitive in theworld economy. This can result in greater economic growth for regions that activelypromote lighting retrofits.

Cleaner Air

A great deal of electricity is produced through gas-, oil- or coal-fired generation plants,and the combustion process adds pollutants to the atmosphere. These pollutantscontribute to global warming, acid rain, and other environmental problems. Energysavings through lighting retrofits can significantly reduce these emissions. TheEnvironmental Protection Agency (EPA) has estimated the emission reductionsassociated with electricity energy savings (see Table 1-1).

Overview

1-6

Example 1-2Reducing Air Pollution

The 60 billion kilowatt-hours of annual energy savings in Example 1-1 would eliminate96 billion pounds of carbon dioxide emissions, 320 million kilograms of sulfur dioxideemissions, and 170 million kilograms of nitrogen oxide emissions.

Good Public Relations

Not only do lighting retrofits save energy, operating costs, and air pollution, they canhelp foster a more positive image for customers that implement the improvements andthe utilities that promote the improvements. Participation in the EnvironmentalProtection Agency's "Green Lights" program is based in large part on EPA’s success inpromoting a positive image for participating companies.

Improved Lighting and Productivity

It is very difficult, some would say impossible, to document and quantify therelationship between lighting retrofits and worker productivity. Few persons wouldargue, however, that improving the visual environment hurts productivity. On thecontrary, there is little doubt that workers will be more productive if glare is removedfrom computer screens, the electric light provides better color rendering, and flicker iseliminated. The difficult thing is assigning a monetary value to these benefits.

Figure 1-2 The Cost of Doing Business2

Overview

1-7

Table 1-1Pollution Reductions Associated with Electricity Energy Savings

Emission Reductions per kWh of Electricity Savings

Carbon DioxideReduction (lb)

Sulfur DioxideReduction (g)

Nitrogen Oxide (g)

By Generating Source

Gas 1 1.4 0.0 2.4

Oil 1 1.9 3.7 1.5

Coal 1 2.4 9.0 4.4

Averages by Region

Region 1 (CT, MA, ME, NH, RI, VT) 2 1.1 4.0 1.4

Region 2 (NJ, NY, PR, VI) 2 1.1 3.4 1.3

Region 3 (DC, DE, MD, PA, VA, WV) 2 1.6 8.2 2.6

Region 4 (AL, FL, GA, KY, MS, NC, SC, TN) 2 1.5 6.9 2.5

Region 5 (IL, IN, MI, MN, OH, WI) 2 1.8 10.4 3.5

Region 6 (AR, LA, NM, OK, TX) 2 1.7 2.2 2.5

Region 7 (CO, MT, ND, SD, UT, WY) 2 2.0 8.5 3.9

Region 8 (CO, MT, ND, SD, UT, WY) 2 2.2 3.3 3.2

Region 9 (AZ, CA, HI, NV) 2 1.0 1.1 1.5

Region 10 (AK, ID, OR, WA) 2 0.1 0.5 0.3

National Average 3 1.6 5.3 2.8

Notes

1. Source: R. Arnold Tucker, Microcomputer Software for Evaluating Lighting Operations, Energy Engineering, Vol. 90,No.1, 1993.

2. Source: U. S. Environmental Protection Agency, Green Lights Lighting Upgrade Manual, September 30, 1994.

3. Weighted average based on 57% coal fired, 5.5% oil fired and 9.4% gas fired.

Salary expenses dominate the cost of doing business, and only the slightestimprovement can be quite significant. Based on a 1990 national survey of large officebuildings, salary costs represented $131 per square foot, almost 85 times greater thanelectricity costs which are estimated to be about $1.53 per square foot (see Figure Error!Reference source not found.). A productivity increase of as little as 1% would justabout equal the entire annual electric bill.

Another way to illustrate the impact that lighting retrofits can have on workerproductivity is to cite some examples3.

x Pennsylvania Power & Light retrofitted the lighting system in a drafting room. Theretrofit cost was $8,362 and energy cost savings were $2,035 per year. In addition,absenteeism went down by 25% and the rate at which drawings were producedwent up 13.2%.

3 Ibid.

Overview

1-8

x Hyde Tools retrofitted the lighting system in one of its facilities at a cost of $98,000.In addition to energy cost savings of $48,000 per year, the company estimates that itsproduct worth increased $25,000 per year (due to productivity increases).

x Boeing Aircraft company retrofitted the lighting system in one of its manufacturingplants. Not only did the company save 90% of the electricity costs for lighting, itexperienced a 20% improvement in detecting imperfections.

x The U. S. Post Office in Reno, Nevada, installed a new ceiling system and retrofitthe lighting system in its postal processing facility. As a result it saves $22,400 peryear in energy costs and enjoys a 6% increase in the processing rate.

These examples all represent cases where the lighting retrofit improvements werejustified on the energy savings alone. The increases in productivity were an unexpectedadditional benefit. In each of these cases, there was no change in management style.Productivity was monitored routinely before the retrofit and continued to be monitoredin the same manner after the retrofit.

When Lighting Retrofits Make Sense

Lighting retrofits make sense any time lighting energy can be saved cost-effectively.This usually results when one or more of the following conditions exist in a building.

x Excessive Illuminance. A majority of spaces in the building are overlighted.

x Inefficient Technology. The lighting equipment is more than 10 years old.

x Poor Maintenance. Lamps are beyond their useful life and luminaires are poorlymaintained.

x Excessive Hours of Lighting Operation. Lighting is operated for more hours thanneeded.

x High Electricity and/or Demand Charges. More money is saved per kWh or kWreduction.

x Suboptimal Lighting Conditions. There are inadequate or poorly maintained lightingsystems that need to be modified anyway.

Excessive Illuminance

Buildings that are overlighted are always candidates for lighting retrofits. Mostunmodified buildings constructed before 1980 are likely to be overlighted for severalreasons.

x The wide acceptance of fluorescent lighting during the 1950s and 1960s made ittechnically possible to design lighting systems with high illumination levels.Customarily, excessive lighting was installed in the belief that more was better.

Overview

1-9

x Before the 1980s, the lighting levels recommended by the IESNA and otherconstruction guidelines were considerably higher than today’s standards.

x Visual tasks have changed. Since the early 1990s, many workers spend much oftheir time in front of a computer screen, and paper tasks have improved greatly dueto laser printers and xerography.

To examine whether a space is correctly illuminated or whether it is over—orunderlighted, compare the actual light levels in the room (obtained by measurement orcalculation) to the recommendations of the IESNA (Illuminating Engineering Society ofNorth America). Procedures for determining light levels and comparing them to theIESNA recommendations are summarized on page 2-10.

Inefficient Technology

The efficiency of lighting equipment has markedly improved since the energy crisis ofthe early 1970s. Much of this improvement has been accompanied by improvements inlighting quality as well. For instance, electronic ballasts eliminate fluorescent flickerand T-8 lamps have better color rendering. However, older inefficient equipment is stillin common use, and its replacement is a primary strategy in lighting retrofits. Table 1-2presents examples of inefficient technologies and their possible efficient replacements.

Table 1-2Retrofit Technologies for Lighting Efficiency

Existing Technology Energy-Efficient Replacement

Standard fluorescent magnetic ballasts

“Energy saving” fluorescent ballasts

Standard fluorescent lamps

F40T12 (F30T12, F20T12)

F96T12

Other

Incandescent “A” lamps

Incandescent “PAR” and “R” lamps

Mercury vapor lamps

Metal halide lamps

Metal halide electromagnetic ballasts

Wall switches

Energy saving or heater cutout electromagnetic ballasts

Electronic ballasts

T-8 or T-5 lamps (rare earth phosphor)

FO32T8 (F25T8, F17T8)

F96T8, F96T8/HO

T-8 or T-5 lamps of other types

Compact fluorescent lamps

Halogen and halogen IR lamps

High-pressure sodium and metal halide lamps

Reduced wattage metal halide lamps

Electronic ballasts

Motion sensor switches

Poor Maintenance

Overview

1-10

Poor or infrequent maintenance results in dust and dirt accumulation on lamps andfixtures. This interferes with light delivery and reduces the efficiency of luminaires.Poor maintenance also results in the use of lamps that are beyond their rated lives. Oldlamps use the same power as new ones but produce significantly less light. Neither ofthese conditions actually increase energy use (except in the case of low pressure sodiumlamps), but they can result in light levels that are well below those the system wasdesigned to deliver. This can be a significant problem in an "aggressive" retrofit inwhich the design light level is very close to the IES recommended maintained level. Insuch a design, more frequent and thorough maintenance is necessary to ensure thatmaintained light levels remain at or above IES recommended levels.

Long Hours of Operation

Even a small improvement in lighting efficiency (power reduction) can save aconsiderable amount of energy when the lighting system is operated almostcontinuously. Long hours of lighting operation typical of hospitals, police stations,correctional facilities, etc. make most retrofits easy to justify.

Long hours of operation may also point to the need for automatic lighting controls suchas time clocks, occupancy sensors, and other devices. One of the most needless—andcommon—wastes of energy is the operation of lights in unoccupied spaces. The savingscan be enormous. While efficient equipment can reduce lighting energy use by as muchas 50%, turning lights off saves 100%. Consider the following control opportunitieswhen planning lighting retrofit projects.

x When activities conform to a regular schedule, time clocks or an energymanagement system can be used to schedule lighting.

x Spaces with irregular use can benefit from the use of occupancy sensors. Suchcontrols are available to replace wall switches in small areas.

x In large areas, occupant sensors can be installed on the ceiling. Some controlsincorporate photo sensors for daylighting control as well. Many occupant sensorscombine both infrared and ultrasonic detection methods to prevent false readings inrooms with sedentary occupants.

x Spaces with sporadic occupancy can be equipped with interval timers that turn offthe lights after a specified time period. These timed switches, available in bothmechanical and electronic versions, generally replace existing toggle switches.

Regardless of the control devices used, information programs for the building users areimportant. Many people believe that it wastes energy to turn off lights for short periodsof time. The truth is that fluorescent lights and incandescent lamps should always beturned off when not necessary. Signs located on doors and near switches can remindoccupants to turn off lights when they leave a room.

Overview

1-11

High Electricity and/or Demand Charges

When rates are high, it is easier to justify investments in efficient lighting. While thecost of the retrofit remains the same, the energy cost savings are much greater. Lightingretrofits that would otherwise be marginal are likely to be cost-effective.

Because utilities must base their power delivery potential on anticipated peak use, theyattempt to reduce the magnitude of those peaks through demand charges anddifferential billing rates, in which the price charged for electricity is substantiallyhigher during peak-demand periods than during off-peak hours. This peak period isgenerally during the afternoon, when the use of office equipment and air conditioningis at its highest. Strategies that minimize electric lighting during peak hours—such asdaylighting, task lighting, and careful controls—will return proportionally greatersavings than those that reduce electricity use during off hours.

Suboptimal Lighting Conditions (Deferred Capital Re-Investment)

Although the focus of this handbook is on retrofitting lighting systems to save energy,it is important not to lose sight of the connection between a high-quality visualenvironment and the increased well-being and productivity of the occupants. Buildingsthat have inadequate lighting systems probably already need improvements. Throughthe use of efficient lighting technologies, lighting energy use can remain constant oreven fall as a building’s lighting systems are renovated. Capital re-investment may beminimized through incentives or other benefits of new lighting systems.

The Role of the Utility

In spite of the enormous benefits and the availability of energy-efficient lightingtechnologies, significant barriers deter building operators from embracing newertechnologies. Often, utility customers mistrust newer products, due to confusion aboutthe technology, codes, standards, and the risk of construction disruptions to ongoingbusiness operations. Utility demand-side management (DSM) programs havedemonstrated that customers will move toward more energy-efficient lightingsolutions.

Barriers

Resistance to lighting improvements occurs in response to any or all of the followingfactors:

x perceived high initial costs of lighting improvements

x no perceived need to save energy

Overview

1-12

x lack of understanding about the advantages of better lighting

x mistrust about the reliability of newer technologies

x confusion over a bewildering assortment of products

x confusion and mistrust about unsubstantiated claims of energy savings made bysome lighting equipment manufacturers

x concern about disruptions to business during construction

For the most part, these perceptions are caused by simple ignorance, which the utilitycan overcome through intelligent marketing techniques targeted at increasing customerawareness about improved lighting products and energy efficiency. Resistance tochange will evaporate with the realization that lighting retrofits mean reducedoperating costs, a greater ability to compete economically, environmental benefits, andimproved worker productivity.

Demand-Side Management (DSM) Programs

Utilities have effectively used DSM programs to manage economic growth with fewereconomic and environmental costs than would result by building new power plants. Inaddition, an environmentally-conscious public prefers the DSM alternative overconstruction of new power plants.

DSM programs require that utilities invest capital in human resources, equipment, andprograms that will influence the consumer's use of energy. Successful programs reducedemand and energy use at a cost less than that needed to construct new generationcapability. “Least-cost planning” is a term which applies to the process of carefullyevaluating energy savings opportunities along side opportunities to increase generatingcapacity. Lighting retrofits usually surface as one of the most cost-effective ways toreduce electricity demand and energy use. Lighting retrofits can represent up to 80%(in some cases) of utility DSM investments4. In addition, lighting improvements areusually the most noticeable efficiency improvements in buildings, and they have atremendous visual impact on building occupants and visitors.

Utility DSM programs can employ a number of strategies to promote investment inenergy-efficient lighting. These include providing general customer service; directlyparticipating through subsidiary energy service companies (ESCOs); performinglighting audits for customers and making recommendations; subsidizing the cost oflighting improvements through rebates, grants and financing; helping owners anddesigners to select efficient lighting equipment and to assess lighting options;

4 Frey, Donald J., Stuart S. Waterbury, Karl Johnson, LES, An Innovative Development for Lighting System PerformanceEvaluation, Journal of the Illuminating Engineering Society, Volume 25 Number 2 Summer 1996, pp 117-127.

Overview

1-13

purchasing savings through demand-side bidding; and providing education anddemonstration facilities to the general public and to lighting professionals.

Of these three strategies, subsidizing lighting improvements has the greatest potentialimpact. Utility rebates can significantly reduce the installed costs, thereby acceleratingpayback periods and enhancing return on investment and life-cycle cost savings. Theresultant increase in the economic value of a lighting improvement makes the projectsignificantly more attractive to decision makers. Similarly, grants and attractivefinancing programs also encourage building owners to initiate lighting improvementsand save energy.

The Retrofit Process

Details of the retrofit process are presented in Chapter 2. Table 1-3 summarizes someof the key points.

Table 1-3The Retrofit Process

Phase Purpose Tasks

Qualification Determine if the building is a goodcandidate for lighting retrofits

Evaluate the quality of lighting in the space andassess the potential for improvements

Data Collection Collect information needed to performthe engineering study

Plan SurveyInterviewsShort-Term MonitoringAudit/Survey

Engineering Identify lighting retrofit opportunities,evaluate their cost-effectiveness, andmake recommendations

Assess Quantity/Quality IssuesDetermine Lighting SchedulesConfirming AssumptionsRetrofit Approaches—Relamping vs. RedesignEstimate Energy SavingsEstimate Retrofit CostsEconomic Analysis

Construction and Commissioning Implement cost-effectiverecommendations

Bid DocumentsBidding and/or NegotiationConstructionLamp and Ballast DisposalAsbestosCommissioningVerification and Measurement

Overview

1-14

The retrofit process will undoubtedly be different for each project, depending on itssize, complexity, and the magnitude of the opportunities. Clearly, not all the taskslisted in Table 1-3 will be carried out for every project. At one extreme, a lightingretrofit project might consist of going to the local hardware store and buying somescrew-in compact fluorescent lamps to replace incandescents. At the other extreme, itcan involve a detailed audit, short-term monitoring of the lighting system, engineeringfeasibility studies, prototype installations, bidding and negotiations, commissioning,and post-construction evaluation.

One of the tasks that is becoming more common with retrofit projects is to install short-term monitoring equipment, such as portable data loggers, to accurately measure hoursof lighting operation and determine the magnitude of the savings that are possible withoccupant sensors and other types of automatic lighting controls. In the past, it wascommon just to assume 4,000 hours/year for lighting system operation. Studies haveshown that actual hours can vary by 30% or more, creating significant errors in theprediction of energy savings. Short-term monitoring used to be a very expensive task;but with modern equipment, good data can be obtained at a very reasonable cost. Thismakes short-term monitoring, for instance through EPRI’s Lighting Evaluation System(LES), the recommended procedure for an increasing number of lighting retrofitprojects.

2-1

2 THE LIGHTING RETROFIT PROCESS

This chapter presents details of the lighting retrofit process, focusing on thedevelopment of a typical project from determining feasibility to commissioning andverification of energy savings. EPRI and others have developed tools to assist in thepreparation of lighting audits, and to analyze the information that is collected. Thesetools are referenced when appropriate. A special effort is made to review thecommunications that should occur between the various individuals and organizationsin each stage of a lighting retrofit project. Particular emphasis is directed tocommunication with the utility representative.

Overview

There are many variables that affect the lighting retrofit process such as the size andcomplexity of the building and the implementation method, e.g. utility audit withseparate construction contracting by owner; energy service company providing acomplete service, including financing; or some other implementation method. In spiteof these significant variations, the nature and sequence of activities in a lighting retrofithave been fairly well established over the years, through trial and error. The lightingretrofit process as presented in this chapter is as generic as possible. Most of the stepswill be carried out no matter what the implementation method or the buildingcomplexity.

Diagram of Process

Figure 2-1 is a flow chart of the general lighting retrofit process. The process isdescribed briefly here and more detail is provided later on each of the steps. Theprocess begins with a qualification audit to determine if retrofit opportunities aresignificant enough to warrant a more detailed audit and engineering study. If theproject has significant opportunities, then it will proceed through three phases: the datacollection phase, the engineering phase, and the construction phase. Usually at thecompletion of the engineering phase, some type of report or feasibility study isdelivered to management (or the decision makers) and a commitment is made to carryout the construction. The project then goes into the construction phase where bid (orconstruction) documents are prepared, the improvements are carried out, the systemscommissioned, and in some cases, post-construction monitoring and evaluation areperformed.

The Lighting Retrofit Process

2-2

Participation by the Utility Representative

Communication between the utility representative and building owner or facilitymanager is important at all phases of the retrofit process, but is critical at the beginning.Many owners will have no previous experience with lighting retrofits and the supportand encouragement of an electric utility may be just what is needed to push them to thepoint of considering a lighting retrofit.

Beyond the initial promotion of lighting retrofits, the services that the utilityrepresentative may provide will depend on programs in effect at the time. Asmentioned in Chapter 1, these programs may range from design assistance, where theutility may provide some or all of the auditing and engineering feasibility services, tofinancial incentives or rebates, to possibly a turnkey service similar to energy servicecompanies.


2-3

Figure 2-1 The Lighting Retrofit Process


2-4

The Players

In most cases, the utility will be intervening a lighting retrofit process that is alreadyunderway. The stage of the process and the players involved will usually be differentfor each building. To understand who the players are and what their roles are, youshould ask the following questions:

Who initiated the lighting retrofit? Is the owner responding to a proposal from anenergy service company; is there an in-house energy manager whose job it is topromote energy efficiency projects? Is pressure being applied on the landlord by anenvironmentally conscious tenant? Does the building owner simply want to increaseprofits by reducing operating costs?

How would the project be implemented? Is there a lighting maintenance company forthe building? Does this company provide retrofit services? Would the lighting retrofitsbe designed, implemented, and financed as a turnkey project by an energy servicecompany? Do the contracting policies of the organization require competitive bids? Ifso, is it acceptable to write closed specifications?

Who has the authority to commit to the project? Identify the individual or individualswho have the authority to make the go/no-go decisions. Does this person make arecommendation to a council or board? When does this board meet?

Is the proposed lighting retrofit a one-time project? If the building is part of a campusor one element in a collection of real estate holdings, there is a good chance that asuccessful lighting retrofit will lead to additional retrofits within the same organization.

Who will benefit from future energy savings and who will pay for the lightingretrofits? The answer to this question will help identify the motives of the variousplayers and determine if there are conflicting interests in carrying out a lightingretrofit. In the ideal case, there will not be conflicting interests, e.g. theperson/organization/department that pays for the lighting retrofits will enjoy theenergy saving benefits. Unfortunately, there are many instances when conflictinginterests exist. Following are some examples.

x In some governing jurisdictions, the cost of the retrofits must be paid out of theoperating budget of the department or agency that occupies the space. The benefitsof saving energy, however, may not directly benefit that department/agency, butrather some other agency with the responsibility for paying utility bills or providingenergy.

x In multi-tenant leased facilities, the contractual details of the lease will determinewhich party is responsible for paying for the lighting retrofits and which partybenefits from the savings.


2-5

— With some leases, the monthly cost to the tenants includes everything, and thelandlord is the sole beneficiary of energy savings. In many cases, the landlordwould also pay for the lighting improvements, perhaps through an allowancefor tenant improvements. The tenant would have no financial interest at all inthe lighting retrofit, although they would be negatively affected by disruptionsduring construction and positively affected by improvements in lighting quality.

— Other lease arrangements allow the owner to pass through operation costs forenergy, janitorial, etc. to the tenants on a prorated basis. Tenants typically pay afixed share of energy costs and there is no direct association with the energy useof the tenants own space. If a tenant takes measures to save energy, then theywould enjoy only a portion of the savings (the rest would be prorated among theother tenants).

— A third arrangement is for the tenants to pay their own utility bills. This is theopposite of the first case. The tenant would be the sole beneficiary of energysavings. Depending on the lease terms, either the tenant or the landlord may alsobe responsible for financing the improvements.

Information Resources

One of the most useful services that can be performed by the utility representative is toprovide reliable and credible information. Depending on the nature of the project andthe players involved (see above), the customer may be confronted with a plethora ofinformation on available technologies and equipment. The utility representative can beof enormous assistance by acting as a buffer between the customer and the vendorcommunity and by providing practical information about the expected costs andbenefits of various approaches. Several lighting information resources are available tohelp with the preliminary analysis.

General Lighting Information

In most cases, the utility representative will be a valuable source of generic informationabout available technologies, expected benefits, case studies of successful retrofits insimilar facilities, and details on the utility's incentive programs. The customer may askthe utility representative to evaluate product claims or suggest vendors. Potentially,this is a delicate subject. The most prudent response will usually be to provide generaltechnical information on the available technologies or equipment types, pointing outthe most relevant parameters to aid the facility manager in making an informed choice.Customers will find demonstration facilities to be an invaluable resource in sorting outcompeting technologies and manufacturer’s claims since these facilities allowcustomers to directly experience and compare lighting technologies. Appendix I is alisting of educational and laboratory facilities supported by utility companies, lampmanufacturers, and luminaire manufacturers.


2-6

Vendor Presentations

Equipment vendors and installers often make direct presentations to utility customers.These presentations are generally targeted at selling products or services. Sometimes,claims of product superiority and energy savings may be exaggerated or based oninaccurate assumptions. When claims are contradictory or confusing, a cautiouscustomer will seek additional information and clarification from the utilityrepresentative, an independent research or testing facility, or will visit one or moresuccessful installations. Sophisticated customers may also set up test areas on their ownpremises for side-by-side comparisons of competing products. After narrowing thefield to a manageable number, the facility manager will then obtain cost quotes fromthe remaining vendors and installers.

Independent Information

Independent research institutions such as EPRI, IESNA, and the Lighting ResearchCenter publish many useful reports, fact sheets, and case studies on energy-efficientlighting technology. Facility managers rely on these publications for objectiveevaluations of current technology. Similarly, some states have energy boards orcommissions that sponsor lighting research, publish results, set product standards, anddevelop building energy efficiency codes. In addition, many universities and nationallaboratories conduct research and issue publications on energy-efficient lightingproducts. On the federal level, the Environmental Protection Agency’s (EPA) GreenLights Program is a resource of both information and analytical tools for large-scalelighting retrofits.

Lighting Professionals

Lighting design and consulting professionals can provide expert opinions on theoptions confronting the facility manager. Some lighting professionals specialize inenergy efficiency and retrofitting applications. However, the majority of most lightingdesign work consists of new construction or new lighting in conjunction with extensiveremodeling. As such, a given lighting professional's experience with retrofittingexisting installations may be limited. When there are issues of lighting quality orlighting problems that need to be addressed, the services of a qualified lightingprofessional should be secured.

Qualification Phase

This phase is a preliminary screening to determine if a detailed lighting audit andengineering feasibility study is warranted. The qualification step may consist of a quickwalk-through of the building to observe the predominant type of lighting equipmentand to make a few spot measurements of lighting levels. On the other hand, it may


2-7

consist of a quick review of the plans and a few phone calls. In most cases, the utilityrepresentative can assist the customer in making this determination relatively quicklyand at a minimum cost.

To qualify (or disqualify) a facility, an experienced auditor or lighting professional canusually identify the major lighting system(s) from a walk-through of the building andquickly determine economic feasibility. For example, a building illuminated with 60-watt incandescent downlights operating 12 hours a day will likely be a cost-effectiveretrofit candidate. But a warehouse with skylights and photocell-controlled high-pressure sodium lighting is probably operating as efficiently as possible.

Example 2-1Qualification of a Hotel Project

Consider a hotel in which the hallways are lighted with 75-watt incandescentdownlights. The primary retrofit component would probably be compact fluorescentconversion kits. Each kit consists of a permanent socket, ballast, and reflector unit. 18-watt lamps would be used to maintain lighting levels similar to the existing condition.Each conversion kit would save an average of about 50 watts. At a utility rate of$0.08/kWh, electric costs would be reduced by about $4.00 per socket for every 1,000hours of operation. If the conversion cost $50 per socket, it would take 12,500 hours toamortize its cost; if the conversion cost $75, payback would occur in 18,750 hours. Awalk-through of the facility determined that some lights are operated 24 hours a day(8,760 hours per year), while others are operated about 12 hours per day (4,380 hoursper year). Under these conditions, retrofitting the existing incandescents is almostguaranteed to be cost-effective, as under even the worst possible conditions (all lightsoperating 4,380 hours per year, $75 per unit conversion cost and no rebate offered), theconversion would pay for itself in 4.3 years. Simple payback would occur within the 5-year deadline that is usually considered to be the longest acceptable payback period.


2-8

Table 2-1Clues to Determining Feasibility

Cost-Effective When: May Not Be Cost-Effective When:

x the facility has long hours of operation

x the lighting system was installed before1980 and has not been modified

x the electric utility has high demandand/or energy rates

x the utility actively practices DSM andoffers substantial rebates forreplacement of lighting equipment

x the facility has apparently high lightinglevels

x the facility has a preponderance of non-dimmed incandescent lighting

x other apparent and substantial energy-saving opportunities exist (e.g.unrealized daylighting)

x the facility has relatively short hours ofoperation, or operation of the lightingoccurs mostly at night

x the facility has been designed to exceedthe efficiency requirements of relevantenergy codes, such as California's Title24 (1985 or later), ASHRAE/IES 90.1—1989, including derivative codes in thestates of Washington, Oregon,Massachusetts, and Florida

x the building is a Federal governmentfacility that has been designed tocomply with the DOE Standard or withASHRAE/IES 90.1

x the facility pays relatively little forenergy and peak demand

x the facility is in a remote location orarea where competitive pricing ofretrofits might not be available

x the facility is not eligible for rebates orequivalent incentives

x the facility has recently undergone asuccessful lighting retrofit (there arecost-effective opportunities for oldretrofits and poorly executed retrofits)


2-9

Data Collection Phase

If the project passes the initial qualification (appears to be a likely candidate for alighting retrofit), then the next step in the process is to collect more detailed data. Thisincludes:

x reviewing architectural drawings and lighting plans if they are available

x interviewing building managers and/or operators

x collecting utility billing history

x installing short-term monitoring equipment to determine hours of lightingoperation and other data (optional)

x taking a detailed inventory of lighting equipment and controls on a space-by-spacebasis

Appendix H contains a suggested data structure and sample input forms for making alighting audit. It might be helpful for you become familiar with the information inAppendix H before making your first audit.

Plan Survey

The first recommended step in collecting data is to make a plan survey. The plansurvey is just like a walk-through survey, but is made by reviewing the plans. Thepurpose of the plan survey is to:

x Identify similar spaces that can be treated together. Whether or not they can actuallybe treated as similar spaces will be confirmed during the audit phase.

x Set up the data input forms and the data collection procedures.

x Understand the electrical branch circuits in order to plan the possible installation ofdata loggers or other short-term monitoring equipment.

Often the most accurate “as built” drawings and specifications are located in thebuilding engineer’s office at the building site. If this is the case, the plan survey mightbe scheduled as a part of the actual audit.

Similar Spaces

In most buildings it is possible to save time by reviewing the plans to identify spacesthat are similar and performing a detailed audit on a sample of the similar spaces. It isnot necessary for similar spaces to be truly identical. They should, however, be of


2-10

similar size, have the same type of lighting equipment, support similar visual tasks,and if daylighting is important, have similar windows and solar exposure.

Data Input Forms

It is a good idea to set up the data input forms during the plan review phase. Asuggested data structure is presented in Appendix H along with sample data inputforms. The surveyor should give each similar space a unique name and start a datainput sheet for each space. It may be possible to fill out much of the information on thedata input sheets from the plans, although all information should be verified in thefield. The surveyor will eventually walk through the entire facility, entering anymissing information on the data input sheets. Depending on the completeness of theavailable plans, the plan survey will provide some or all of the information listedbelow.

x Project Level Information. Information at this level should include the name, address,phone numbers, etc. of the utility customer, the building, the utility, and theauditor. In addition, milestone dates are often recorded. See Appendix H for asuggested data structure and sample input form.

x Lighting Fixture Schedule. If the plans include an electrical plan and lighting fixtureschedule the auditor can save time by using this information to start a lightingfixture schedule. The lighting fixture schedule is a listing of each unique fixturetype. The auditor should be aware that luminaires are often modified in the fieldand the information from the lighting plans should be considered a starting pointonly. When modified fixtures are discovered in the field, they should be added tothe fixture schedule. In general, each fixture type is assigned a code along withother descriptive information. When the surveyor performs a space-by-space audit,fixtures can be associated with the space through the unique code. Information inthe fixture schedule may also include luminaire performance data such ascoefficient of utilization, which is needed to perform light-level calculations.

x Space Level Information. Once similar spaces have been identified and organized, theauditor should measure and record the physical dimensions of each. Dimensionsshould include length, width, and ceiling height. This is also the best time to makenote of orientation, fenestration details, and daylighted areas within the space. Adaylighted area may be loosely defined as any area within the space that is adjacentto a window or windows, or that is under a skylight. See Appendix H for asuggested data structure and sample input form. When recording the luminaires foreach space family, it is also a good idea to review circuiting and assess obviousopportunities for energy-saving lighting controls. Most lighting control possibilitiesare dependent on occupancy patterns and daylight availability, which should beconfirmed during audit. However, the experienced auditor can usually recognizecontrol opportunities from the plans.


2-11

Electric Circuits

Identify dedicated lighting circuits for short-term monitoring of lighting hours. Forsome projects, you will want to install short-term data loggers or other monitoringequipment to determine typical hours of lighting operation and to verify base caselighting power estimates. There are many different types of data loggers, but a commontype measures current in electric circuits. Frequently, lighting and plug loads will be onseparate circuits so that the time of use of these circuits can be monitored on an hourlybasis. A review of the electrical drawings is the easiest way to identify such circuits andto plan the installation of data loggers.

What You Should Have after Completing the Plan Survey

Upon completion of the plan survey, the surveyor should have a data sheet for eachsimilar space, each with as much information as can be determined from the plans andschedules. Verify information gathered from the plans during the walk-through, asplans often differ from actual building conditions. If LightPAD 2.0 is being used toperform the audit, a project database would be started. The project database isessentially an electronic version of the data input forms contained in Appendix H. Ifusing LightPAD 2.0, carry a notebook computer into the field with the programinstalled and the project database residing on the hard drive.

Interviews with Building Operators

Identify the person(s) responsible for the operation of the building and set up a timewhen they can be interviewed. If possible, schedule the interview at the building site,where the operator can show you problems and point out peculiarities. Whenscheduling the interview, identify pieces of information that you will need so that theoperator can obtain this information prior to your interview. Use the following bulletsas a checklist. Be flexible, however, and ask any other appropriate questions.

x Try to get information on hours of lighting operation. Whenever possible, confirminformation with occupants and custodial staff. See more information below.

x Find out who the decision maker is, e.g. who will have the final say as to whether ornot the lighting retrofit will be implemented. Try to learn what level of economicperformance will be required for implementation, e.g. establish a maximum simplepayback, or if life-cycle cost analysis is to be performed, determine the discount rateand study period.

x Gain a better understanding of how the lighting retrofit (if cost-effective) will beimplemented. Will they use their maintenance contractor, union contractor, energyservice company, etc? You should know who will do the work and if possibleconsult with them before you estimate costs for the measures.


2-12

x Find out if the building has an energy management system and if the EMS has anydata recording capabilities. If so data may already be available for estimating hoursof lighting operation, which is needed for an economic analysis.

x Learn about maintenance practices. Are lamps changed as a group? How often?How often are luminaires cleaned? If the lighting system is poorly maintained, askwhat it would take to improve practices.

x Find out what utility rate the building is on and get copies of previous utility bills.These bills will be helpful in determining an average cost of electricity if the rateused demand and/or time-of-use charges. This information is needed in theengineering phase to convert electricity savings into cost savings. See Appendix Hfor suggested data input forms.

Lighting Survey (Audit)

The next step in the process is to perform the lighting survey (or audit). A lightingsurvey may be done with in-house personnel or by specially hired and trainedauditors. Product vendors sometimes offer lighting surveys, but they typicallyemphasize applications for their own products, possibly ignoring other products bettersuited to the application as well as other applications to which their products do notpertain. This survey is generally the most time-consuming step in the process and it isimportant to be organized and ready. Before you go to the site to perform the audit,you should already have a good idea of how many spaces you will need to visit fromthe plan survey.

The purpose of the survey or audit is to

x Verify dimensions, fixture types, and other information collected during the plansurvey.

x Measure lighting levels and record information about the cleanliness of luminairesand the age of the lamps which may be needed in adjusted measured levels.

x Interview space users about any lighting quality problems, e.g. is it too bright, toodim, or just right? Do they experience glare on their VDT screens?

x Gain more insight about hours of lighting operation. Are manual switches located ineach space? Are they used?

x Determine the visual task(s) that are taking place in the space.

x Take an inventory of lighting equipment in each space. Note the physical conditionof the equipment, the type of housing, lamps, etc. If the equipment is already in theschedule, then you will only need to mark the ID number from the schedule andindicate the quantity. If the equipment is not in the schedule, then you should addit.


2-13

x If lighting level calculations are to be performed, record information about thereflectances of the walls, roofs, floors in addition to the physical dimensions of thespace.

x If the space has daylighting, measure the illumination with the lights turned off.Note the sky conditions at the time of the measurement. If possible takemeasurements under different sky conditions, e.g. bright and sunny, cloudy andovercast, etc.

x Make note of retrofit opportunities.

The surveyor should have the following equipment and/or supplies:

x light meter

x measuring tape or infrared measuring device

x notebook or clipboard with space data sheets or cassette tape recorder (for recordinginformation to be transcribed).

x camera (still or video)

x notebook computer (if you are using LightPAD 2.0). Make sure you have sparebatteries or enough battery life to complete the survey.

Data collected during a lighting survey should be as complete as possible. Advancedsurveying tools such as EPRI's LightPad encourage data entry on the job site. This helpsreduce data collection time, costs, and errors. Whether or not a computer is used in thefield, a computer spreadsheet or database is a virtual necessity for managing largelighting surveys.

Most automated data collection procedures focus on replacement of specific luminairehardware. Unfortunately, relying strictly on rules for one-to-one replacements can leadto rote component substitution retrofits. Such substitutions may suggest delamping orother retrofits that are inappropriate to the application at hand. It is stronglyrecommended that an experienced and knowledgeable lighting professional assist theauditor in identifying retrofit opportunities that go beyond simple parts-swapping. SeeExample 2-2 for an illustration of how a knowledgeable lighting professional canimprove on a typical lighting retrofit strategy.


2-14

Figure 2-2 The Well-Equipped Lighting Surveyor

Example 2-2Going Beyond Energy Savings

An older office building with magnetically ballasted four-lamp lensed troffers on 8' by8' centers is to be retrofit. For most automated retrofit databases, as well as most utilityrebate programs, this is a classic retrofit situation with a textbook solution: convert theexisting magnetically ballasted T-12 systems to T-8 lamps and electronic ballasts;delamp, going from four to two lamps; add a specular reflector to increase luminaireefficiency. In most building spaces this will provide 40–60 maintained footcandles,while reducing power by more than 50%.

However, a skilled lighting professional, noting the extensive use of computer VDTscreens in the space, might suggest that retrofitting the troffers with VDT lenses orlouvers instead of adding reflectors (with resulting lighting levels of 30–40 footcandles)would make more sense from a lighting quality standpoint. This option would reducehigh angle glare and background-task luminance ratios, and would help preventveiling reflections caused by the imaging of the luminaires in VDT screens. Since thecost of the lens is about equal to the cost of the reflector, and energy savings match thatof the textbook solution, the owner and occupants would realize increased benefits.Being able to identify and report this opportunity is what separates the skilled retrofitprofessionals from mere mechanics.


2-15

Table 2-2Time-Saving Tips

Try dictating into a microcassette recorder instead of using pencil and paper. Your hands will be free to climb ladders and

open luminaires while recording ballast model numbers and lamp codes. Mention door or room number, occupant's name,

and describe each room as you walk in.

See if you can get a copy of a floor plan to make your own notations. Be aware that most plans will be inaccurate to some

degree; try to note major differences for easier reference by others. Fire exiting plans will often be available, if nothing else.

Take your camera or video camcorder—the pictures will jog your memory later. Remember to note what pictures you took

during your visit.

Photograph each lighting fixture type in the building and give it a name or tag like "F1" for fluorescent fixture #1. Use A for

incandescent, L for low voltage, H for HID, X for exit signs, etc. Indicate substantial differences between indoor and outdoor

luminaires. See the earlier discussion on Fixture Schedules.

Consider visiting some facilities at night to avoid interrupting occupants and explaining your purpose repeatedly. Be sure to

arrange for alarms to be off. Visit the building again briefly during the day to observe how lighting is actually used. Night

audits are also critical to confirm after-hours operation assumptions.

Consider possible energy conservation measures (ECMs) while you are still on site. You can optimize the amount of data you

collect and minimize return trips. Install lighting time loggers on the first trip and remove them on the last trip to get the

longest sample time.

When checking light level, use a good meter that is color and cosine corrected. (See Appendix E for information on measuring

light levels.) Take readings on work surfaces, desks, or at work-surface-specified height. Take multiple readings around the

room, or at least an average. Don't accidentally shade the meter with your body. Take readings with shades or blinds closed to

simulate night.

Consult IES standards to determine appropriate lighting levels for different tasks. Memorize the recommended lighting levels

and representative tasks for Tasks A-F.

Use an electronic distance measuring device rather than a tape.

Look at lamp stock, ballast stock, and fixtures in the midst of repair or maintenance in the building to determine the exact

technology, especially when checking fixtures is difficult.

Be clever to determine the age of the lighting system in each tenant space. Note spaces with aged lighting systems more

carefully; there will often be more cost involved but more credits based on deferred maintenance.

Note the operating voltage and means of control for each luminaire. If possible, use a voltmeter to determine panelboard bus

voltage. Look carefully for hidden lighting devices, like autotransformers or electronic dimmers used to change light level.

Source: Washington State Energy Office


2-16

Table 2-3IESNA Recommended Illumination Levels

Category Activity Illuminance, FC(Low-Medium-High)

Typical Spaces

A Public spaces with dark surround 2-3-5 Basements, quiet rooms

B Simple orientation for short visit 5-7.5-10 Corridor, Storage rooms, Night clubs

C Workspace with few visual tasks 10-15-20 Lobbies, Courtrooms, Elevators

D Visual task of high contrast (large) 20-30-50 Offices, general work space

E Visual task of medium contrast (small) 50-75-100 Offices, intensive work areas

F Visual task of low contrast (very small) 100-150-200 Drafting, art work, medical procedures

G Category F for prolonged period 200-300-500 Delivery rooms, autopsy tables, very difficultassembly, inspection

H Prolonged and exacting tasks 500-750-1000 Exacting assembly, dental work

I Special visual tasks 1000-1500-2000 Cloth inspection and perching

Source: IESNA Lighting Handbook, 1993

In most audits you will want to determine the existing illumination level in similarspaces. There are two general procedures that may be followed—calculations ormeasurements.

Calculations. The lumen method is the most common calculation method. This is themethod used by LightPAD 2.0. It is documented in Appendix D and explained more inthe next section.

Measurements. Procedures for making lighting level measurements are summarized inAppendix E and are described more in the next section.

Engineering Phase

During the engineering phase the tasks are to assess lighting quantity and qualityissues, establish lighting schedules for use in making estimates of energy savings,identify lighting retrofit opportunities, estimate retrofit costs, predict energy savings,determine economic feasibility, recommend a course of action, and report the findingsto management. In reality, there is not a clear line between the data collection phaseand the engineering phase, as most auditors will note lighting quality problems andbegin to identify retrofit opportunities while they are in the field.

Lighting Quantity and Quality Issues

Lighting Quantity

Lighting quantity or average illumination can be measured or calculated for each spaceand compared to the recommendations of IESNA or others (more is presented on this


2-17

later in this section). If a space is overlighted, there is an opportunity to reduce or tunethe lighting level to what is needed. This will save energy and operating costs, and ifthe retrofit is not too expensive, the cost will be paid for through the energy savings.

If a space is underlighted, the auditor is presented with a dilemma. For most lightingaudits, the general feasibility criteria is to recommend measures that will save enoughenergy to pay for the retrofit over some reasonable period of time. If a space isunderlighted and a lighting retrofit is proposed to correct the problem, energy use andoperating cost may be increased. Furthermore, the owner will have to pay for theretrofit. Unless the benefits of correcting the problem can in some way be quantifiedand factored into the analysis, a retrofit project that costs money and increases energyoperating costs, by definition, cannot be cost-effective. Many lighting retrofit projects,for instance those with energy service companies, are financed through the energysavings. In such cases, if there are no energy savings, there is no project. While it is notthe main purpose of energy efficiency lighting audits to uncover lighting problemssuch as underlighted spaces, the process of performing the audit usually reveals suchproblems; and it should be the responsibility of the auditor/surveyor to report suchproblems to the building owner and ask for direction1.

IESNA Recommendations

The IESNA recommends illumination levels for nine different categories of visual tasks.These are labeled A through I and are summarized in Table 3-3. Theserecommendations are determined by a consensus of lighting experts and establish anilluminance level for the average sighted person to perform the given visual taskwithout impairment.

Low, medium, and high values are recommended for each illuminance category. Thevalue to use depends on the following variables, commonly referred to as weightedfactors.

x Occupant or worker age. In general, older persons need more light than youngerpersons.

x Room reflectances or reflectance of task background. More light is needed ifcontrasts are great.

x Speed and accuracy. More light is needed if a critical visual task is beingperformed.

1 This problem is not unique to lighting improvements. It also occurs with retrofits to heating and cooling systems. The existingsystem may not be providing legal quantities of outside air or may not be maintaining comfort conditions. By correcting theseproblems, the HVAC retrofit project may actually increase energy use, or at least some of the savings will be negated bycorrecting the problems.


2-18

Table 2- gives the weighting to account for these factors. Weightings are determinedseparately for Illuminance Categories A through C as opposed to D through I. Forilluminance categories A through C you take account of occupant age and room surfacereflectances, using the following steps.

1. Determine the weighting factors separately for occupant age and room reflectances.

2. Add the two weightings, e.g. if occupants are under 40 (weighting factor -1) androom reflectances are in the middle range (weighting factor 0), the sum would be -1.

3. If the sum is -2 use the lowest of the three recommended illuminances. If the sum is+2 use the higher. Otherwise, use the middle value.

A similar procedure is used for Illuminance Categories D through I, except weightingsare determined for three factors and summed.

Table 2-4Weighting Factors Used in Determining Recommended Illuminance Levels

Weighting Factor

-1 0 +1

For Illuminance Categories A through C

Occupant Age Under 40 40-55 Over 55

Room Surface Reflectance Greater than 70% 30–70% Less than 30%

For Illuminance Categories D through I

Workers Age Under 40 40-55 Over 55

Speed and/or Accuracy Not Important Important Critical

Reflectance of Task Background Greater than 70% 30–70% Less than 30%

Source: IESNA Lighting Handbook, 1993. See this document for more details.

Determining Existing Light Levels. There are two ways to determine lighting levels inexisting buildings: through measurements or through calculations. Some auditing toolssuch as EPRI’s LightPAD 2.0 calculate the lighting level for each space so that it can becompared to recommended illumination levels.

Measurements. Measurements can be more accurate than calculations, but they aretricky. You must consider the cleanliness of the luminaires and age of the lamps.Lighting systems are designed to deliver a maintained illuminance, which is theillumination level that will be delivered at the end of the maintenance cycle, rightbefore the lamps are replaced and the luminaires cleaned. If you take measurementsright after new lamps have been installed and the luminaires cleaned, then it will benecessary to adjust the measured illumination. Similarly, if the lamps are beyond theirrecommended life and the luminaires are especially dirty, it may be necessary to cleanthe luminaires and replace the lamps before taking measurements. This will mean thatthe light level measurements will need to be adjusted for room surface dirt depreciation(RSDD) and lamp lumens depreciation (LLD).


2-19

In spaces near windows or under skylights, you must take separate measurements withand without daylighting. Recommended methods for making measurements aredocumented in Appendix E.

Calculations. When measurements are not feasible, a standard calculation can alsoprovide an estimate of average illumination. Appendix D presents the details of theLumen Method, which takes into account room dimensions and surface reflectances,lamp lumen output, general characteristics of the luminaire, and the Light Loss Factorof the system. Because this mathematical technique estimates the average roomilluminance, it will give misleading results if the room is illuminated very unevenly.Note also that the effects of daylighting and task lighting must be considered as well,because a low average illuminance estimate may be countered by natural light or tasklamps.

If the space is evenly illuminated and the lumen method is an effective estimate, thevalue calculated can be directly compared to the recommended illumination levelshown in Table 2-3.

Remedies. When a room is determined to have excessive illuminance, consider thefollowing retrofits:

x Replace existing lamps or lamp/ballast combination with lower lumen outputsystem (e.g. standard lamps to energy savers, high-output lamp/ballast system toslimline, etc.).

x Delamp existing luminaires; an additional option would be the installation ofoptical reflectors.

x Install ballasts with lower ballast factors, resulting in reduced lamp lumen output.

x Install dimmable ballasts with a photoelectric control system.

What to Do When There Is Too Much Light. Table 2-Error! Reference source notfound. summarizes applicable technologies, advantages, and disadvantages if a spaceis overlit: remove fixtures; remove lamps; use lower power ballasts lamps; and dim thelighting system.

Lighting Quality

Lighting quality can be recognized but remains hard to specifically define. High-quality illumination can result from good designs using modest lighting equipment, yetthe use of expensive lighting equipment does not guarantee good lighting quality.When lighting is retrofitted, it often presents an opportunity to improve the quality ofthe lighting as well as the energy efficiency.


2-20

Physical Appearance. Most lighting systems that are candidates for retrofitting areolder and have suffered periods of poor maintenance. Cracked and missing lenses,missing trims, parts that do not match, and other obvious problems are left unfixed formany years. Often the fixtures are dirty as well, and in extreme cases they are rusted,oxidized, and need painting.

Simply by cleaning and repairing the lighting system, its appearance is enhanced. Itmay also be a good time to paint the room’s ceiling or install new ceiling tiles, both torecover the reflectivity of the ceiling and to make the installation appear “as new.”

Color. Traditional cool white F40 lamps exhibit a greenish light long disliked by mostpeople. Likewise, mercury vapor lamps also create an unpleasant and eerie light. Evenwarm white fluorescent lamps are of poor color quality, emphasizing orangish-yellowcolor tones.

The modern light source replacements offer lamps with significantly improved color.A typical fluorescent retrofit involving T-8 lamps naturally improves the colorrendering index substantially; and at a minimum, space occupants usually observe thatcolors are more vibrant or people look better. While most of the time 4100K lamps areused to minimize before-and-after differences, sometimes the retrofitter uses 3500Klamps, which create a warmer-looking space as well. Similar results are possible inconverting mercury vapor lamps to metal halide or compact fluorescent.

The traditional warm glow of incandescent light remains a preferred light source color.Fortunately, a retrofit with fluorescent, metal halide or HPS can yield the same colorquality (or very close to it) provided the proper lamp is chosen. (Note that the wronglamp can cause damage).

Elimination of Flicker. Flicker is inherent in light sources operated from AC powersources. In every light source from incandescent through high-pressure sodium, thereis a presence of flicker that at a minimum can be annoying and that can causeheadaches and other physiological reactions. In industrial and sports applications,flicker is stroboscopy, causing moving or rotating objects to appear moving differentlyfrom reality.

High-frequency electronic ballasts for fluorescent lamps and square-wave or DCballasts for metal halide lamps can minimize flicker for these two important lightsources. While they still flicker, the percentage is reduced considerably; and relatedproblems, like stroboscopy are virtually eliminated.

Glare Control. There are two types of glare, discomfort glare and disability glare.Discomfort glare occurs when a light source is unshielded and very bright with respectto the surrounding surfaces. Disability glare occurs when glare obscures a visual task.Many sources of glare create both.


2-21

Table 2-5Options When There is Too Much Light

Remove Fixtures Remove Lamps Use Lower Power Ballasts orLamps

Dim the Lighting System

Often the existing spacing issufficiently close to allowremoving a percentage of theluminaires. In lay-in ceilings,consider rearranging fixturesso as to maintain acceptablespacing.

This can often be done withoutfurther modification; but foroptimum results, reflectors orother optical modifications mightimprove appearance.

Lower-wattage lamps are easy;low ballast factor for fluorescentlamps is a clever solution.

Dimming ballasts areexpensive but offer otheropportunities like daylighting;system dimming also worksbut without side benefits.

Applicable Technologies

Very simple and works well aslong as spacing-to-mountingheight is considered

Specular and white reflectors Low-wattage incandescent andhalogen lamps

Reduced wattage T-12 lamps(34- and 32-watt F40; 60-wattF96; 95-watt F96/HO)

Impedance modifiers

Low-watt T-12 lamps for T-8systems

Low-wattage metal halide

Reduced light output electronicfluorescent ballasts

Dimming electronic ballasts forT-8 and T-12 lamps

Dimmers for metal halide andHPS systems

Autotransformer voltagereduction to magnetic ballastsand tungsten loads (currentlimiters)

Waveform modificationdimming to magnetic andtungsten loads

Advantages

Low-cost solution withoutconcern for snap-back

A moderate-cost solution withoutconcern for snap-back.

Perform in conjunction withretrofitting new technology (T-8,CFL) for maximum savings

Maintains the originalperformance and appearance ofthe lighting system at a lowerpower level.

Perform in conjunction withretrofitting new technology (T-8,CFL) for maximum savings

Maintains the originalperformance of the lightingsystem at a lower power level.

Perform in conjunction withretrofitting new technology(T-8, CFL) for maximumsavings

Can permit dynamic controlslike daylighting and demandmanagement

Disadvantages

Can result in poor uniformity ifnot done well

Can result in a poorly-maintained appearance

May offer too little reduction Cost and complexity withdimming ballasts

Fluorescent lamp life problemswith system voltage reduction

HID color shift


2-22

Glare can be minimized by using lenses, louvers, or other forms of shielding. Sometypes of luminaires, like troffers, can be retrofit with lenses or louvers that improveglare control. In other cases, the addition of a lens or luminaire replacement canreduce glare.

Glare related to computer screens is the single most common disability glare problemencountered in retrofitting. Several lens and louver products exist that can be easilyplaced into plastic lens troffers to make them more suitable for computer work space.Because many older systems need new lenses anyway, the added cost of this featurecan be quite low.

Too Much or Too Little Light. Too much light is a form of glare, causing discomfort ordisability. Too little light can cause headaches, watering eyes, and other maladies.

Retrofits offer the opportunity to fix these problems. Because recommended lightinglevels of the IESNA have dropped since 1970 in consideration of energy efficiency,many spaces are overlighted and a retrofit program benefits from decreasing thelighting levels to an appropriate amount. In fact, the success of many retrofitprograms, particularly in the late 1980s, depended upon delamping and reducedlighting levels.

It is considerably more difficult to address too little light in a retrofit program.Increasing lighting levels, even if done efficiently, can increase energy use and undothe cost-benefit balance of a project. But because inadequate lighting levels are being“fixed,” it is generally recommended that this (and other types of remedial work) beisolated from both the energy-efficiency and cost-effectiveness calculations of thebalance of the retrofit project.

Other Quality Issues. Many things can affect illumination quality as well as theperception of quality by occupants. For example, the proper location and tactile qualityof a lighting control switch or dimmer can make an entire lighting system seem better.During the retrofit process, seek out small opportunities to convey a quality issue.

Lighting Schedules

One of the key tasks in the engineering phase is to identify and define the uniquelighting schedules appropriate for the project. Once the schedules are identified, one isassigned to the lighting system in each of the spaces. In existing buildings, you canestimate annual lighting hours through interviews with the building manager orbuilding owner, by projections from short-term measurements, or through an analysisof the utility billing history. There are three fundamental ways to define a lightingschedule: full-time equivalent (FTE) hours, FTE hours separated by time-chargeperiods, and hourly schedules. Each of these is discussed below.


2-23

Full-Time Equivalent Hours

The simplest way is in terms of the full-time-equivalent (FTE) hours. If you know theannual electricity consumption for a lighting circuit (kWh) and the peak power (kW),the FTE hours is the kWh divided by the kW. FTE hours may be used to estimate theenergy savings associated with reducing lighting power, and for flat utility rates withno demand charge, energy cost savings can also be accurately estimated.

FTE Hours Separated by Time-Charge Periods

If the utility rate for the project has time-of-use energy charges and/or demand chargesthat vary by time of use, it may be necessary to define lighting schedules in a moredetailed manner by separating the hours for different time charge periods. For instancewith many utility rates, the cost of electricity varies between summer and winter andby time of day. Table 2- shows how hours might be separated for a typical utility ratewith time-of-use charges. For this utility rate, it is necessary to split the hours betweenfive time-charge periods: summer on-peak, mid-peak, and off-peak; and winter mid-peak and off-peak. The details of the utility rate define these periods by time of day,day of the week, and season. To make it easier to perform the calculations, you shouldseparate days that define on-peak, mid-peak, and off-peak differently. For each time-charge period, you should multiply the hours per day times the number of days peryear. For instance in Table 2-, lighting is operated for six hours during the summer on-peak period from noon to 6:00 PM and there are 126 summer week days in the year. Thetotal lighting hours at the summer on-peak rate is therefore 756. This process isrepeated for the other time-charge periods.

Table 2-6Lighting Schedule with Time-of-Use Charges

Full-Time-Equivalent (FTE) Hours

$/kWh Weekday Saturdays Sun./Hol. Total

Summer On-Peak 0.12 6 h/d u 126 d n.a. n.a. 756

Summer Mid-Peak 0.08 5 h/d u 126 d 4 h/d u 26 d n.a. 734

Summer Off-Peak 0.04 3 h/d u 126 d 3 h/d u 26 d 2 h/d u 30 d 516

Winter Mid-Peak 0.07 6 h/d u 127 d 4 h/d u 26 d n.a. 866

Winter Off-Peak 0.03 8 h/d u 127 d 3 h/d u 26 d 2 h/d u 30 d 1154

Total n.a. 4026

With time-of-use rates, it is necessary to separately estimate energy savings for eachtime-charge period so that the correct rate ($/kWh) can be applied.


2-24

As a shortcut, some auditors calculate the virtual rate and use this in the same manneras a flat rate. The virtual rate can be calculated from the utility bills by dividing thetotal cost for electricity by the total consumption for a given time period. The timeperiod can be for an entire year, or for greater accuracy, you can calculate a separatevirtual rate for summer and winter.

Hourly Schedules

The most detailed way to define a lighting schedule is by hour of the day. This detail isneeded by hourly simulation programs such as DOE-2. For each hour of the year, youindicate the lighting power through a multiplier. The multiplier is usually a fraction ofthe peak lighting load. With computer programs such as DOE-2, hourly schedules arebuilt up. First, you divide the year into seasons. Next, you divide the weeks in eachseason into day types, e.g. weekdays, Saturdays, and Sunday/Holidays. Finally foreach day type, you specify a 24-hour lighting profile like those shown in Figure Error!Reference source not found..

The detail you include in your lighting schedules will depend on (a) the resources youhave to perform the audit (obviously it takes less time to define a schedule in terms ofFTE hours); (b) the tools you have at your disposal, and the data available to you (toconstruct hourly schedules you must have data from an EMS or measurements fromportable data loggers); (c) the type of utility rate that applies to the project; and (d) themethod you plan to use to estimate energy savings (if you plan to capture the HVACinteractions by using an hourly simulation program then you will need hourlyschedules). If you need an hourly schedule, EPRI’s Lighting Evaluation System (LES)provides an example of one approach to develop one (see Appendix C). You might alsoconsult ASHRAE/IESNA Standard 90.1—1989, which has default hourly lightingschedules for about 10 building types.

Figure 2-3 Example Hourly Lighting Schedule


2-25

General Approaches to Acquiring Data on Lighting Operation

There are several ways to collect data on the hours of lighting operation. These include:

1. Observing and/or Noting Use Patterns. This method relies heavily upon commonsense and its reliability is uncertain. The key is to interview a wide range of peoplefrom the building management staff to regular occupants to custodial staff. Forinstance, by interviewing building management employees, one can generallydetermine use patterns for certain types of lighting systems, like retail store lighting,classroom lighting, etc. where hours of operation are very predictable. However,even in many of these situations the manager may not be aware of off-houroperations, such as how long the cleaning crew leaves the lights on in the middle ofthe night; so night audits are important. Also, there may be seasonal variations inlight use that management is not aware of.

2. Using Recording Meters to Record Power Use on Lighting Circuits. This is a goodway to get a “snapshot” of daily use profiles of lighting energy in office buildings,schools, and other buildings, provided that the lighting circuits are isolated fromother loads. The power use profile measurements can be averaged over a sampleperiod; from them, a reasonable profile of building lighting energy use can beestablished for those circuits being measured. These profiles can be the buildingblocks for hourly schedules (see above). Choosing which circuits to measure is thekey to this method. However, even if the circuits are well selected, this techniquestill fails to provide time-of-use data for any particular light fixture or application.Also, seasonal differences will not be detected unless data are collected for an entireyear. The EPRI Lighting Evaluation System uses an advanced type of recordingsystem (see Appendix C).

3. Using Historical Lighting Use Data from an Energy Management System. Somemodern energy management systems are programmed to enable tenant use oflighting during preprogrammed periods and then require tenants to request andpay for extended hours of lighting operation. This method of wiring and controllingthe building effectively distributes energy cost differentials in the building amongtenants without submetering. If the historic use data for each tenant are available, itmay be possible to construct accurate lighting use profiles including seasonaldifferences. As above, however, data will generally not be provided for specificfixtures or applications.

4. Install Cumulative Lighting Loggers. Cumulative light loggers are self-containedlighting-activated instruments that record the amount of time a specific electricallight is energized. For the time period in which it is installed, the logger willaccumulate FTE hours. For modeling small buildings with simple electric rates, thisis a very good method; but for larger buildings with complex electric rates,cumulative light loggers will not provide data to enable you to split the hoursamong the time-charge periods.

5. Install Light Profile Loggers. Some loggers record both the time and duration oflighting use. Such loggers will record temperature, electric current or illuminationlevels, each of which can be associated with lighting use. At the end of themeasuring period, the logger is connected to a computer to download the time-series data. This method is very accurate for the luminaire or circuit being


2-26

measured. If enough recording loggers are used, detailed use patterns of specificrooms and lights can be generated.

Each of these methods of determining time of use produces data of increasing accuracyas the sample period and number of sample points increases. In particular, it isimportant to determine any seasonal variations that might taint the profile. Quarterlysamplings can resolve this problem.

Practical Data Collection

As a practical matter, the surveyor will often have a little of each type of data.Engineering judgment and common sense can help sort through the data and constructreasonable schedules for use in analysis. With a minimum amount of time to takemeasurements, and often a limited instrumentation budget, it is still possible to obtainsufficient information to use in retrofit analysis. The following steps are suggested:

1. Interview building operators, users, and custodial staff to determine as much aboutlighting systems operations as possible.

2. Observe lighting operations at different times: early morning, late afternoon,evening, weekends, etc.

3. Gather any data available from an energy management system or electricsubmeters.

4. Based on observations and interviews, identify the number of unique lightingschedules that exist in the building. This may include several “manual” schedules.

5. Use portable data loggers to collect (or supplement) information on each of theunique lighting schedules identified above. For representative lighting circuits orluminaires, collect data for at least one week. If the profile is simple and obvious,with a clear-cut schedule and a consistent load, it can be used to establish thebaseline and help with analyzing retrofit options.

6. If there is a clear profile but with load changes throughout the day, data loggers canbe placed within luminaires suspected of having time-differing use patterns.

7. If there is not a clear profile, data loggers can be placed within luminaires suspectedof having differing schedules.

8. For spaces with daylighting controls or in spaces that are candidates for daylightingcontrols, consider using a light logger to determine times when useful daylight isavailable. Keep in mind that seasonal and weather variations can be significant.Calibrate the light logger with an accurate light meter.

For each luminaire, it should be possible to create an average daily profile. The mostdifficult will be fixtures in daylighted spaces, especially if manual control is involved.


2-27

Other difficult situations include similar spaces, like private offices, under the manualcontrol of the occupant.

Typical Schedules

Hours of lighting operation are very dependent on the building type. For instance,buildings that are always open, such as hospitals, will operate their lighting systems formore hours than an average office building, which is only open during the day. A 1986study by the U. S. Department of Energy found that the lighting systems in the averagenonresidential building operate for 3,500 hours per year, but that the hours varyconsiderably with building type. Estimates by building type are summarized in Table2-, and these values may be used in calculations when better data are not available.

Table 2-7Hours of Lighting Operation Typical Values

Building Type Annual Hours of Operation* Building Type Annual Hours of Operation*

Assembly 2760 Mercantile 3325

Education 2605 Office 2730

Food Sales 5200 Public Order & Safety 6365

Food Service 4580 Warehouse 3295

Health Care 7630 Others 4400

Lodging 8025

Source: Energy Information Administration, U. S. Department of Energy.

* Based on 50 weeks per year operation

Short-Term Measurements

The availability of modern building monitoring and verification equipment hasdramatically improved the ability to estimate accurately operating hours for lightingsystems. A wide variety of inexpensive, pocket-sized, battery-operated data loggers areavailable for making short-term measurements. Data loggers are available to senselight, occupancy, electric current, electromagnetic fields, temperature, relativehumidity, and other parameters. Data loggers of most interest in lighting retrofit worksense light, occupancy, or electric current. However, other types of sensors can be used.For instance, temperature sensors can be used to monitor the on/off state of a luminaireif the temperature sensor is placed near the ballast. Data loggers record information inone of three ways, described below:

x Run-time loggers. Some loggers record cumulative hours, commonly called run-time loggers. These loggers usually sense only whether a condition is true or false,e.g. current is passing through a conductor or it is not, a space is occupied or it is


2-28

not, or light is being produced by a luminaire or it is not. When using this type oflogger, you must determine the lighting power through other means.

x Time-of-use loggers. Time-of-use loggers work like run-time loggers, but record thetimes the state changes. For instance, they record the time when current begins topass through a conductor and the time when current stops. Again you mustdetermine lighting power through other means.

x Quantity loggers. Finally, some data loggers record the strength of the signal,which can be converted to a quantity of current, temperature, light level, etc. Thistype of data logger takes a snapshot of the quantity at specified time intervals,adjustable from about 5 minutes to a couple of hours.

Both time-of-use and quantity data loggers usually come with hardware and softwarethat enables information to be uploaded to personal computers through a serial port.The various types of portable data loggers most applicable to lighting retrofit work aresummarized in Table 2-.

In addition to miniature, portable, self-contained data loggers such as those describedabove, more complex data monitoring systems can be constructed from basiccomponents. For instance, general purpose, multichannel data loggers are available thatwill measure and record information from both analog and digital sensors. With thistype of system, you can separately select sensors to measure current, temperature, light,occupancy, or just about any other signal.

Table 2-8Summary of Portable Data Logger Types for Lighting Retrofit Work

Type

TypeofSensor

Run Time:records the cumulativehours when:

Time Of Use:Records the timeat which:

Quantity:At specified timeintervals, measures:

Occupancy Passive infrared orultrasonic

a space is occupied a space becomes occupiedor unoccupied

n.a.

Light Photocell a luminaire is on a light is turned on or off light level

Electric Current Clamp-on current sensor current is flowing current begins to flow orceases to flow

current

Note: Other data loggers are available to measure temperature, voltage, relative humidity, and other variables.


2-29

Example 2-3Using Monitored Data

An office space is leased to a law firm. Most of the space consists of 40 private officeswhich are controlled by manual switches. A series of lighting retrofits is beingevaluated, including occupant sensors and retrofitting the luminaires with T-8 lampsand electronic ballasts. In order to estimate the savings, a schedule is needed torepresent the current hours of lighting operation for the private offices. A secondschedule is needed to represent the pattern of lighting operation that would occur if allthe offices had occupant sensors.

A sample of four private offices are selected at random (10% of all offices). This samplewill be used to determine schedules for all the private offices. Two data loggers areinstalled in each office. The first is a time-of-use data logger that records the state of thelights. Data from these data loggers will be used to construct a schedule representingcurrent lighting operation. The second data logger is a time-of-use occupancy datalogger. This will provide information that will be used to modify the first schedule.Both data loggers are installed for a period of two weeks. Since there are no holidaysduring this two week period, the data loggers will collect information for 10 weekdays,two Saturdays and two Sundays.

Most quantity data loggers take a snapshot of the signal strength at specified timeintervals, which can be set on the data logger. If the data logger were set to recordcurrent every 30 minutes on the hour and half-hour, then all that would be recordedwould be the current at those instances. If for some reason, the current came on for ashort period of time around the hour and half-hour and was off the rest of the time,most quantity data loggers would not detect this. Although this is usually not aproblem, more advanced quantity data loggers are available that integrate the signalover each time interval. Suppose that current was zero for the first 15 minutes of a 30minute time step and 10 amps for the second 15 minutes. A standard quantity datalogger would record 10 amps, while the integrating type would record the averageover the time period of 5 amps.

The type of data logger that is appropriate for your job depends on the type of schedulethat you need to develop (FTE hours, FTE hours separated by time-charge period, orhourly). If you need only FTE hours, then the cumulative type data logger isappropriate and will save time in analyzing data. By measuring the hours of operationfor a typical week, an annual schedule can be projected.

Before embarking on a short-term monitoring effort, you should do some planning.Based on your judgment and observations of the building and its lighting systems,identify the unique lighting schedules that you believe to exist in the facility. You maybe able to estimate the hours of operation for some of the schedules without monitoring


2-30

data. For instance, the schedules in hallways and other common areas are usually verypredictable and a reasonable estimate can be made through interviews with users andoperators of the building. Concentrate on those schedules for which you needmonitored data.

When using data loggers that record current, be sure to account for the power factorwhen converting to energy kWh. Most data logger software is set up to make thisadjustment. A good way is to correlate the current to the power measurement from aportable watt meter.

EPRI’s Lighting Evaluation System and Lighting Diagnostics and CommissioningSystem both use portable data loggers. See Appendix C for more information.


2-31

Example 2-4Determining Hours of Lighting Operation

A two-story office building of about 20,000 square feet has the following spaces and uses:

x Common main lobby, 24-hour operation, 2,000 ft2. The lobby is always open and has a guard onduty.

x Second floor elevator lobby and corridors, 24-hour operation, 1,500 ft2. It is always open.

x Building core area, including stair towers and elevator shaft, 800 ft2. The stair lights are onemergency and always on.

x Restrooms, 1,000 ft2. There is a switch at every restroom door and the guard is supposed to turn thelights off during off hours.

x Mechanical, electrical, maintenance, and janitorial, 700 ft2. Each space has a switch but the lights aresupposed to be left off.

x Main floor tenant #1, 3,500 ft2, travel agent with open area, one conference room and two privateoffices. Business hours are 8:00 AM to 5:00 PM M-F and 10:00 AM to 5:00 PM Saturday. The office isgenerally empty by 6:00 PM.

x Main floor tenant #2, 3,000 ft2, retail store, with 500 ft2 of back-of-house space. Business hours are10:00 AM to 6:00 PM, Monday through Thursday, 10:00 AM to 9:00 PM Friday, and 10:00 AM to 5:00 PM

Saturday.

x Upper level tenant #3, insurance agency, 5,500 ft2, with 10 private offices, conference room, andopen office area. Business hours are 9:00 AM to 5:00 PM M-F but the principals work 60 hours perweek including evenings and weekends.

x Upper level tenant #4, architect, with one large drafting room and a conference room. The office isgenerally open by 8:30 AM M–F by the receptionist but work hours are very flexible.

x Building management indicates that cleaning occurs between 6:00 PM and 2:00 AM Sunday throughThursday.

x The utility rate structure includes separate demand and energy charges with different energy ratesfor on-peak and off-peak. The peak period is 10:00 AM through 6:00 PM M–F.

Cumulative light loggers are placed in the following locations: rest room, store (front and rear),reception area of each office space, and several principals’ offices of tenant #3. Measurement period isa typical spring week. The available data are listed as follows.

Lighting System Normal Hours/Week Cleaning Hours/Week Logger Reading Comment

Lobby, Elevator Lobby, and Core 168 n.a. n.a.

Restrooms Unknown Unknown 135

Tenant #1— Reception 58 10 72 68 estimated, 72 measured,say 70

Tenant #2—Store 50 10 71 Stocking and/or close-outtakes some time—use 70hours

Tenant #3—Reception 40 10 79 Reception lights on during latehours

Tenant # 3—Principal A 40 10 77 Works late hours

Tenant #3—Principal B 40 10 67 Normal hours

Tenant # 4—Open Area Not sure 10 74 Makes sense


2-32

Example 2-4Determining Hours of Lighting Operation (continued)

From observations, it appears that the lobby, core, and shell lighting can be assumed to operate full time (168hours/week). Meanwhile, almost all spaces seem to be operating about 70 hours per week (3,640 hours per year).All li ghting operates during peak periods. From these data, the following chart may be developed.

Use Period Multiply Daily Hours By Annual On-PeakHours

Annual Off-Peak Hours

Business Day On-Peak 8 x 250 = 2000

Business Day Off-Peak 2 x 250 = 500

Weekend Day 10 x 104 = 1040

Holiday 10 x 15 = 150

TOTALS 2000 1690

For this example building, the annual use profile is 2,000 on-peak hours and 1,700 off-peak hours, for an annual total of 3,700 hoursfor tenant space lighting and 8,760 hours for public spaces lighting. As a check, this corresponds well to national averages of 3,500annual office building lighting hours per year.

Confirming Assumptions

Each step in the process offers an opportunity to confirm assumptions made in theprevious steps. It is not unusual to learn something along the way that affects theprogram, even to the point where a project is significantly changed or even abandoned.These data, welcome or not, should be continuously assimilated lest a project fails tomeet performance requirements.

Some typical examples:

x A scoping study might assume the use of 40-watt lamps (optimistic) or 34 watts(pessimistic) based on a rough fixture count. As the detailed fixture count iscompleted, an accurate count of EACH lamp type should be made to establish thebest possible baseline.

x Even in the “audit” phase, an assumption about the type of ballast is often made.The actual number of each type of ballast may not actually be known untilluminaires are actually opened up for retrofit. In addition to the energy-relatedcosts, the disposal costs of PCB-containing ballasts may also be impacted.Although at this point the project is committed, it still might be valuable to updatethe expected performance values.

x Surprisingly, quite a few analyses discover that the utility rate being billed to thecustomer is incorrect. Checking this may reveal a rate too high or too low, orperhaps, a rate that might need to change because of the retrofit.

x A dimming system might be discovered, such as an autotransformer or electronicdimmer. These systems, which were applied to branch circuits or panel boards,


2-33

might be operating lighting systems at dimmed levels that are not readily obvious.These devices might not be discovered until construction, and once again, radicallychange the expected savings results.

x Assumed hours of operations are frequently guesses. Even if the project isproceeding, data could be collected using loggers or even just observations bysurveyors. Operating hours are among the most difficult data to accumulateanyway; so updating with more accurate data will only help create a more realisticbaseline.

x Cross-check assumptions with metered electrical data when it is available.Compare both energy (kWh) and demand (kW). If the building is on a time-of-use(TOU) rate, compare energy and demand for each charge period, e.g. on-peak, off-peak, etc.

Some projects require that energy savings predictions be met in order to meet economicperformance criteria. In these cases, ongoing data input and corrections are essential tokeeping the predictions as accurate as possible.

Retrofit Approaches—Relamping vs. Redesign

Often, the strategy of relamping must be compared with a decision to change theexisting luminaires entirely. This is particularly relevant in situations where issues oflighting quality arise. Such a situation might arise, for instance, in an office with heavyvideo display terminal (VDT) use, illuminated by traditional fluorescent troffers. Acommon problem with lighting designs in areas of high VDT usage is the presence ofveiling glare on the work task (the VDT screen), due to reflectance produced by theoverhead fixtures. Relamping to more efficacious lamps in such a case will generallynot solve the glare problem. Instead, the retrofitter must usually modify or replace theexisting luminaires, often by installing small paracube louvers, or by using new fixturessuch as indirect lighting. Alternatively, the existing luminaires (or work areas) could berelocated so as to move the source of glare away from the task zones.

Another application in which relamping may be incorrectly applied as a retrofitstrategy occurs when poor lighting design or a change in occupancy or work patternshave created severely underlighted areas in the space. Sometimes, this problem can besolved by relamping with brighter lamps. However, there are situations where a simplerelamping will not be sufficient to solve the lighting design problems. These conditionswill require a complete redesign of the lighting system, including relocation and/orreplacement of the existing luminaires.


2-34

Estimating Energy Cost Savings

An essential task in evaluating whether an efficient lighting system is worth theadditional cost is to estimate the annual energy use of alternative designs. With lightingsystems, the energy used is simply the connected lighting power multiplied times theannual hours of operation. Both lighting power and the hours of operation areestimated separately for the base case and the lighting retrofit. Lighting power for thebase case is determined from the audit. Lighting power for the retrofit condition isdetermined from engineering estimates or measured from test installations. The hoursof operation for the base case can be reasonably estimated by interviewing the buildingmanagers, evaluating submeter data, or through the use of short-term monitoring (seeearlier discussion). If automatic lighting controls are to be included as part of theretrofit package, the hours of lighting operation should be adjusted for the lightingretrofit case.

To calculate lighting electricity use when a time-of-use electric rate applies to thebuilding, you will want to separate the hours of operation for each time-charge periodand separately estimate electricity use for each time-charge period (see earlierdiscussion).

You should also consider the indirect benefits of reducing lighting power. Lightingsystems add heat to buildings that must be removed by the air conditioner. Therefore,efficient lighting systems have the added benefit of reducing air conditioning load.Depending on the efficiency of the air conditioner, the building type, and the climate,air conditioner savings can equal 10– 30% of the lighting energy savings.

Lighting systems in most commercial buildings operate during the peak period, so akW of reduced lighting power is also a kW of peak demand reduction. Since airconditioners also generally operate in the peak period, and a more efficient lightingsystem reduces air conditioner load, additional demand reduction is realized. Theadditional reduction will depend on the efficiency of the air conditioner but will rangebetween 30–50% of the lighting demand reduction. For electric rates with a demandcharge, the monetary savings from an efficient lighting system are the sum of theenergy savings and the savings due to demand reduction.

A calculation procedure is presented in Figure Error! Reference source not found. thatmay be used to estimate both the direct lighting cost savings and the indirect costsavings due to reduced loads on the air conditioner. The calculation considersreductions in both energy use and electric demand. An explanation of the calculationfollows the calculation form.

The calculation procedure in Figure Error! Reference source not found. may be usedfor buildings that have rate schedules where the cost of electricity does not changeduring the course of a day. Many electric rates for commercial buildings are more


2-35

complex, however, and require that the estimate of kWh and kW be made separatelyfor each time-charge period. With time-of-use rates, it is necessary to divide theelectricity energy use into separate bins for each time-charge period. For instance if theutility charges a different rate for electricity used between noon and 6:00 PM, theestimate of annual hours is divided between those hours that occur between noon and6:00 PM and all other hours. Energy use is separately calculated for each time periodand the applicable rate is applied. The procedure in Figure Error! Reference source notfound. can be modified to include some of these details.


2-36


2-37

Figure 2-4 Calculation Form for Estimating Energy Cost Savings (continued)


2-38

Table 2-4Fraction of Annual Lighting Heat to Cooling and Heating

Fraction of Lighting Heat to: Fraction of Lighting Heat to:

Location Cool Heat Location Cool Heat

Alabama Iowa

Birmingham 0.57 0.09 Council Bluffs 0.40 0.32

Huntsville 0.53 0.11 Mason City 0.34 0.39

Mobile 0.66 0.01 Sioux City 0.38 0.36

Montgomery 0.61 0.06 Kansas

Arizona Dodge City 0.44 0.26

Flagstaff 0.32 0.37 Goodland 0.41 0.30

Phoenix 0.71 0.00 Kansas City 0.44 0.22

Tucson 0.69 0.02 Wichita 0.47 0.19

Arkansas Kentucky

Blytheville 0.51 0.16 Covington 0.42 0.25

Fort Smith 0.53 0.14 Hopkinsville 0.49 0.17

Little Rock 0.54 0.11 Louisville 0.46 0.22

California Louisiana

Barstow 0.56 0.10 Alexandria 0.64 0.03

Bishop 0.53 0.15 Lake Charles 0.68 0.02

Los Angeles 0.56 0.00 New Orleans 0.68 0.02

Sacramento 0.49 0.04 Shreveport 0.61 0.05

San Diego 0.52 0.00 Maine

San Francisco 0.38 0.02 Portland 0.27 0.36

Santa Barbara 0.21 0.05 Massachusetts

Colorado Boston 0.34 0.27

Colorado Springs 0.37 0.29 Springfield 0.35 0.35

Denver 0.39 0.29 Michigan

Grand Junction 0.41 0.29 Detroit 0.33 0.31

Trinidad 0.44 0.30 Grand Rapids 0.33 0.35

Delaware Lansing 0.34 0.32

Dover 0.41 0.23 Sault Sainte Marie 0.22 0.41

Wilmington 0.41 0.32 Traverse City 0.29 0.38

Florida Minnesota

Miami 0.87 0.00 Duluth 0.22 0.42

Jacksonville 0.72 0.02 International Falls 0.24 0.44

Orlando 0.80 0.00 Minneapolis 0.33 0.39

Pensacola 0.66 0.01 Mississippi

Tampa 0.80 0.00 Biloxi 0.65 0.01

Georgia Columbus 0.59 0.10

Atlanta 0.52 0.10 Montana

Augusta 0.61 0.08 Billings 0.32 0.36

Macon 0.60 0.06 Glasgow 0.30 0.41

Idaho Great Falls 0.29 0.37

Boise 0.34 0.26 Helena 0.27 0.38

Lewiston 0.33 0.24


2-39

Table 2-9Fraction of Annual Lighting Heat to Cooling and Heating (continued)



Nevada Oregon

Ely 0.35 0.36 Burns 0.30 0.35

Las Vegas 0.61 0.05 Eugene 0.26 0.14

Reno 0.36 0.25 Medford 0.37 0.19

Winnemucca 0.39 0.30 Pendleton 0.35 0.24

New Hampshire Portland 0.27 0.14

Manchester 0.33 0.37 Pennsylvania

New Jersey Philadelphia 0.41 0.24

Trenton 0.40 0.28 Pittsburgh 0.38 0.30

New Mexico Scranton 0.35 0.34

Alamogordo 0.56 0.14 Williamsport 0.36 0.31

Albuquerque 0.47 0.20 Rhode Island

Clovis 0.51 0.17 Providence 0.32 0.29

New York South Carolina

Albany 0.34 0.35 Charleston 0.62 0.05

Buffalo 0.33 0.34 Columbia 0.58 0.09

Syracuse 0.34 0.35 Myrtle Beach 0.56 0.08

New York City 0.35 0.24 South Dakota

North Carolina Huron 0.35 0.41

Greensboro 0.49 0.16 Rapid City 0.34 0.36

Raleigh 0.52 0.14 Sioux Falls 0.35 0.39

Wilmington 0.58 0.05 Tennessee

North Dakota Knoxville 0.50 0.16

Bismark 0.32 0.42 Memphis 0.53 0.13

Fargo 0.29 0.42 Nashville 0.49 0.14

Grand Forks 0.29 0.42 Texas

Minot 0.28 0.42 Amarillo 0.49 0.19

Ohio Corpus Christi 0.74 0.01

Cincinnati 0.42 0.25 Dallas 0.60 0.07

Cleveland 0.36 0.31 Houston 0.73 0.02

Columbus 0.41 0.27 Lubbock 0.53 0.14

Dayton 0.42 0.29 San Antonio 0.71 0.03

Toledo 0.37 0.33 Utah

Oklahoma Salt Lake City 0.34 0.29

Altus 0.54 0.02 Wendover 0.37 0.29

Enid 0.49 0.16 Vermont

Oklahoma City 0.51 0.17 Burlington 0.29 0.39

Tulsa 0.51 0.17 Virginia

Richmond 0.46 0.16

Roanoke 0.46 0.18


2-40

Table 2-9Fraction of Annual Lighting Heat to Cooling and Heating (continued)



Washington Wisconsin

Seattle 0.16 0.17 Green Bay 0.30 0.39

Spokane 0.27 0.32 Madison 0.35 0.38

Washington, DC Milwaukee 0.36 0.36

0.45 0.23 Wyoming

West Virginia Casper 0.33 0.37

Charleston 0.45 0.22 Cheyenne 0.32 0.35

Clarksburg 0.39 0.30 Rock Springs 0.29 0.40

Source: Rundquist, R.A., Karl F. Johnson, and Donald J. Aumann. “Calculating Lighting and HVAC Interactions,” ASHRAE Journal,November 1993.

Some rates include "ratchets" that consider the demand history of previous months incalculating billing demand. For these and other more complex rates, you may want toconsider the use of computer simulation programs such as DOE-2, PowerDOE,COMTECH or other commercially available programs, which can model more complexthermal interactions and utility rates. With such programs, you will build a morecomplete model of the building, including building envelope descriptions and HVACsystems. Interactions between heat produced by the lights and air conditioning energyare calculated for each hour based on the thermal loads and internal loads at that hour.This more accurate method requires detailed information about the entire building, notjust the lighting systems. Furthermore, hourly schedules of operation are needed, notjust FTE hours.

Replacement and Maintenance Costs

In comparing alternative lighting designs, other operating costs, such as lamp andballast replacement costs and maintenance, should also be considered. Estimates ofmaintenance and replacement costs can be obtained from maintenance contractors andlamp manufacturers. The most critical factor is usually the estimated lamp life. This canrange from 750 hours for some standard incandescent lamps to more than 20,000 hoursfor some high-intensity discharge lamps. Compact fluorescent lamps usually have arated life of about 10,000 hours. Lamp life data are provided by manufacturers basedon three hours per start for most fluorescent lamps and ten hours per start for HIDlamps.


2-41

Group relamping should be considered in all maintenance programs. Not only canlabor costs be reduced, but it is easier to maintain uniform lamp color and brightness.In addition, lamp replacement costs may be lower because lamps can be purchased involume at a discount. Group relamping can also save energy if lumen maintenancecontrols are installed. Group relamping can usually be performed in conjunction withfixture cleaning and maintenance, and can be scheduled at times when the building isnot in use to prevent disruption of normal operations. Keep this in mind as actualoperation time can dramatically affect lamp life, especially with fluorescent lamps.

Economic Analysis

Once all costs are known, the cost-effectiveness of design alternatives should beevaluated. The most common measure of economic performance is simple payback,which is the length of time (in years) that it takes for the energy savings to equal theinitial investment. Simple payback is easy to calculate and is understood by mostpersons, but it has some limitations. For instance, it can only be used to compare twocompeting alternatives. If more than one alternative is to be evaluated, they must becompared to a single base case. In common usage, simple payback does not takeaccount of differences in maintenance costs or replacement costs that may be imminent.

Other measures of economic performance include net present value (life-cycle cost),internal rate of return, benefit-to-cost ratio, and annualized cost. These concepts arediscussed in greater detail in Appendix F. Appendix F also includes present worthtables needed for economic evaluation of alternatives.

Construction and Commissioning Phase

Bid Documents

Engineering is completed with sufficient drawings and/or specifications to allow theinstaller to accurately determine a price and successfully complete an installation. If theentire process is handled by a single company, such as an ESCO or a lightingcontractor, the technical specifications may be minimum, as the "turnkey" suppliergenerally assumes all risks. However, if independent engineers are preparing contractdocuments for obtaining bids from competing contractors, complete documentation isabsolutely required.

Final engineering drawings and specifications include the kind of informationgenerally not needed during engineering analysis. A retrofit of 2'x 4' lens troffers, forinstance, can be studied as if the troffer were "generic." However, in final engineering,the retrofit engineer will find that many of the parts, such as the reflector/socket kit orthe lens, must be ordered specifically for the manufacturer, product, and (in some


2-42

cases) the product version or year. If the final engineering documents fail to identify aspecial problem or condition, such omission could add substantially to the cost of aretrofit and therefore ruin the payback. It is important for the bid documents to includethe commissioning tasks expected of the contractor (see below).

A typical example involves lenses. Some office buildings designed in the 60s and 70semployed ceiling systems of non-standard dimensions. Luminaires have been found tohave actual dimensions of 27" x 54", instead of 24" x 48". All other factors—lamp,ballast, reflector— are fairly standard. But the lens cost is about 400% of the standardlens. Such an oversight would probably cost the building owner about twice thedifference, or about 600% of the lens cost. The net effect would be to raise the projectcost about $15 per luminaire, significantly reducing the cost-effectiveness of themeasure.

Bidding and/or Negotiation

In this task, a contractor is selected; or if one has already been selected through aseparate process, a construction contract is negotiated. Because there are always uniquefield conditions that escape the notice of the lighting auditors, contractors who blindlyfollow specifications without caution or flexibility should be avoided. It isadvantageous to have a contractor with the skill and experience to recognizeunexpected situations and to discover specifications that seem not to make sense in agiven space. These areas of work should be temporarily skipped until thespecifier/designer is contacted and a decision is made on how to address the problem.

Construction

During construction, the designer or construction manager should work closely withthe occupants to explain the purpose of the retrofit and to schedule access. This can be avery time-consuming task, especially when there are areas that have security accessrestrictions or that contain delicate apparatus that may be damaged by constructioncrews. The designer or construction manager should also work closely with thecontractor(s). Field conditions will frequently differ from those specified in the contract,and decisions will often need to be made to modify the specifications for non-conforming areas.

Lamp and Ballast Disposal

Relamping as a retrofit strategy introduces the problem of what to do about thedisposal of old lamps. Fluorescent and HID lamps, for example, contain small amountsof mercury. Although the Environmental Protection Agency currently has norestrictions covering the disposal of lamps, this is expected to change. Some states, suchas California, regulate the quantity of fluorescent lamps that may be disposed of at one


2-43

time. The retrofitter is responsible for learning of any federal, state, or local regulationsregarding the disposal of old lamps and/or ballasts. In case of doubt, fluorescent lampsshould be disposed of through a company licensed to dispose of fluorescent lamps ormercury products. Most HID lamps also contain mercury and require similar disposalprecautions.

You should identify a licensed disposal company in your area and obtain costs to use inthe analysis. The following costs are fairly typical for 1996. Full-size fluorescent lampdisposal costs range from $0.06 to $0.10 per foot ($0.24 to $0.40 for a four-foot tube).Ballast disposal costs depend on whether or not the ballasts have PCBs. The cost todispose of non-PCB ballasts ranges between $0.30 and $0.40 per pound, while the costto dispose of PCB ballasts ranges between $0.45 and $0.60 per pound. A typical two-lamp F40 ballast weighs about 3.5 lb. while a typical two-lamp F96 ballast weighs about7.0 lb.

Asbestos

Ceilings employing asbestos or building structures fireproofed with asbestos limit thepossibilities for the retrofitter because of the great cost of properly handling airborneasbestos fibers. Most of the time, all modifications will be made from below theluminaire without moving the luminaire from its grid location. If asbestos is notpresent, the retrofitter should also consider modifying the lighting layout as manyolder lighting designs had more luminaires than modern practice recommends.

Commissioning

Once the full audit is complete and retrofit options are selected and installed, it isextremely critical that the new components be calibrated and maintained properly.Occupancy sensors and dimmers are especially likely to perform under par ifincorrectly installed or calibrated.

Furthermore, if building engineers do not understand the new system they may findways to override or mis-calibrate it. The project’s energy savings and quality would notthen reach the expected potential. Training programs for building operating personnelare an essential part of a good commissioning plan. In addition, lighting maintenancecrews must become familiar with the new products installed and be alerted to thewarranty procedures for products that may subsequently fail.

Verification and Measurement

Once the retrofit measures are installed, measurement is often required on a periodicbasis to assure that the predicted savings are being achieved.


2-44

Verification of savings will find flaws in the predictions of the engineers. In manybuildings, for instance, the heat of the lighting system is used to heat the building. Ofcourse, mechanical heating (such as a furnace) is much more efficient, but in olderlighting technology, heat was a side benefit. There have been several lighting retrofitswhere the designer forgot to check on the heating capacity of the HVAC system and, aspart of the retrofit, to add heating capacity. The net result of this type of error is thatincreased heating costs erode the lighting savings. If employees respond by installingportable resistance space heaters, then the electric bill including demand charges mayactually go up. The theoretical lighting and HVAC savings are not achieved becausethe system lacks the heating capacity to prevent the employees' actions.

Ongoing operations of a building complicate matters. Changes in building occupancy,hours of operation, and process or office equipment can dramatically change thebuilding load. Without proper precautions, measurements can suggest lighting retrofitresults far different from actual occurrence.

In order to create an effective lighting verification program, the following steps arerecommended:

x Establish an accurate baseline. The baseline is critical. As accurately as possible,establish annual operating hours for every different schedule in the building.Measure only lighting loads whenever possible, avoiding especially receptacle andprocess load circuits. Measure unit loads to help make calculations more accurate.Account for burnouts and deferred maintenance as an adjustment to measuredvalues. Measure kWh and kW over as long and representative a period as possible.Account for seasonal variations as a further adjustment after measurements.Wherever possible, determine operating time using run time or time-of-use lightingloggers.

xx Establish a reasonable means to account for HVAC savings. For each unit oflighting energy savings, a building that is air conditioned will typically experiencean additional 10–30% of energy savings due to reduced loads on the HVAC system.These savings will be hard to measure and verify, since weather is the primaryvariable and obviously not repeatable for a monitoring period from year-to-year. Toaccount accurately for HVAC savings, install long-term measurement equipment onHVAC equipment, and collect annual data to document before-and-afterperformance.

x Verify lighting load changes as directly as possible. Immediately upon completionof the retrofit, measure lighting loads. Emphasize changes in adjusted kW demandfor luminaire retrofit projects and kW demand and kWh for controls retrofits. Takeextreme care that future measurements are taken for the same building area and atthe same point. Many buildings have 277/480 volt lighting systems and 120/208volt general receptacle and power systems, making this easier for the generalillumination fluorescent and HID systems; 120-volt lighting (usually incandescent)


2-45

is usually on independent circuits from plug load and other 120-volt loads. Ofcourse, many projects (especially smaller ones) will have mixed loads on the branchcircuits. In these cases, it is important to make certain that all loads have beenidentified and their presence (or absence) recorded during each measurement.

x Account for ongoing changes in the building's operation and occupancy.Surprisingly, this can be quite easy. If floor plans were obtained or available duringdesign, keep track of building plan changes. New walls or new tenants should beidentified on the plans on an ongoing basis. If plans were not obtained ordeveloped, make film or video records of the building and compare, if necessary, tothe owner's records of tenancy changes in the event of a dispute. Note thatconstruction can consume significant energy, and lights can get turned on even inunoccupied areas of the building. Operating hours can be remeasured with loggersif it appears a significant change occurred.

x Visually inspect for changes and "snap-back." Lighting different from the retrofitprogram will stand out and should be easy to identify. Although snap-back is a signof a problem in acceptance or retrofit maintenance cost, make a fair provision in theverification program to account for it.

xx Use each measurement program as a conservation study. Many times, additionalopportunities will become obvious during a follow-up review formeasurement/verification. Some opportunities not previously economically viablewill become worthwhile due to changes in operations, utility rate, and/or rebates.

Measured field data, in addition to the audit estimates, are an often overlooked yetextremely critical component of an accurate retrofit analysis. Using only the commonestimating techniques, errors as great as 25–40% of potential savings occur, usually dueto three problems. First, the energy actually used by a fluorescent system can differ by5–25% from the energy use figures that appear in manufacturers’ catalogues. Second,the actual hours that lighting systems operate are usually quite different fromsimplified assumptions. And third, the impact of the lighting load on the HVAC systemis often estimated incorrectly or completely omitted from the analysis.

Ongoing Maintenance

After a lighting retrofit, maintenance is almost eliminated for quite a while, saving theowner considerable expense. After that, proper maintenance of the lighting is essentialin preserving the energy efficiency of the lighting. Otherwise, lighting will be added ormodified in a manner unintended by the engineers and often to the point of ruining theenergy savings.

A term describing the most common undesirable phenomenon after the retrofit is snap-back, meaning that the installation will "snap back" to the previous condition. Snap-backis best prevented by using technologies which cannot easily be returned to the original


2-46

condition. For example, screw-in compact fluorescent lamps are generally notrecommended for commercial installations because after the life of the lamp or adapter(usually about 8,000 hours, or 1–2 years in commercial applications), the operator of thefacility will be forced to choose between a lower cost replacement (incandescent) andreplacing the aged fluorescent. Since this person often was not part of the originaldecision, he or she will be ill-informed of the benefits of compact fluorescent andenticed by the low cost of incandescent. Snap-back is virtually inevitable.

By following through with service and maintenance, the retrofitter helps prevent snap-back and other problems, such as:

x unnecessary or unwise expansion of track lighting systems

x use of higher-wattage replacement lamps

x use of lower-efficiency magnetic ballasts when electronic ballasts fail

x changes in operations resulting in greater energy cost

x minimizing maintenance errors, e.g. purchasing F40 lamps for replacement of T-8systems, encouraged by lower product cost and purchaser ignorance

x energy waste due to improperly installed, adjusted, or commissioned lighting andlighting controls

Other practical concerns are that the storehouse be alerted to begin eliminatingoutmoded products and stocking new equipment, and that electricians receive as-builtdrawings of areas with automatic lighting controls so that they do not waste timetrouble shooting a circuit that is open due to control malfunction.

3-1

3 RETROFIT TECHNOLOGIES

This chapter of the handbook outlines some of the most important technology changesthat can be incorporated in any lighting retrofit. Many of these technologies can be usedas simple unit replacements for failed or retired equipment or components, whileothers must be carefully planned and incorporated into a thoughtful lighting retrofitstrategy. Information in this chapter is organized in three sections: lamp/ballasttechnologies, luminaire technologies and control technologies. Chapter 4, LightingSystem Types, looks at retrofit opportunities as they relate to lighting system types. Forinstance, the retrofit opportunities for commercial troffers, a distinct lighting systemtype, are discussed. This chapter, on the other hand, presents generic information aboutthe basic technologies that may apply to more than one lighting system type such asswitching from T-12 fluorescents to the newer T-8 technology with electronic ballasts.

Lamp/Ballast Technologies

In the past five to ten years, lamp and ballast manufacturers have steadily improvedthe quality of their products, while introducing several successful new lamptechnologies. Many of these products are targeted for the retrofit market; as such, theyare designed to be energy-efficient alternatives to existing products. Most of theseproducts improve overall lighting quality as well as energy efficiency. Often these newlamps can replace existing, less efficient lamps on a simple socket for socket basis, withminimal labor charges for the relamping (though some strategies require a change inballasts, sockets or luminaires to accommodate the new lamps). Many effectiverelamping situations require no change in building wiring and no replacement ofluminaires or ballasts. Similarly, relamping does not create any significant newmaintenance issues other than that new lamp types must be purchased andwarehoused. As such, relamping can be a simple, effective, and cost-consciousretrofitting strategy. The important lamp technologies for the retrofit market are brieflydescribed in the following sections.

Relamping Retrofit Opportunities

This section presents some general considerations for relamping of existing lightingequipment. More details on each lamp ballast technology are presented in the sectionsthat follow. In general, relamping as a retrofit strategy should be limited toapplications when one or more of the following situations exists:

Retrofit Technologies

3-2

x There is a significant opportunity to save energy by using more efficacious lampsand by lowering HVAC costs.

x There is a need to increase the illuminance produced by a lighting system throughthe use of more efficient lamps and/or luminaires.

x There is an opportunity to reduce lighting levels.

x There are opportunities to replace existing lamps with products requiring lessmaintenance due to a longer effective operating lifetime.

x There is a desire or need to improve lighting quality through the use of lamps thatimprove color temperature and color rendering.

x There is a need to use new lamp technologies because of the provisions of theFederal Energy Policy Act or other standards or regulations.

Most relamping retrofit applications are fairly simple and straightforward: once theretrofitter has determined that relamping is an appropriate strategy to pursue, he (she)looks to increase the efficacy and lighting quality of the situation at hand. This goalmust be factored with the overall dollar amount of the cost premiums to be paid for therelamping and with the length of the payback period. Most relamping strategies have apayback period of less than three years, making relamping a very attractive retrofitlighting strategy. The following table illustrates some common lighting problems thatcan be resolved with appropriate relamping strategies:

Table 3-1Common Relamping Strategies

Situation Relamping Remedies

Correct Illumination Relamp with more efficacious light sources (e.g. replaceincandescent lamps with compact fluorescents)

Delamp (use reflectors, higher-output lamps, or higher-outputballasts to compensate for lost output)

Overlighted Spaces Delamp (Relamp with higher-output lamps if light levels are reducedtoo much)

Relamp with lower-output lamps

Underlighted Spaces Relamp with higher-output lamps, use reflectors, use higher-outputballasts

Excessive Lamp Failure Costs Relamp with longer-life lamps

Poor Lighting Quality—Color Rendition Relamp with high CRI sources

Poor Lighting Quality—Glare Usually not an appropriate option


3-3

Table 3-2Relamping Options

Existing Lamp Applications Appropriate Replacement(s) Performance Benefits

Incandescent "A" General & Down Lighting Compact FluorescentMetal Halide

Efficacy & Lamp LifeEfficiency, Efficacy, & LampLife

Incandescent Reflector Wall & Down Lighting Compact FluorescentHalogen PAR

Efficacy & Lamp LifeEfficiency & Efficacy

Incandescent Reflector Display Lighting Halogen IRCompact Metal Halide*

Efficiency & EfficacyEfficiency, Efficacy, & LampLife; Fewer Fixtures Required

F40T12 (Standard) General Lighting 32-34-watt F40T12/ESF40T12/REF40T10F32T8*

EfficiencyEfficiency, Efficacy, & CRIEfficiency, Efficacy, & CRIEfficacy & CRI

*Requires replacement luminaire socket and/or ballast

In most relamping retrofit strategies, the retrofitter will have more than one lampoption that will serve the purpose. There are at least two considerations that should beexamined in determining the retrofit lamp to choose. First, the ideal lamp replacementwill enhance lighting system performance on as many levels as possible (efficacy, CRI,lamp life, etc.). For instance, a lamp that provides both increased efficacy and longerlife may be a more desirable alternative than one which only increases efficacy. Table 3-shows some of the more common relamping options.

Another factor that the prudent retrofitter must consider when choosing amongdifferent relamping options is the relative payback periods of different relampingoptions. An expensive relamping strategy that requires 5–7 years to recapture the initialcost premium will probably not be as desirable as a relamping scheme that actuallysaves less energy, but pays for itself in under three years.

Lamp Performance Measures

There are several measures of lamp performance, including energy efficiency orefficacy, lamp life, lamp lumen depreciation (LLD), and color, that are important inmaking retrofit decisions that involve lamp replacements. In general, relampingstrategies should substitute lamps that have better performance than the lamps theyreplace in as many areas as possible. Table 3- shows the typical performance ofdifferent types of lamps. More detail is provided in the text that follows.


3-4

Table 3-3Performance Characteristics of Various Light Sources

Lamp Type Efficacy*(Lumens/ Watt)

Average Life (Hours) Lamp LumenDepreciation(LLD)

Correlated ColorTemperature(CCT) (°K)

ColorRenderingIndex (CRI)

Standard Incandescent 5–20 750–3,000 High 2,800 100

Tungsten Halogen 15–30 2,000–4,000 Low 3,000 100

Halogen Infrared Reflecting 20–30 2,000–3,000 Low 3,000 100

Mercury Vapor 30–60 12,000–24,000 High 3,300–5,700 15–50

Compact Fluorescent (5–26 Watts) 20–85 9,000–12,000 Low 2,700–5,000 80

Compact Fluorescent (27–40 Watts) 50–80 15,000–20,000 Low 2,700–5,000 80

Full–Size Fluorescent 60–90 15,000–24,000 Medium 2,700–7,500 50–90

Metal Halide (175–1500 Watts) 45–100 3,000–20,000 High 3,000–6,500 65–85

Compact Metal Halide (32–150 Watts) 45–80 2,000–20,000 High 3,200–6,500 60-90

High Pressure Sodium 45–130 16,000–24,000 Low 2,100–2,200 22

Deluxe and White Sodium 35–55 10,000–15,000 Medium to High 2,200–2,800 65–80+

*Note: Lumens per watt values include ballast; all values are for most commonly used lamps and are approximate. See the 1993Advanced Lighting Guidelines for specific values.

Figure 3-1 Lighting Source Efficacies


3-5

Energy Efficiency

Efficacy is the common term for the energy efficiency of lamps. Efficacy is the ratio ofthe light produced by the lamp (in lumens) to the rate of energy used by the lamp (inwatts). The least efficacious lamps have an efficacy of less than 10 lumens/watt, whilethe most efficient lamps have an efficacy of more than 100 lumens/watt. The efficacyrange can be quite large for a particular lamp type depending on its size (wattage), thetype of ballast and other features. Data on typical lamp efficacies are presented in Table3-. Figure 3-1 shows the typical range for each lamp type.

In addition to producing visible light, lamps produce heat. High efficacy lampsproduce less heat than the less energy-efficient products they replace. In some cases,this heat production is quite extreme. Some incandescent lamps, for instance, convertup to 90% of the power they receive into heat. Less than 10% of the input power isconverted to visible light. Efficacious lamps are able to reduce this ratio considerably,contributing to significantly reduced air conditioning loads and more comfortableconditions.

When determining the efficacy of any lamp under consideration for retrofitting, it isimportant to include consideration of the ballast and the luminaire. The ballast is anintegral part of the source system that cannot be ignored. The effect of the luminaire ismore subtle and fluorescent luminaire performance is related to the bulb-walltemperature of the lamps. Closed luminaires (those with lenses) operate at a highertemperature than open luminaires (those with open parabolic reflectors). Similarly,four-lamp troffers operate at a higher temperature than two-lamp troffers. In general,the higher the temperature, the less efficient the lamp; but this is not always true. Formore information, see the chapter on luminaires and lighting systems in the 1993Advanced Lighting Guidelines, TR# 101022, R1 available from EPRI. Incandescent andHID luminaire performance is not affected by ambient temperature.

Lamp Life

Lamp life (in hours of operation) is another measure of performance. Lamp life ratingsare determined under ANSI conditions (open air, 25°C [77°F]) at three operating hoursper start for fluorescent and 10 hours of operation per start for HID lamps. Effectivelamp life may be adversely affected by more frequent switching. Similarly, rated lamplife is generally increased by average operating times of more than three hours perstart. Maintenance costs for relamping are reduced by employing lamps with longoperating lives. As such, the ideal retrofit relamping strategy would provide productswith extended operating lives whenever possible. See Table 3- for typical lamp lives.


3-6

Lamp Lumen Depreciation (LLD)

The light output of most light sources decreases with accumulated hours of operation.Thus, lamps that are near the end of their lives may produce significantly less light thannew lamps. Different lamp technologies have significantly different rates of lumendepreciation. For instance, standard incandescent lamps depreciate noticeably as theyage, due to a gradual boiling away of the tungsten filament. Filament particleseventually deposit on the lamp’s bulb wall, effectively blocking much of the lamp'slumen output, which has already been reduced due to the smaller diameter of thefilament. Modern tungsten halogen lamps, by contrast, show very little lumendepreciation over lamp life, as their design is such that evaporated tungsten moleculesare caused to redeposit onto the lamp filament. Lamp lumen depreciation for somehigh intensity discharge (HID) lamps is considerable, as much as 50%. Consideration ofthe extreme LLD of these HID lamps can result in recommendations to replace thesource with fluorescent. Even though the fluorescent lamp may be less efficacious interms of initial lumens, it is a more efficient source for the life of the lamp.

Color Rendering Index (CRI)

The color rendering index (CRI) of a lamp describes the degree of color shift thatobjects undergo when illuminated by the light source under consideration, ascompared to their color appearance under a reference source of the same colortemperature. CRI is measured on a scale up to 100. Incandescent lamps are thereference (below 5000K) and have a CRI of 100 (by definition). For lamps with colortemperatures above 5000K, daylight is reference and has a CRI of 100 (by definition).The CRI for standard halophosphor fluorescent lamps is substantially lower (typically,around 55–60). Table 3- gives a CRI range for common lamp types while Table 3- showsthe typical CRI range and gives some examples of lamps in each range. Many of theenergy-efficient advances in lamp technologies have also improved color rendering. Asa result, most retrofits will not only improve energy efficiency, they will also improvethe lamp’s color rendering ability.


3-7

Table 3-4Color Rendering

Lamp Quality Color Rendering Index

High-Pressure Sodium Poor 22

Deluxe Mercury Vapor Poor 50

Warm White Fluorescent Fair 53

Cool White Fluorescent Fair 62

Clear Metal Halide Fair 65

Rare Earth Fluorescent Good–Excellent 70–85

Deluxe Metal Halide Excellent 80–90

Special Fluorescent Excellent 92

Incandescent or Sunlight Reference 100

Table 3-5Color Temperature

Correlated Color Temperature Lamp Types Ambiance

2100 K High-pressure sodium Very warm

2500–3200 K IncandescentsWarm fluorescents

Warm

3400–4300 K Cool and white fluorescentMost metal halides

Neutral to cool

4500–7500 K “Daylight” fluorescentCool metal halide

Cool to blue

Correlated Color Temperature (CCT)

The correlated color temperature (CCT) of a light source is the apparent color of lightproduced by that source. CCT is measured in Kelvins (K). Technically, the CCT is thetemperature of a black body radiator that has the same apparent color. Most electriclamps produce light with a CCT between about 2000K and 8000K. In an odd play ofterminology, lower temperatures produce a warmer ambiance and higher temperaturesproduce a cooler ambiance. Table 3-5 illustrates the range of color temperatures andgives examples of lamps that operate in each range. Lamps with temperatures of 4100Kand above produce a light that is bluish-white in appearance (cool), while lamps withtemperatures of 3000K and below produce a warmer light. For further information,consult The Lighting Fundamentals Handbook, TR-101710 available from EPRI.


3-8

With efficacy, color rendering index, and lamp life, more is always better. This is notthe case, however, with color temperature. Sensitive designers will carefully select thecolor temperature of lamps to create the desired ambiance and mood. Sometimes awarm ambiance is desired, for instance in hotel lobbies. Sometimes a cool ambiance isdesired, for instance in manufacturing plants. The development of energy-efficientlamp technologies has expanded the designers’ capabilities by extending the colortemperature range of most lamps.

Lamp Efficiency and Energy Legislation

The Energy Policy Act of 1992 was passed by the 102nd Congress and signed into lawby former President Bush on October 24, 1992. The Act is an amendment to the 1975Federal Energy Policy and Conservation Act, and has profound implications for thelighting retrofit market. The Act establishes minimum efficiency standards for manytypes of electric lamps. Targeted lamps not meeting required efficiency standardscannot be manufactured or imported for sale in the United States. The Energy PolicyAct also calls for lamp labeling. Lamps will be labeled so that users may choose themost energy-efficient lamps available.

Efficiency Standards

The current provisions of the 1992 Energy Policy Act assign efficiency standards topopular versions of full-sized fluorescent and R and PAR-type incandescent reflectorlamps. The Act may be amended at a later date to extend the standards to other lamptechnologies and configurations.

Table 3-6Energy Policy Act Requirements for Full-Size Fluorescent Lamps

Lamp Type NominalLampWattage

MinimumCRI

Minimum AverageEfficacy (LPW)

4-foot Med. Bi-Pin !35d35

6945

75.075.0

2-foot U-shaped !35d35

6945

68.064.0

8-foot Slimline 65d65

6945

80.080.0

8-foot High Output !100d100

6945

80.080.0


3-9

Table 3-7Energy Policy Act Requirements for Incandescent Reflector Lamps

Nominal Lamp Wattage Minimum Average Efficacy(LPW)

40–50 10.5

51–66 11.0

67–85 12.5

86–115 14.0

116–155 14.5

156–205 15.0

Full-Size Fluorescent Lamps. The Energy Policy Act is having a profound effect on theuse of full-size fluorescent lamps. Lamp efficiency standards apply to the most commonlamps used in commercial output lamps. To comply with the efficiency standards,lamps must meet the minimum efficacy and CRI values shown in the table.

The most significant effect of the Energy Policy Act on fluorescent lamps is that it willeliminate the manufacture and importation of most full-wattage (non-energy saving)halophosphor cool white and warm white lamps. This will encourage the use of high-CRI RE lamps, producing significant improvements in energy efficiency and lightingquality in standard commercial lighting installations.

Fluorescent lamps exempt from the efficiency standards of the Energy Policy Actinclude colored lamps, ultraviolet, high-CRI halophosphor, cold temperature, and plantgrowth lamps. The efficiency standards took effect April 30, 1994, for 8-foot lamps andOctober 31, 1995, for 4-foot and U-shaped lamps.

Incandescent Reflector Lamps. Lamp efficiency standards of the Energy Policy Act willalso apply to medium-based incandescent R and PAR-type reflector lamps, 115–130volt, 40–205 watts, with a diameter greater than 2¾" (R/PAR-22). The standard forthese lamps became effective October 31, 1995, and it is likely to eliminate the use ofmany non-halogen incandescent R and PAR lamps. Reflector lamps that will be exemptfrom compliance include ER (elliptical reflector) lamps, colored lamps, rough servicelamps, and R20/PAR20 lamps. Non-exempt incandescent reflector lamps must meetminimum efficacy levels, relative to lamp wattage, as listed.

The new efficiency standards for R and PAR-shaped incandescent reflector lamps willeffectively eliminate the manufacture and importation of a large number of extremelypopular lamps. Specific examples include R-30 and R-40 reflectors as well as all non-halogen PAR-38 lamps. “BR” lamps are exempt, and some classic designs arereincarnated as more efficacious, shorter-life types.


3-10

Lamp Efficiency Labeling

The Energy Policy Act of 1992 also requires that the Federal Trade Commission (FTC)establish lamp labeling rules that will allow users to select the most energy-efficientlamps that meet their respective application requirements. There are four lampcategories that are affected:x medium-based general service incandescent lamps, 115–130 volts, 30 watts and

above

x R and PAR incandescent reflector lamps 115–130 volts, 40 watts and above, largerthan R-22 (2¾") in diameter

x medium-based (self-ballasted) compact fluorescent lamps

x full-size T-8 and T-12 fluorescent lamps

There are several products in each category that are exempt from the labelingrequirements. Most of the exempted lamps are decorative or serve a special purpose.

Additional Requirements

The U. S. Department of Energy (DOE) will be in charge of evaluating the newefficiency standards for fluorescent and incandescent reflector lamps. DOE willdetermine if these standards should be amended. The Energy Policy Act also directsDOE to examine the feasibility of establishing efficiency standards for HID lamps. Inaddition, DOE is charged with evaluating the need for efficiency standards for otherlamp types not covered by the Act. In addition to standards on lamps and ballasts, theEnergy Policy Act requires that states update their building energy efficiency standardsto be at least as stringent as ASHRAE/IESNA Standard 90.1—1989.


3-11

Figure 3-2 Tungsten Halogen Lamp Sizes


3-12

Tungsten Halogen Lamps

Though only slightly more efficacious than standard incandescent lamps, tungstenhalogen lamps are nonetheless valuable, inexpensive retrofitting options for manyincandescent applications. These lamps are filled with a halogen gas that suppressesdegradation of the tungsten filament. Lamp design allows for filament configurationsthat produce a brilliant white light with higher efficacy and longer life than traditionalincandescent lamps.

In most cases, lamps replace standard incandescent lamps without a change in wiringor lamp socket. Ideally, they should be used only in situations where a change to amore efficacious lamp technology (such as fluorescent) would adversely affect designgoals. Appropriate applications for lamps might include highlighting of art work,display lighting for merchandising, or other cases where a point source of illuminationwith full-range dimming and high color rendering is required. Tungsten halogen lampsare available in several configurations. Two of the most important for retrofitapplications are described below:

PAR Capsule Lamps

PAR capsule lamps consist of a halogen "bud" surrounded by an outer PAR (parabolicaluminized reflector) envelope. Configurations include PAR-16, PAR-20, PAR-30, andPAR-38. These lamps are designed for accent lighting applications, such as displaylighting of merchandise. They can replace standard reflector lamps with a significantreduction in lamp wattage. Nevertheless, they are only slightly more efficacious thanstandard incandescent lamps.

Infrared-Reflecting Lamps

Infrared-reflecting (IR) lamps have ushered in a new era in retail display lighting. A 60-watt PAR IR lamp can replace a 150-watt standard PAR incandescent lamp, with noloss in illuminance level or lighting quality. IR lamps are especially suitable as retrofitreplacements for incandescent track and recessed down lighting. While they still arenot nearly as efficacious as other advanced lamp technologies, they do allow forsignificant reductions in lighting power in retrofit applications. They are available inmedium-based PAR envelopes, as well as double-ended, high-wattage quartz lamps.


3-13

Figure 3-3 Infrared-Reflecting Technology

Compact Fluorescent Lamps

Compact fluorescent lamps were originally designed as an energy-efficient retrofitalternative to standard incandescent lamps. Generally, compact fluorescent lampsconsume only one-third to one-fourth the energy of their incandescent counterparts,and they last up to 10 times longer. Many are equipped with screw-in, medium-basesocket adapters that enable a direct lamp-for-lamp replacement in existing incandescentluminaires. Compact fluorescent lamps are available in several shapes and sizes,including twin-tube, quad-tube, and multiple-tube configurations. Wattages generallyrange from 5 to 27.

There are two basic compact fluorescent lamp-ballast configurations that are especiallyapplicable for retrofit situations:

x Medium-base self-ballasted screw-in compact fluorescent lamps are designed to replaceexisting incandescent lamps on a socket-by-socket basis. Integral self-ballasted lampsare one piece lamp-ballast units. They are increasingly available with electronicballasts. These units require that the ballast be replaced along with the lamp whenrelamping. Modular self-ballasted compact fluorescent lamps, on the other hand,feature a lamp that detaches from the screw-in ballast, allowing for simplereplacement of only the lamp at relamping time.


3-14

x Dedicated compact fluorescent units are designed for permanent retrofitting of existingincandescent luminaires. Typically they consist of a hardwire conversion unit,ballast, and single or double socket with detachable lamp(s). They can be designedto use nearly any lamp configuration. Once installed, they allow for simple lampreplacement exclusive of the ballast.

Figure 3-4 Typical Screw-In Compact Fluorescent Lamps

Self-ballasted compact fluorescent lamps are readily available with electronic ballasts.Both the twin-tube and quad-tube compact fluorescent lamps are now available withsingle-ended four-pin bases, which allow for the removal of the integral starter andfacilitates their use with rapid-start electronic ballasts. This is a promisingdevelopment, as the use of these lamps with electronic ballasts should result in evengreater energy efficiency while increasing occupant satisfaction by reducing noise,starting time, and lamp flicker.


3-15

In the past, many electronic ballasts for compact fluorescents have introducedunacceptably high levels of total harmonic distortion (THD) into building powersystems. The situation is improving, but the retrofitter should nevertheless try to avoidthe use of products with high THD. THD is reported in most literature provided bylamp manufacturers.

Figure 3-5 Typical Dedicated Compact Fluorescent Lamps

The socket adapters included in self-ballasted compact fluorescent lamp packagesallow for easy and inexpensive relamping of incandescent luminaires. As a result,compact fluorescent lamps have enjoyed popularity as an incandescent retrofit ineverything from recessed down lights to floor and table lamps. Nevertheless, this typeof perfunctory retrofit strategy has severe limitations.

x First, in retrofit applications, the problem with any screw-in compact fluorescentadapter is that it is not a permanent conversion. Relamping with incandescentlamps at lamp maintenance intervals is a distinct possibility.

x Another common problem produced by the use of compact fluorescent lamppackages is that the screw-in lamp-ballast assemblies often are incompatible withthe existing design of the luminaires being retrofitted. The result is that luminairephotometrics are compromised, and the overall appearance of the luminaire may beobjectionable.

Fortunately, some manufacturers are now offering compact fluorescent productsdesigned to make the conversion from incandescent to compact fluorescent much morepermanent and more congruent with luminaire design. Some of these products use


3-16

adapters with added reflectors to improve photometrics, while others are hardwireddirectly into the luminaire itself.

Figure 3-6 Typical Compact Fluorescent Conversion Kit

Overall, compact fluorescent lamps offer substantial energy savings over traditionalincandescent lamps. Replacement of incandescent lamps with equivalent outputcompact fluorescents can produce energy savings of 60% to 75% and increase lamp lifeby a factor of 10.

Full-Size Fluorescent Lamps

During the past ten years lamp manufacturers have substantially improved theperformance characteristics of full-size fluorescent lamps. The use of high output, highcolor-rendering rare earth (RE) phosphors along with the development andmanufacture of T-8, T-10 and T-5 twin-tube lamp envelopes has increased theopportunities for increased energy efficiency and lighting quality in retrofit lightingdesign. Several energy-efficient lamp products are now available that allow for theretrofitting of standard F40T12 lamps with more advanced products.

Direct Retrofits for F40T12 Halophosphor Lamps

The following full-size fluorescent lamps may be used to retrofit standard F40T12lamps on a lamp-for-lamp basis (no change in ballast is required). All of these lampswill provide better energy efficiency, and most will improve color rendering. Inaddition, most of these lamps have less lamp lumen depreciation and may haveextended lamp life.


3-17

x Rare earth phosphor (RE) T-12 lamps utilize rare earth phosphors to produce up to 5%more light and increase CRI substantially over standard T-12 lamps. Rare earthphosphors are now available for virtually every type of fluorescent lamp, includingU-Bent lamps. The RE phosphor coating is standard in all advanced products, suchas compact fluorescents, T-10s and T-8s.

x T-10 lamps also utilize rare earth phosphors. While they draw more power thanstandard F40 lamps (42 watts to 40 watts), they also increase lumen output by 21%,lamp life by 20%, and color rendering by 42%. They are especially appropriate inapplications where a standard T-12 delamping strategy might reduce light levels toomuch. For example, a four-lamp T-12 fixture can in many cases be retrofitted withtwo or three F40T10 lamps without too great a drop in overall luminaire output. T-10 lamps are also useful in many applications where task areas are severelyunderlighted. They allow for a significant increase in lumen output without theneed for new luminaires or ballasts.

x Extended output T-12 lamps are also valuable in delamping strategies andunderlighted applications. They generate 7–9% more light output and increase lamplife 20% over standard F40 lamps.

x Energy saving (ES) lamps draw less wattage than full light output T-12 lamps. ESlamps are available in F40, and F96 slimline and high output configurations andwith RE or standard halophosphors. Since ES lamps produce fewer lumens thanstandard T-12 lamps, their best retrofit application is in overlighted spaces. ESlamps should not be used for dimming applications, and they are more sensitive tolower temperatures than standard T-12 lamps.

x Heater cutout lamps are ES lamps that save an additional 2½ watts by disconnectingthe lamp heater filament after the initial starting discharge (there are also ballaststhat perform this operation). Their performance is similar to that of ES lamps, andthe same restrictions apply.


3-18

Figure 3-7 Typical Diameters of Full-Sized Fluorescent Lamps

Lamps

Other advanced fluorescent lamp products have substantially increased performancecharacteristics when compared with standard T-12 lamps. Not all of these products arepractical for most retrofitting purposes, however, since they will require—at the veryleast—a change in ballasts. Some of these products, such as T-5 twin-tube lamps, alsorequire changing lamp sockets or luminaires, as well, effectively eliminating them frommost retrofitting strategies. For these reasons, this discussion is limited to a descriptionof T-8 265 mA lamps.

T-8 lamps operate at 265 mA current. As such, they require special ballasts, thoughtheir bases (bi-pin or slimline) will fit the same sockets as corresponding T-12 lamps.These lamps are available in U-bent configurations and in straight tubes up to 8 feetlong. Wattages range from 16 to 59.

A 4-foot F32T8 produces nearly the same initial lamp lumens as a standard F40T12, butdraws only 32 watts (not including ballast). F32 lamps may be linked with instant-startelectronic ballasts to achieve an efficacy of nearly 90 lumens per watt. By comparison,the maximum efficacy of an electronically-ballasted F40T12 system is less than 80lumens per watt.


3-19

The newest members of the T-8 lamp family are the F96T8 single pin lamp, introducedin 1992 and the F96T8/HO introduced in 1994. They are designed for electronic ballastoperation and will compete with the popular F96T12 slimline lamps. The T-8 lampproduces similar light output as the energy savings version of the T-12 counterpart, butsystem efficacy increases to more than 90 lumens per watt. In addition, electronically-ballasted F96T8 and F96T8/HO lamps have a rated lamp life of 15,000 hours at 3hours/start. Most of the improved performance is attributed to the use of electronicballasts.

T-8 lamps are smaller in diameter than traditional T-12 lamps (1" to 1½"), and can beused in smaller luminaire enclosures. In addition, the small size of the T-8 lamp oftenserves to increase luminaire efficiency due to lower light loss factors.

T-8 lamps generally make good sense in most retrofit applications where a change inthe existing ballasts is also being considered. On a life-cycle cost basis, the T-8 lamp-ballast system is generally a better investment than any T-12 system, particularly ifelectronic ballasts are also installed. However, if the existing ballasts are the energy-efficient type in good condition, it can be a more cost-effective strategy to relamp withenergy-efficient T-12 or T-10 lamps if utility rates are low.

A comparison of advanced technology full-size fluorescent lamp characteristics is listedas follows.


3-20

Table 3-8Fluorescent Lamp Characteristics—Common 4-foot lamps1

Lamp Type Input watts for 2 lamps andballast

Lumen output for apair of lamps

Efficacy(lumens perwatt)

CRI

F40T12CW (pre-1995)

40 watt

3050 lumens

(Mag Std) 92

(Mag EE) 86

(Elec RS) 78

5,612

5,612

5,307

61

65

68

62

F40T12RE70

40 watt

3200 lumens

(Mag Std) 92

(Mag EE) 86

(Elec RS) 80

5,796

5,796

5,481

63

67

70

724

F40T12RE80

40 watt

3300 lumens

(Mag Std) 92

(Mag EE) 86

(Elec RS) 80

5,980

5,980

5,655

65

69

72

82

F40T12/ES/CW

34 watt

2700 lumens

(Mag Std) 80

(Mag EE) 72

(Elec RS) 682

4,915

4,915

4,802

61

68

71

62

F40T12/ES/RE70

34 watt

2800 lumens

(Mag Std) 80

(Mag EE) 72

(Elec RS) 68

5,092

5,092

4,975

63

71

74

724

F40T12/ES/RE80

34 watt

2900 lumens

(Mag Std) 80

(Mag EE) 72

(Elec RS) 682

5,272

5,272

5,151

66

73

76

824

F40T10/RE80

40 watt (rated) 42 watt (actual)

3700 lumens

(Mag Std) 94

(Mag EE) 88

(Elec RS) 80

6,808

6,808

6,475

72

77

81

85

F40T12/ES+/RE70

32 watt

2650 lumen

(Mag Std) 76

(Mag EE) 86

4,888

4,888

64

72

724

F32T8/RE70

32 watt

2800 lumens

(Mag EE) 70

(Mag HC) 66

(Elec RS) 62

(Elec IS) 59

5,270

5,270

5,175

5,155

75

76

83

87

75

F32T8/RE80

32 watt

2950 lumens

(Mag EE) 70

(Mag HC) 66

(Elec RS) 62

(Elec RS—High output) 84

(Elec RS—Low output) 52

(Elec IS) 59

5,428

5,210

5,332

7,5523

4,602

5,310

77

79

86

90

89

90

824

F25T12/RE70 (T8 ballast)

25 watt, 2300 lumens

(Elec RS) 48

(Elec IS) 46

4,048

4,048

84

88

724

FM28LW (HC only)


(Mag HC) 60 4,210 70 49

F28T5


(Elec RS) 54 5,075 94 85

NOTES

1 Laboratory test conditions; actual wattage and lumens are ofter lower because of thermal effects.

2 The use of 34-watt “energy saving” lamps on electronic ballasts designed for T-12 lamps is not recommended due to lamp lifeproblems and other considerations

3 Different manufacturers’ products utilize various ballast factors and input watts. This is the highest value.

4 Color rendering varies depending on CCT. Generally values range from 70 to 82.


3-21

Table 3-9Fluorescent Lamp Characteristics—Common 8-foot lamps

Lamp Type Input watts for 2 lamps and ballast Lumen output for a pairof lamps

Efficacy(lumens perwatt)

CRI

F96T12CW (pre-1995)75 watt (Slimline)6250 lumens

(Mag Std) 172(Mag EE) 158(Elec IS) 130

11,18011,18011,050

657185

62

F96T12RE7075 watt (Slimline)6500 lumens

(Mag Std)172(Mag EE) 158(Elec IS) 130

11,51511,51511,382

677387

72

F96T12RE8075 watt (Slimline)6800 lumens


11,86011,86011,723

697589

82

F96T12/ES/CW60 watt (Slimline)5500 lumens


9,1359,1358,925

687485

62

F96T12/ES/RE7060 watt (Slimline)5700 lumens


9,4099,4099,192

707687

72

F96T12/ES/RE8060 watt (Slimline)6000 lumens

(Mag Std) 135(Mag EE) 123(Elec IS)105

9,6919,6919,467

727889

82

F96T12/HO/CW (pre-1995)110 watt8800 lumens

(Mag Std) 252(Mag EE) 237(Elec RS) 190

15,63215,63214,365

626676

62

F96T12/HO/RE70110 watt9200 lumens


16,10016,10015,075

646878

72



16,58516,58515,530

667080

82

F96T12/HO/ES/CW95 watt8000 lumens


13,74613,74612,480

626678

62

F96T12/HO/ES/RE7095 watt8350 lumens


14,15514,15512,860

646880

72

F96T12/HO/ES/RE8095 watt8500 lumens


14,58014,58013,245

667082

82

F96T8/RE7059 watt5800 lumens

(Elec IS) 105 9,230 88 75

F96T8/RE8059 watt5950 lumens

(Elec IS) 105 9,510 91 85


(Elec RS) 160 13,550 85 75


(Elec RS) 160 13,960 87 85


3-22

Other Fluorescent Technologies

Significant advances in fluorescent lighting technology have resulted in several majorinnovations. The more important include:

x Low-mercury fluorescent lamps Until a lamp using totally non-toxic technology isdeveloped, fluorescent lamps will continue to serve as the mainstay for mostcommercial lighting. Recent advances in mercury dosing technology assure thatlamps receive only the very smallest amount of it — and in turn, pass the EPA’sToxic Characteristic Leaching Procedure (TCLP) test for hazardous waste. Thismanufacturing process is being applied to 34-watt T-12 lamps as of 1996, and lampsbearing the distinctive green end band (or otherwise marked) can be discarded asnon-hazardous waste when they fail.

x Smaller-diameter T-5 straight lamps Probably the last reduction in lamp diameterfor full-size lamps, the T-5 lamp increases the efficacy over T-8 lamps, generatingmore light per watt than any other general lighting fluorescent lamp. Technicallimitations to the manufacture and operation of small diameter lamps have beenovercome, although concerns over source brightness will limit applications andcontinue to assure the viability of the T-8 lamp as the mainstream lamp of thefuture. Straight T-5 lamps are not 4 ft long. Further restricting retrofit applications.

x Even smaller diameter T-2 lamps Although the lamps are too delicate for longtubes, small diameter lamps up to 20” long have been introduced and are expectedto play a major role in making energy-efficient specialty lighting applications.

Among these, the low-mercury lamps are expected to play a major role in retrofitting,while the smaller- diameter lamps will be useful in certain applications.

High-Intensity Discharge Lamps

Lighting systems using high-intensity discharge (HID) lamps are common in a varietyof interior and exterior commercial and industrial applications. Improvements inenergy efficiency for HID systems are often harder to identify and implement, in largepart due to the inherently high efficacy of modern HID systems. However, recenttechnology improvements present new concepts and opportunities in HID systemsretrofitting with a surprising number of applications.


3-23

Figure 3-8 High-Intensity Discharge Lamp Technology

With HID lamps, a high-temperature, high-pressure arc is created in a small “arc tube”having inert gases and metals that become vaporized once the lamp is operating. Thearc tube is enclosed within a more conventional hard glass bulb. The material of the arctube and the tube’s internal chemicals determine the type of lamp and itscharacteristics. The outer bulb may be clear, diffuse-coated to distribute and soften theintense arc, or phosphor-coated to both diffuse the arc and modify the lamp color.Generally, clear lamps are used in luminaires which have high performance orprecision optics, and coated lamps are used in less demanding luminaires. This isespecially important in retrofitting.

Current through the lamp is regulated by a ballast, of which there are several differenttypes. The initial arc of the lamp is started by an ignition circuit that may be internal tothe lamp, integral to the ballast, or external to both. All HID lamps share thecharacteristics of:

xx Warm-up time, a period ranging from 90 seconds to 5 minutes, during whichpressure and temperature build within the arc tube until nominal lamp operation isachieved.

x Re-strike time, a period ranging from a few seconds to 10 minutes after the lamp isextinguished (usually accidentally or due to a power outage, even a short one),during which the arc tube must cool after being operated until the arc can be re-


3-24

ignited. Hot or instant-restrike lamps and special ignitors exist but cost andcomplexity make them rare and limit applications to critical situations.

There are four major families of HID lamps, each with specific technical qualities andcomponents that are generally NOT shared with any other HID lamp family.

x Mercury vapor. Mercury vapor lamps are one of the oldest HID technologies. Thearc tube is typically made of quartz glass, and the arc causes mercury vapors to emitvisible and UV light. There is a wide range of lamp wattages and shapes. Mercuryvapor lamps have long life, poor lumen maintenance, medium efficacy and poor tofair color. Most mercury vapor lamps are phosphor coated to improve the color.

x Metal halide. Metal halide lamps were developed in the mid-1960s as an alternativeto mercury vapor. The arc tube is similar and in addition to mercury vapor, othermetals’ vapors (such an indium, thallium, sodium, and dysprosium) radiate otherparts of the spectrum. The result is a family of lamps with good to excellent color,high efficacy, and medium-to-long life. Metal halide lamps have a number ofapplication considerations, such as position sensitivity and comparatively fairlumen maintenance, that make them a bit harder to apply with consistent results.Recent developments in metal halide, including the use of a ceramic arc tube andnew ballasts (see below) are expected to make even bigger improvements in metalhalide applicability.

x High-pressure sodium (HPS). HPS lamps typically utilize a ceramic arc tube andrely principally upon the spectrum emitted by vapors of sodium to create ayellowish-white light. HPS lamps have extremely long life and high lumenmaintenance. Variations on high-pressure sodium include so-called “white” sodiumlamps which have significantly improved color while sacrificing some of the moredesirable qualities such as length of lamp life. The importance of HPS in streetlighting is tremendous, and special products like a double arc-tube lamp (instantrestrike, extremely long life) are made especially for this application.

Low-pressure sodium (LPS). With LPS lamps, the arc operates at lower temperature,and is therefore noticeably longer and less compact than HPS. But because of its warm-up characteristics, LPS is generally considered an HID lamp. The spectrum emitted ismonochromatic yellow, making illuminated colors indistinguishable. Extremely highefficacy, long life, and excellent lumen maintenance make these lamps technicallyappealing, although the seriously deficient color limits applications considerably.

Table 3-10Properties of HID Lamps

Quality Mercury Vapor Metal Halide High-PressureSodium

Low-Pressure Sodium

Bulb shapes A, BT, E, ED, R, PAR,others

BT, E, ED, R, PAR, T,others

E, ED, R, PAR, T,others

T only

Sockets Medium ceramic; mogulceramic

Medium ceramic pulserated; mogul ceramic;

Medium ceramic pulserated; mogul ceramic

special twin-post


3-25

recessed single contactceramic; Others: Specialsocket for lamps notrequiring protective lenscover; Special socket forposition-oriented lamps

pulse rated; recessedsingle contact ceramic;others

Wattages 50, 70, 100, 175, 250,400, 1000

32, 35, 50, 70, 100, 150,175, 250, 325, 360, 400,650, 700, 950, 1000, 1500,2000

35, 50, 70, 100, 150,200, 250, 400, 1000and others

18, 35, 70, 100, 135,180

Ballast types Linear reactor NPF;linear reactor HPF;constant wattageautotransformer (CWA);auto-regulator

Linear reactor HPF;constant wattageautotransformer; auto-regulator; lead-peaked auto-reg; electronic; DCelectronic; hybrid

Linear reactor NPF;linear reactor HPF;constant wattageautotransformer;electronic; DCelectronic

Linear reactor HPF;constant wattageautotransformer

Ignitors Internal to lamp Internal to lamp (175-wattmin.); internal to ballast orexternal to both (allwattages)

Internal to ballast orlamp or external toboth

Internal to ballast

Color Clear: 4700K, 10 CRIDX: 4100K, 50 CRIWDX: 3300K, 50 CRI/N: 3300K, 65 CRI

Standard clear: 4100K, 65CRI Standard coated:3700K, 70 CRI Warm clear:3200K, 65 CRI Warmcoated: 3000K, 70 CRI HQIclear: 3000K, 85 CRI or4100K, 85 CRI Ceramic arctube clear and coated:3000K, 85 CRI. Other typesexist for specialapplications; saturatedcolors available

Standard clear andcoated: 2100K, 22CRI Deluxe clear andcoated: 2200K, 65 CRI“White”: 2500-2800K,70-85 CRI

1800K no color rendition

Luminous Efficacy(initial)

25 to 60 LPW 50 to 110 LPW 35 to 140 LPW 80 to 140 LPW

Retrofit Opportunities Replace with high-wattage compactfluorescent, metal halide,or high-pressure sodium

(1) Replace low-wattageunits with high-wattagecompact fluorescent; (2)Replace standard lampswith reduced watt versions(3) Change ballast to moreenergy-efficient version; (4)Install self-protected lamp,eliminate lens to improveLDD factor

None recommended None recommended


3-26

Ballasts for HID Lamps

Conventional “magnetic” HID ballasts can be complex devices with several functions.When retrofitting a luminaire, the electrician is often faced with several discretecomponents in a “core and coil” arrangement, which in fact is the core-and-coilassembly and one or more other components. Encased ballasts generally include:

x the actual ballast, generally a winding (coil) on an iron transformer core that mightalso be shared with other windings

x a transformer, also consisting of winding(s) on the core which adjust the buildinginput voltage to match the lamp open-circuit voltage

x a capacitor for power-factor correction

x an ignitor and/or other specialized electronics

There are an increasing number of electronic ballasts for HID lamps. Electronic ballastsgenerally cannot realize the same types of savings for HID lamps as they do forfluorescent. This is in part because high-frequency operation offers no advantages(other than size and weight) for HID lighting, and in part because many HID lampscannot be operated at high-frequency lest they experience mechanical resonance andexplode. However, a major advantage of the electronic ballast is reduced size andweight as compared to magnetic ballasts. Current products include 60 Hz, high-frequency and DC lamp operation.

Electronic ballasts are standard for a few HID lamp types and offer a slight increase inefficiency. But the real promise of HID electronic ballasts, especially for metal halide, isimproved lamp management over life, making lamp color more consistent, decreasinglumen depreciation, and perhaps adding other features such as accelerated warm-up ordecreased re-strike time.

Retrofitting Opportunities

This section describes some of the common retrofit opportunities for buildings withHID lamps.

Mercury Vapor Lamps.

1. Some mercury vapor lamps may be replaced by a similar sized metal halide (“I-line”) lamp. The most common is a 325-watt metal halide specifically designed foroperating on a 400-watt mercury vapor ballast, saving 75 watts per luminaire andgenerating 30% more light.

2. High-wattage mercury vapor luminaires are increasingly rare. Those withoutprecise optical systems, such as decorative outdoor lighting poles, most landscapelighting, and many types of industrial lighting, can be converted to a metal halidelamp of about 60% of the watts, generally using diffuse-coated lamps, with minor


3-27

concern for lamp optical centering (see below). Unless an advanced metal halidesystem is being considered, it is unlikely that the socket or wiring will requirechanging, as there are many metal halide and high-pressure sodium lamps that aresimple screw-in replacements to mercury vapor lamps.

3. Even if the luminaire has a precise optical system, in many cases a conversion tometal halide will work well. Generally replace a mercury vapor lamp with a metalhalide using 60% of the mercury lamp’s rated wattage. Be certain to take intoaccount the optical center of the bulb or arc, as the lower-wattage metal halide lampwill be smaller; a socket extender or new socket assembly may be needed. Be certainto note whether the metal halide lamp requires a “pulse rated” socket, meaning theignitor is not within the lamp (typical for 150 watts and less and certain high-performance lamps and the latest “energy-efficient” lamp-ballast systems).Generally a pulse-rated socket signifies that the ignitor must be physically near thelamp and that the wiring between ignitor and socket be rated for high voltagepulses as well.

4. Low-wattage mercury vapor lamps can be retrofitted with compact fluorescentlamps so long as the optical system is insignificant. For instance, a 70–100-wattmercury vapor lamp may be replaced with an electronically-ballasted 40–42-watt“triple” or coiled compact fluorescent and produce the same maintained lightoutput, taking advantage of the superior lumen maintenance of the modernamalgam compact fluorescent lamp and the low-temperature starting of theelectronic ballast. Or, a low-wattage metal halide (50 watts for this example) mightbe used—but note that this may also require pulse rated socket and socket wiring.The primary risk with fluorescent-for-HID conversions of any kind is temperatureextremes—very warm or very cold environmental conditions often favor HID,electronic ballasts for fluorescent notwithstanding.

5. In all cases, before retrofitting a mercury vapor luminaire, investigate completeluminaire replacement. The majority of the mercury luminaires in service are 15–20years old or more. In addition, conversion may cost less if the labor of changingluminaires is less than the labor of rewiring—it often is.

Table 3-11Mercury Vapor Input Watts

Lamp Watts Ballast Type Input Watts Notes

75 Reactor

CWA

85

99

120 volt at PF=.45

HPF

100 CWA 110

120–125

120 volt at PF=.45

HPF

175 CWA 195–210 HPF

250 CWA 290–300 HPF

400 CWA 450 HPF

1000 CWA 1050–1060 HPF


3-28

Metal Halide Lamps. Many metal halide luminaires cannot be retrofitted within theeconomic parameters of an energy efficiency project. The basic source is too efficaciousand the near point-source of the arc tube lends itself to efficient luminaires. However,there are a few ways in which savings might be achieved by retrofitting.

1. If frequent switching is being avoided due to the warm-up and re-strike problemsof the metal halide lamp, consider retrofitting with a new fluorescent lightingsystem.

2. When a space is overlighted, install a dimming ballast to reduce idling power.Applications might include warehouses, areas with some daylighting, and airportramps when aircraft are no longer being serviced.

3. Some metal halide lamps are burning-position sensitive and will not operate properlyunless the arc tube is in a particular alignment relative to gravity. Lamps with thesuffix “U”, e.g. M250/U, can be operated in any position (although slightly betteroperation may occur in some positions). Position-specific lamps include suffixeslike:

x /BU base up (usually within 15 degrees)

x /BD base down (usually within 15 degrees)

x /BUH base up to horizontal

x /BDH base down to horizontal

x /HOR horizontal (usually within 45 degrees)

There are ways to prevent many of these lamps from being used incorrectly. Forexample, the /HOR “high-output” single-ended lamps have a slightly curved arctube that must be aligned with the curve oriented vertically or the lamp will operatequite poorly. Note that the high-output lamps generate about 10% more lumensthan universal lamps of the same wattage. It is important to retrofit position-sensitive lamps properly. Also note that there may be some retrofit advantagethrough the higher light output, the difference in light between universal and highoutput lamps is not great.

4. There are a few “low-wattage” metal halide lamps allowing direct replacement.These include the 360-watt replacement for the 400-watt lamp and the 950-wattreplacement for the 1000-watt lamp. These are socket-for-socket changeoutproducts.

5. Some systems lend themselves toward new ballasts and lamps. In particular, the400-watt standard metal halide can be changed to a 360-watt lamp and reactorballast if the input power is 277 volts, resulting in negligible light level change andsavings of about 70 watts per luminaire. Other systems may be harder toimplement.

6. There is a hybrid ballast system for metal halide lamps that attempts to betterregulate arc voltage over life, thereby increasing lumen maintenance. Underfavorable conditions a 250-watt hybrid system might be used to replace a 400-wattsystem. This could result in equal maintained illumination even if the initial


3-29

illumination of the 250-watt system is much lower. Remember, lumen maintenanceof metal halide lamps is notoriously poor; but the actual cause is due to lampvoltage rise caused by slow changes in lamp chemistry and therefore, the lamp’selectric resistance. A hybrid ballast compensates for the changes, whereas amagnetic ballast cannot.

7. Most metal halide luminaires incorporate a lens to protect room occupants in case ofa lamp explosion. In some luminaire types, such as downlights and industrialfixtures, the lens may collect dirt which would not otherwise affect an open bottomluminaire. Consider changing the socket to the type suitable for metal halide lampsthat have an internal arc-tube shroud. The slight reduction in initial lamp lumens ofthe shrouded-tube lamp, about 10%, is offset by eliminating the light absorption ofthe original lens. The result might be much higher maintained light levels as theluminaire’s dirt depreciation (LDD) can improve dramatically.

8. Very low wattage metal halide, especially lamps under 100 watts, might be replacedwith a 40–42-watt compact fluorescent.

9. There are several special metal halide families of which some are quite common,like the double-ended 70- and 150-watt HQI. Make special note of these lamps, asthe opportunities are very limited. For instance, there are electronic ballasts for the70-watt HQI lamp that offer both improved lumen maintenance and higherefficiency than magnetic ballasts. But due to many of the technical properties ofthese lamps, they will otherwise be hard to change to save energy.

10. There are also many uncommon metal halide lamps, like the CSI, CID, HMI, etc.Most of these are special purpose lamps intended for film, theater, or otheruncommon applications. Their unusual nature suggests looking into otherluminaires and lamps if the situation seems appropriate for a change.

The following tables show typical metal halide lamps intended for general use as ofsummer 1996. Among the areas of evolution for new products will be low-wattagehigh CRI lamps; high-wattage 3000K, high CRI lamps; and low-wattage high CRIprojector lamps.


3-30

Table 3-12Metal Halide Lamp Data—Non-Reflector Lamps

Watts ANSICode

Input

Watts

Lamp

Type

Base Envelope CCT(K)

CRI Coated orClear

InitialLumens(nominal)

NominalLamp Life(Hrs.)

32 M100 38 E V Medium E17 3000 70 Coated 2500 10,000

39 M130 47 E U G12 T6 3000 81 Clear 3300 9000

50 M110 72 HX U

U

U/SB

Medium E/ED17 370040004000

706565

CoatedClearClear

340034003200

500050005000

BU105 G12 T8 4000 65 Clear 3400 10,000

BU105 3200 65 Clear 3400 10,000

U/Open Medium E/ED17 3200 65 Clear 3300 5000

U/Open 3200 65 Coated 2800 5000

70 M98 94 HX U

U

U/SB

BUBD15

BUBD15

U

Medium

Mogul

E/ED17

E/ED28

37004000

3200

320040004000

706565

6565

65

CoatedClearClear

CoatedClear

Clear

56005600

6000

600052005600

10,00010,00010,00010,000

BU105

U

U

G12 T8 4000

3000

3000

65

83

83

Clear

Clear

Coated

5600

6200

6000

10,000

BU105 3200 65 Clear 5600 10,000

U/Open Medium E/ED17 3200 65 Clear 5200 10,000

U/Open 3200 65 Coated 4800 10,000

U/Open 3000 83 Clear 5900 10,000

U/Open 3000 83 Coated 5700 10,000

Vert Open 3200 65 Clear 6000 10,000

Vert Open 3200 65 Coated 5600 10,000

Vert Open Mogul E/ED17 3200 65 Clear 6000 10,000


3-31

Table 3-12Metal Halide Lamp Data—Non-Reflector Lamps (continued)

Watts ANSICode

Input

Watts

Lamp

Type


CRI Coated or Clear InitialLumens(nominal)


70 M85 94 HX HOR45 RSC T6.5 4200 65 Clear 5500 7500

80 E HOR45 3500 65 Clear 5500 7500

HOR45 3000 65 Clear 5000 7500

HOR45 4200 85 Clear 5500 10,000

HOR45 3000 81 Clear 5000 10,000

HOR45 T6 3000 82 Clear 6200 6000

BU105 G12 T8 4000 65 Clear 3400 10,000

BU105

U

3200

3000

65

83

Clear

Clear

3400

6200

10,000

6000

75 M101 94 HX BU15 Medium ED17 3200 65 Clear 5600 5000

BU15 3200 70 Coated 5200 5000

100 M90 125 HX U

U

U/SB

U

U

Medium

Mogul

E/ED17

E/ED28

37004000400052004000

7065656565

CoatedClearClearClearClear

78007800760070007800

10,00010,00010,000 750010,000

BUBD15 Medium ED17 3200 65 Clear 9000 10,000

BUBD15 3200 70 Coated 8500 10,000

BU105 G12 T8 4000 65 Clear 9000 10,000

BU105 3200 65 Clear 9000 10,000

U 3000 85 Clear 9300 10,000

U 3000 85 Coated 9000 10,000

U/Open Medium E/ED17 3200 65 Clear 8500 10,000

U/Open 3200 65 Coated 8000 10,000

U/Open 3000 85 Clear 8800 10,000

U/Open 3000 85 Coated 8500 10,000

Vert/Open 3200 65 Clear 9000 10,000

Vert/Open 3200 65 Coated 8500 10,000

Vert/Open Mogul E/ED17 3200 65 Clear 9000 10,000

100 M91 130 HX HOR45 RSC T7.5 4200 65 Clear 6800 7500

150 M107 195 CWA U

U

U

Medium

Mogul

E/ED17

E/ED28

370040004000

706565

CoatedClearClear

135001350013500

10,00010,00010,000

U 3700 70 Coated 13500 10,000

BUBD15 Medium ED17 3200 70 Coated 12500 10,000

150 M102 180 HX U Medium ED17 4000 65 Clear 15000 15,000

U 3700 70 Coated 14250 15,000

Vert open E17N 4000 65 Clear 14250 15,000

Vert open 3700 70 Coated 13500 15,000

Vert open 3200 70 Clear 14250 15,000

Vert open 3200 75 Coated 13500 15,000

U Mogul ED28 4000 65 Clear 15000 15,000

U 3700 70 Coated 14250 15,000

Vert open OP Mog ED28 3200 65 Clear 14250 15,000

Vert open 3200 70 Coated 13500 15,000

Vert open 2700 75 Coated 13500 15,000


3-32


Watts ANSICode

Input

Watts

Lamp

Type




150 M81 180 HX HOR45 RSC T7.5 4200 65 Clear 12,000 10,000

HOR45 3500 65 Clear 12,000 10,000

HOR45 3000 65 Clear 11,500 10,000

HOR45 4200 85 Clear 11,250 10,000

HOR45 3000 81 Clear 11,000 10,000

HOR45 T6 3000 85 Clear 13,500 6000

U G12 T6 3000 85 Clear 13,500 6000

175 M57 205CWA

U

U

U

U

U/SB

U

Medium

Mogul

E/ED17

E/ED28

370040003700400040005200

706570656565

CoatedClearCoatedClearClearClear

15,00015,00014,00014,00013,60012,000

10,00010,00010,00010,00010,000 7500

BU15 Medium ED17 3200 70 Coated 14,000 10,000

BUBD15 Mogul ED23½ 3200 65 Clear 16,600 10,000

BUBD15 3200 65 Coated 15,750 10,000

BU15 E/ED28 3200 65 Clear 14,000 10,000

BU15 4000 65 Clear 14,000 10,000

BU15 3200 70 Coated 13,000 10,000

BU15 3700 70 Coated 14,000 10,000

HOR45 PO Mogul E/ED28 3200 70 Coated 14,000 10,000

HOR45 3700 70 Coated 15,000 10,000

HOR45 4000 65 Clear 15,000 10,000

HOR45 4200 70 Coated 15,000 10,000

HOR45 4700 65 Clear 15,000 10,000

200 U Mogul ED28 4000 65 Clear 21,000 15,000

U PO Mogul ED28 3700 70 Coated 20,000 15,000

Open Vert OFMogul ED28 4000 65 Clear 19,000 15,000

Open Vert OF Mogul ED28 4000 65 Clear 20,000 15,000

Open Vert OF Mogul ED28 3700 70 Coated 20,000 15,000

Open Vert OF Mogul ED28 3200 70 Coated 19,000 15,000

225 M58 265CWA

BU15 Mogul ED28 4000 65 Clear 19,000 10,000

(EnergySavingLamp)

BU15 3700 70 Coated 19,000 10,000

OpenBU15 4000 65 Clear 19,000 10,000

OpenBU15 3700 70 Coated 19,000 10,000


3-33


Watts ANSICode

InputWatts

LampType




250 M58 290CWA

U Mogul E/ED28 3700 70 Coated 20,500 10,000

U 4000 65 Clear 20,500U/SB 4000 65 Clear 20,000U 5200 65 Clear 19,000 7500U ED18 4000 65 Clear 20,500 10,000BU15 Mogul E/ED28 3200 70 Coated 20,500 10,000BU15 3700 70 Coated 23,000 10,000BU15 4000 65 Clear 23,000 10,000HOR45 PO Mogul E/ED28 3200 70 Clear 20,500 10,000HOR45 3700 70 Coated 23,000 10,000HOR45 4000 65 Clear 23,000 10,000

M80 HOR15 RSC T9.5 4200 65 Clear 20,000 10,000HOR45 4200 85 Clear 20,000 10,000HOR45 RSC/Fc2 T9.5 5400 93 Clear 19,000 10,000HOR45 4200 85 Clear 20,000 10,000HOR15 4200 65 Clear 20,000 10,000HOR45 3200 85 Clear 20,000 10,000

325 H33 375CWA

U Mogul ED37 4000 65 Clear 28,000 20,000

Mercuryretrofit

U 3700 70 Coated 28,000 20,000

350 M131 408CWA

U Mogul ED37 4000 65 Clear 36,000 20,000

375 LR U 3700 70 Coated 34,500 20,000HOR45 PO Mogul 4000 65 Clear 35,000 20,000HOR45 3700 70 Coated 33,500 20,000U Mogul ED28 4000 65 Clear 36,000 20,000U 3700 70 Coated 34,500 20,000HOR45 PO Mogul 4000 65 Clear 35,000 20,000HOR45 3700 70 Coated 33,500 20,000Open Vert OFMogul BT37 4000 65 Clear 36,000 20,000Open Vert 3700 70 Coated 34,500 20,000Open Vert ED28 4000 65 Clear 36,000 20,000Open Vert 4000 65 Clear 34,500 20,000

360 M59 418CWA

BU15 Mogul ED37 4000 65 Clear 35,000 20,000

(EnergySavingLamp)

BU15 3700 70 Coated 35,000 20,000

BD15 4000 65 Clear 35,000 20,000HOR45 PO Mogul 4000 65 Clear 35,000 20,000HOR45 3700 70 Coated 35,000 20,000BU15 Mogul ED28 4000 65 Clear 35,000 20,000Open-BU15 BT37 4000 65 Clear 35,000 20,000Open-BU15 3700 70 Coated 35,000 20,000


3-34


Watts ANSICode

InputWatts

LampType




400 M59 458CWA425 LR440CWI (2Lamp,eachlamp)

UUU/SBUUU

Mogul E/ED37

ED28

370040004000520037004000

706565657065

CoatedClearClearClearCoatedClear

36,00036,00035,00032,50036,00036,000

20,00020,00020,00015,00020,00020,000

BU15 Mogul E/ED37 3200 70 Coated 36,000 20,000BU15 3700 70 Coated 40,000 20,000BU15 4000 65 Clear 40,000 20,000BD15 4000 65 Clear 40,000 20,000HOR45 PO Mogul E/ED37 3200 70 Coated 36,000 20,000HOR45 3700 70 Coated 40,000 20,000HOR45 4000 65 Clear 40,000 20,000HOR20 4000 65 Clear 40,000 20,000HOR20 4000 65 Clear 40,000 20,000Open/BU15Mogul E/BT37 3200 70 Coated 35,000 20,000Open/BU15 3500 70 Coated 35,500 20,000Open/BU15 3700 65 Clear 35,500 20,000

400 M108 460CWA

HOR45 RSC T10 4200 65 Clear 34,000 15,000

HOR45 Fc2D T10 4200 65 Clear 40,000 15,000HOR45 Fc2 T10 5400 93 Clear 33,000 10,000

950 M47 1040CWA

U Mogul BT56 4000 65 Clear 105,000 12,000

1000 M47 1090CWA

UUU/SBU

Mogul BT56 3700400040005200

70656565

CoatedClearClearClear

110,000110,000107,00080,000

12,00012,00012,000 9000

BU15 3400 70 Coated 117,000 12,000BU15 3900 65 Clear 117,000 12,000BU15 3900 65 Clear 117,000 12,000HOR60 3400 65 Clear 117,000 12,000OpenBU15 3400 65 Coated 110,000 12,000OpenBU15 3400 65 Clear 110,000 12,000

1000 M47SpecialIgniter

1090CWA

HOR15 RSC T9.5 3800 65 Clear 100,000 3000

1500 M48 1595CWA

UU

Mogul BT56 34004000

6565

ClearClear

155,000155,000

3000 3000

HBU105 Mogul BT56 3400 65 Clear 155,000 3000HBD105 3400 65 Clear 155,000 3000HOR60 PO Mogul 3400 65 Clear 162,000 3000


1595CWA

HOR15 RSC T7.5 3800 65 Clear 150,000 2000

HOR15 T9.5 3800 65 Clear 150,000 2000

1650 M48 1750CWA

HOR60 PO Mogul BT56 3400 65 Clear 177,000 3000

1800 Special 1975 HOR15 Special T-D 5600 92 Clear 150,000 4500


3-35


Watts ANSICode

InputWatts

LampType




400 M59 458CWA425 LR440CWI (2Lamp,eachlamp)

UUU/SBUUU

Mogul E/ED37

ED28

370040004000520037004000

706565657065

CoatedClearClearClearCoatedClear

36,00036,00035,00032,50036,00036,000

20,00020,00020,00015,00020,00020,000

BU15 Mogul E/ED37 3200 70 Coated 36,000 20,000BU15 3700 70 Coated 40,000 20,000BU15 4000 65 Clear 40,000 20,000BD15 4000 65 Clear 40,000 20,000HOR45 PO Mogul E/ED37 3200 70 Coated 36,000 20,000HOR45 3700 70 Coated 40,000 20,000HOR45 4000 65 Clear 40,000 20,000HOR20 4000 65 Clear 40,000 20,000HOR20 4000 65 Clear 40,000 20,000Open/BU15Mogul E/BT37 3200 70 Coated 35,000 20,000Open/BU15 3500 70 Coated 35,500 20,000Open/BU15 3700 65 Clear 35,500 20,000

400 M108 460CWA

HOR45 RSC T10 4200 65 Clear 34,000 15,000

HOR45 Fc2D T10 4200 65 Clear 40,000 15,000HOR45 Fc2 T10 5400 93 Clear 33,000 10,000

950 M47 1040CWA

U Mogul BT56 4000 65 Clear 105,000 12,000

1000 M47 1090CWA

UUU/SBU

Mogul BT56 3700400040005200

70656565

CoatedClearClearClear

110,000110,000107,00080,000

12,00012,00012,000 9000

BU15 3400 70 Coated 117,000 12,000BU15 3900 65 Clear 117,000 12,000BU15 3900 65 Clear 117,000 12,000HOR60 3400 65 Clear 117,000 12,000OpenBU15 3400 65 Coated 110,000 12,000OpenBU15 3400 65 Clear 110,000 12,000


1090CWA

HOR15 RSC T9.5 3800 65 Clear 100,000 3000

1500 M48 1595CWA

UU

Mogul BT56 34004000

6565

ClearClear

155,000155,000

3000 3000

HBU105 Mogul BT56 3400 65 Clear 155,000 3000HBD105 3400 65 Clear 155,000 3000HOR60 PO Mogul 3400 65 Clear 162,000 3000


1595CWA

HOR15 RSC T7.5 3800 65 Clear 150,000 2000

HOR15 T9.5 3800 65 Clear 150,000 2000

1650 M48 1750CWA

HOR60 PO Mogul BT56 3400 65 Clear 177,000 3000

1800 Special 1975 HOR15 Special T-D 5600 92 Clear 150,000 4500


3-36

Table 3-13 - Lamp Data—Metal Halide With Internal Reflectors

Watts ANSICode

Base Bulb Shape CCT(K)

CRI BeamType

BeamSpreadDegrees

Center BeamCP (nominal)


Notes

39 M130 Medium PAR20PAR20PAR30LPAR30L

3000 81 SpotFloodSpotFlood

10301030

28,000600042,0006500

9000 Openfixture

70 M98 Medium R40 4000 65 Spot 15 60,000 10,000Flood 70 1500 10,000

Med. Skt. PAR38 4300 65 Spot 15 40,000 5000 Openfixture

Flood 35 12,000 5000 Openfixture

3200 65 Spot 20 18,000 7500 Openfixture


Flood 65 3000 7500 Openfixture



Wide flood 65 4000 7500 Openfixture

Medium PAR30L 3000 83 Spot 10 48,000 6000 Openfixture


Mog. Prong PAR56 4300 65 Spot 20 105,000 5000


Med. Skt. PAR38 3200 65 Spot 20 26,000 7500 Openfixture





Wide flood 65 6000 7500 Openfixture




250 M58 Mog. Prong PAR64 4300 65 Spot 15 210,000 5000

400 M59 Mog. Prong PAR64 4300 65 Spot 30 120,000 5000


3-37

1000 * Mog. Prong PAR64 4000 88 Spot 8 1,500,000 5000 *CSIType

5600 92 Spot 8 1,200,000 5000 *CIDType

Table 3-14 - Basic Application Notes for Metal Halide and HPS Lamp Tables

Item ConsiderationsWatts Nominal lamp watts at 100 hours. Actual lamp watts will vary over life and depending on input voltage and

other factors.ANSI Code American National Standards Institute (ANSI) code defining lamp physical and electrical characteristics to

ensure interchangability and standardization among manufacturers. Metal halide codes begin in M, HPS codesin S, mercury vapor lamp codes in H.

Input Watts Nom. Ballast input watts. Note that the difference between input watts and lamp watts is wasted energydissipated as ballast heat.Ballast type varies input watts. Ballast types as follows:E Electronic or hybrid electronicHX High reactance autotransformerCWA Constant wattage autotransformerCWI Constant wattage isolated transformerLR Linear reactor

Lamp Type Describes lamp operating position and fixture requirements as follows:U = universal operating, enclosedU/SB = universal operating, enclosed, silver bowlU/Open = universal operating, open fixtureVert open = vertical burning +/- 15q base up or down, open fixtureBUBD15 = base up or base down +/- 15°, enclosedBU15 = base up +/- 15°, enclosed fixtureBD15 = base down +/- 15°, enclosed fixtureHBU105 = horizontal to base up +/- 105°, enclosedHOR15 = horizontal +/- 15°, enclosedHOR45 = horizontal +/- 45°, enclosedHOR20 = horizontal +/- 20°, enclosedHOR60 = horizontal +/- 60°, enclosedNote that most double-ended and G12 based metal halide lamps require enclosures which prevents UVradiation from the luminaire.

Base Describes lamp base or socket as follows:Medium = Pulse-rated medium baseMogul = Mogul base, usually pulse-ratedPO Mogul = position-oriented mogul baseG12 = bi-pin pulse-rated G12 baseOF Mogul = open-flanged mogul base, usually pulse-rated, designed to accept only open fixture-rated lampsRSC = recessed single contact (double-ended lamp), pulse-ratedFC2. FC2D = single contact, tab specific (double-ended lamp), pulse-ratedMogul Prong = mogul end prongSpecial “hot re-strike” versions of some lamps require special sockets and separate anode wires to allow highvoltage pulse (20–30kV) to reignite a hot lamp.

Envelope Lamp bulb type and shape. Letters designate shape as follows:E = ellipticalED = modified ellipticalB = bulb (generic and arbitrary)T = tubularBT = bulb/tubularR = reflectorPAR = parabolic aluminized reflectorNumbers indicate lamp diameter in 1/8” increments.Lamp sizes (overall length, etc.) are standardized by NEMA and ANSI.

CCT Correlated color temperature in Kelvins. Note that metal halide lamps may not visually match fluorescent orincandescent lamps of the same CCT.

CRI Color rendering index.Coated or Clear Clear metal halide lamps generally have lower CRI than coated metal halide lamps but permit more effective

focusing of light due to small source area of arc tube. Coated lamps diffuse light over the surface of the lamp


3-38

and are better suited for conditions where the lamp might be viewed (as in downlighting or floodlighting) orwhere a more uniform source is needed.

Lamp lumens Rated lamp lumens at 100 hours in preferred operating position. Note that lamp lumen depreciation can be amajor factor in metal halide lamps, and that mean lumens can be as low as 75% of initial.

Nominal Life Rated lamp life in preferred operating position. Note that operating position and other factors can affect lamplife.

High-Pressure Sodium Luminaires. Like metal halide luminaires, high-pressuresodium luminaires are difficult to make more energy-efficient. HPS lamps areextremely long-lived, energy-efficient, and cost-effective. Moreover, there are few, ifany, low-wattage lamps that can be used for direct replacements at reasonable cost. Theopportunities are generally limited to the following:

1. As with metal halide (above), replace HPS systems with fluorescent lightingsystems in spaces where switching opportunities are being avoided due to thewarm-up and re-strike time of HPS.

2. Also, as with metal halide, add hi-lo or dimming ballast systems where idlingperiods of reduced lighting are appropriate.

3. Similarly, very low wattage high-pressure sodium might be replaced with high-wattage compact fluorescent lamps in similar luminaires. But unlike metal halidelamps, HPS lamps do not suffer the severe lumen depreciation; so for the most part,an electronically-ballasted compact fluorescent of32–40 watts might be a suitable replacement for an HPS lamp of 50–70 watts at themost.

“Deluxe” sodium lamps are very much like regular HPS lamps in many considerationsexcept that dimming features are generally not applicable. “White” sodium lamps arefairly low efficacy, medium-life lamps, and are not at all like regular HPS sources.Low-wattage white sodium luminaires can be evaluated for retrofit depending on theapplication. For instance, if being used as a wallwasher or down light, it may bepossible to retrofit the luminaire with a compact fluorescent lamp of lower wattage.Higher-wattage white sodium lamps might be retrofitted with a lower-wattage metalhalide. Because of the color rendition and other issues related to these applications, beespecially aware of the design intent and how the outcome might maintain or improvethe situation.

The popularity of HPS lamps for exterior lighting is now being challenged. Researchindicates significant potential for improved apparent brightness and visibility with“white” light sources like metal halide and fluorescent in many lighting situationsindoors and out. Some retrofit situations are intended solely to improve color renderingand gain the increased “visibility.” When doing so, consider replacing standard HPSsystems with advanced metal halide or fluorescent systems so that some energy savingsmight be realized anyway.

For the most part, innovations and developments in HPS lamps/ballast technologyappear to be reaching maturity. However, there is one significant development. Newlamps are available that do not cycle on-and-off at the end of their life like typical HPS


3-39

lamps, removing one of the maintenance hassles. The following tables represent themarketplace of general illumination lamps as of summer 1996.


3-40

Table 3-15Lamp Data—High-Pressure Sodium, Non-ReflectorWatts ANSI

CodeInputWatts

Base Bulb Sha pe Coated orClear

CCT CRI InitialLumens(nominal )

NominalLamp Life(Hrs. )

35 S76 55 HX Medium E/B17 Clear 2000 18 2250 16,000Coated 2000 18 2150 16,000

T10 Clear 2000 18 2100 16,000S99 45 Elec PG12 T10 Clear 2700 85 1250 10,000

50 S68 65 HX Medium E/B17 Coated 2050 20 3800 16,000Clear 2050 20 4000 16,000

T10 Clear 2050 20 3700 16,000ED17 Clear 2700 85 2350 10,000

Mogul ED23½ Clear 2050 20 4000 16,000Coated 2050 20 3800 16,000

S104 68 Elec PG12 T10 Clear 2700 85 2500 10,00070 S62 90 HX Medium E/B17 Coated 2050 20 5985 16,000

Clear 2050 20 6300 16,000T10 Clear 2050 20 6300 16,000

Mogul E/ED23½ Coated 2050 20 5985 16,000Clear 2050 20 6300 16,000Clear 2050 20 6300 16,000

Medium B17 Clear 2200 65 3800 15,000Coated 2200 65 3600 15,000

ED17 Clear 2200 65 4400 15,000Coated 2200 65 4180 15,000


S88 94 HX RSC T6 Clear 2200 22 7000 10,00095 Proprietary 122 Elec Med T10 Clear 2800 79 5200 10,000

E27 Clear 2800 79 5000 10,000PG12 Clear 2800 79 5200 10,000

100 S54 125 HX Medium B17 Coated 2050 20 8500 40,000Clear 2050 20 9500 24,000

Mogul E/ED23½ Clear 2050 20 9500 24,000Coated 2050 20 8800 24,000Clear 2050 20 9100 40,000

Medium ED17 Clear 2200 65 7300 15,000Coated 2200 65 6940 15,000


S105 120 Elec Medium ED-17 Clear 2700 85 4900 10,000PG12 T10 Clear 2700 85 5200 10,000

150 S55 185 HX Medium B17 Coated 2100 22 15,000 24,000Clear 2100 22 16,000 24,000

Mogul E/ED23½ Clear 2100 22 16,000 24,000Coated 2100 22 15,000 24,000Clear 2100 22 15,600 40,000

S56 185 CWA Mogul E28 Clear 2100 22 15,000 24,000150 S55 185 HX Medium B17 Clear 2200 65 10,500 15,000

Coated 2200 65 9900 15,000ED17 Clear 2200 65 12,000 15,000

Coated 2200 65 11,000 15,000Mogul E23½ Clear 2200 65 10,500 15,000

Coated 2200 65 9900 15,000ED23½ Clear 2200 65 12,000 15,000

Coated 2200 65 11,000 15,000M81 180 HX RSC T7.5 Clear 2200 22 15,000 10,000H39 180 CWA Mogul BT28 Clear 2200 22 13,000 24,000


3-41

Table 3-15Lamp Data—High-Pressure Sodium, Non-Reflector (continued)

Watts ANSICode

InputWatts

Base Bulb Shape Coated orClear

CCT CRI InitialLumens(nominal)


200 S66 245 CWI Mogul E/ED18 Clear 2100 22 22,000 24,000Clear 2100 22 22,000 40,000

215 H37 295 CWA Mogul BT28 Clear 2200 22 20,000 16,000250 S50 295 CWA Mogul E28 Coated 2100 22 26,000 24,000

E/ED18 Clear 2100 22 27,500 24,000Clear 2100 22 30,000 24,000Clear 2100 22 27,500 40,000

T14.5 Clear 2100 22 29,000 24,000Clear 2100 22 28,500 40,000

Mogul E/ED18 Clear 2200 65 23,000 15,000E28 Coated 2200 65 20,000 15,000

RSC T7 Clear 2200 22 27,000 24,000310 S67 355 CWA Mogul E/ED18 Clear 2100 22 37,000 24,000360 H33 425 CWA Mogul BT37 Clear 2200 22 38,000 12,000400 S51 450 CWA Mogul E/ED37 Coated 2100 22 47,500 24,000

E/ED18 Clear 2100 22 50,000 24,000Clear 2100 22 50,000 40,000

T14.5 Clear 2100 22 50,000 24,000Clear 2100 22 50,000 40,000

Mogul ED18 Clear 2200 65 37,500 15,000E28 Clear 2200 65 37,400 10,000

Coated 2200 65 35,500 10,000RSC T7 Clear 2200 22 50,000 24,000

600 S106 655 CWA Mogul T16 Clear 2100 22 90,000 24,000750 S111 820 CWA Mogul BT37 Clear 2100 22 110,000 24,000880 H36 965 CWA Mogul E25 Clear 2200 22 102,000 12,0001000 S52 1080 CWA Mogul E-25 Clear 2100 22 140,000 24,000

Clear 2100 22 140,000 40,000T21 Clear 2100 22 140,000 24,000

Low-Pressure Sodium Luminaires. Due to the visibility and color distinction issuessurrounding LPS lighting, there is a strong trend away from the source to whiter lightsources. Even cities that once touted their energy-efficient LPS systems are quietlychanging to HPS or metal halide for major street and roadway systems.

Because of the unique optical package of LPS lamps, there are no retrofits for thistechnology other than the replacement of the luminaire. In fact, changing from LPS toanother light source may in fact use more energy.

Interchangeable HID Lamps. Occasionally, there may be a situation where a screw-inreplacement for an existing HID lamp is an effective and economical choice. Some ofthese situations include:

xx Metal halide lamps that replace HPS. The color deficiencies of HPS occasionally needto be overcome. There are a few metal halide products for this application.

xx Metal halide lamps that replace mercury. While mercury and metal halide lamps arevery similar, there are a few specific metal halide lamps which perform optimally


3-42

on existing mercury ballasts; the 325-watt lamp, in particular, replaces the 400-wattmercury vapor lamp: it improves color rendering, increases light levels, and savesenergy at the same time.

xx HPS lamps that replace mercury. These lamps were designed for and extensively usedin street lighting systems and for industrial luminaires.

Luminaire Retrofit Technologies

This section describes technologies that can be used to improve the efficiency ofluminaires. A luminaire or light fixture is a complete system that includes a housing,lamp, ballast, and lens or diffuser. Lamps and ballast technologies are treated in theprevious section. This section focuses on technologies that can be used to improve theefficiency of the luminaire. The efficiency of a luminaire is the ratio of light that leavesthe luminaire compared to the light produced by the source (lamps and ballasts). Thetechnologies presented in this section include reflectors that are installed inside troffersor as a part of fluorescent strip lights, lenses for diffusing and directing light that leavesluminaires, and special retrofit kits available to convert incandescent fixtures tocompact fluorescent.

Table 3-16Lamp Data—High-Pressure Sodium, Reflector Lamps

Watts ANSICode

Base Bulb Shape CCT(K)

CRI Beam Type BeamSpread

Center Beam CP(nominal)


Notes

35 S76 Medium R-38 2100 18 WFL 65 DEG 1000 16,000

70/75 S62 Med. Skt. PAR-38 2100 21 WFL 65 DEG 2200 10,000

PAR-38 2100 21 FL 50 DEG 4400 16,000

Med. Prong PAR-38 2100 21 WFL 65 DEG 2200 10,000

Medium R-38 2100 65 WFL 65 DEG 1800 10,000 "Deluxe"

Table 3-17Low-Pressure Sodium Input Watts

Lamp Watts Lamp and Ballast Type Input Watts Note

18 L-69-HX 31

35 L-70-HX 60 480V Ballast is a reactor type

55 L-71-HX 80 480 V Ballast is a reactor type


135 L-73-HX 178 480 V Ballast is a reactor type



3-43

Table 3-18Lamp Data—Interchangeable HID Lamps

Watts Replaces ANSIBallast

BulbShape

CCTK

CRI CoatedorClear

BurnPos.

InitialLumens

Lamp Life(Hrs.)

Notes

Metal Halide Lamps

250 250W HPS S50 E/ED28 3700 70 Coated BU15 20,500 5000 Must be enclosed

4000 65 Clear BU15 20,500 5000 Must be enclosed

400 400W HPS S51 E/ED28 4000 65 Clear UNIV 36,000 5000

E/ED37 3700 70 Coated BU15 40,000 10,000

4000 65 Clear BU15 40,000 10,000

T14.5 5200 90 Clear UNIV 33,000 9000 Must be enclosed

325 400W MV H33* E/ED37 4000 65 Clear UNIV 28,000 20,000

3700 70 Coated UNIV 28,000 20,000

400 400W MV H33* E/ED37 4000 65 Clear UNIV 36,000 15,000 Works on M59Ballast

3700 70 Coated UNIV 36,000 15,000 Works on M59Ballast

950 1000W MV H15/H36 BT56 4000 65 Clear BU15 100,000 12,000 Works on M47Ballast

4000 65 Clear BD15 100,000 12,000 Works on M47Ballast

High-Pressure Sodium Lamps

150 175W MV H39 BT28 2100 22 Clear UNIV 13,000 24,000



880 1000W MV H15/36 E25 2100 22 Clear UNIV 102,000 12,000

Notes:

*Not all mercury ballasts are suitable for interchangeable lamps.Metal halide lamp values are for vertical burning position.Open fixtures for all HPS and vertical metal halide lamps; other metal halide positions require suitable enclosed luminaire.Lumen and lamp life ratings are nominal and are based on specific manufacturer data. Check with individual manufacturers forexact data.System input watts will vary depending on the ballast used. Contact the ballast manufacturer for actual input wattage.

Optical Reflectors

Many interior environments are overlighted because older buildings were designed tostandards now considered obsolete or because tasks have changed. For example, manyVDT-type tasks today were at one time performed with paper and pencil—a taskrequiring significantly higher levels of illuminance. Obviously, if a space has twice theilluminance required to perform a given task, one may simply remove half of the lampsand ballasts from luminaires in the space. However, many spaces can only tolerate a


3-44

reduction in maintained illuminance of about 30%. These spaces are potentialcandidates for the use of optical reflectors.

An optical reflector is typically a thin aluminum sheet having a mirror-like (specular)finish on one side. A specular reflector is designed to replace a luminaire's existingwhite (diffuse) reflector. This usually results in raising the efficiency of the luminairesomewhat by directing more of the lamps' lumen output toward the task area. Incertain circumstances, a space that is overlighted by, for example, a four-lampluminaire, will receive adequate illuminance from the same luminaires modified to usetwo lamps and an optical reflector.

Figure 3-9 Optical Reflectors

Specular and Diffuse Reflection and Luminaire Efficiency

Not all of the light exiting a luminaire is useful light. Some of the light may beabsorbed by room surfaces, and other portions may contribute to glare.

The typical fluorescent luminaire uses a white diffuse surface to reflect light out of thefixture to where it can be used. This can result in a portion of the light emitted from thelamps undergoing many reflections before leaving the luminaire. Even if the diffusesurface is a highly reflective 85%, after five reflections the fraction of light remainingwill be

(0.85)u(0.85)u(0.85)u(0.85)u(0.85) = 0.44

It follows that if the number of reflections could be minimized, luminaire efficiencywould be improved, and more useful light could be obtained from fewer lamps.

The reflectance intensity of light depends on its reflective surface. A luminaire's white,diffuse reflector reflects light into an entire hemisphere. A specular reflector, on theother hand, reflects light into a narrow angle and is therefore easier to control. Aluminaire with specular reflecting surfaces can make light exit after only a fewreflections, thereby increasing luminaire efficiency.


3-45

Although specular reflectors have been used for many years as original equipment onsome HID luminaires and on a few fluorescent luminaires, the retrofit installation ofthese reflectors (combined with delamping) on fluorescent luminaires has grownrapidly since the energy crisis of the mid-70s. Facility managers have been subjected toa barrage of claims and counter-claims concerning both the virtues and the horrors ofthe various materials and designs that are used in the industry. In spite of sometimesexcessive claims, specular reflectors have been demonstrated to improve luminaireefficiency.

Terminology

A perfect mirror is a purely specular reflector—it reflects an incoming ray out at anangle of reflection that equals the angle of incidence. Some spread will be found in thereflection from actual specular surfaces.

A perfectly diffuse reflector reflects an incoming light ray into all directions in thehemisphere above the reflecting surface. Such a reflector is called a Lambertian surface,and the reflected light obeys the cosine law.

Real materials have a combination of both specular and diffuse reflectance.

The photometric efficiency of a luminaire is a measure of how much of the light that isemitted by the lamps is able to escape absorption in the fixture:

Luminaire Photometric

Efficiency =

Total Lumens Exiting Fixture

Total Lamp Lumens

Figure 3-10 Specular and Diffuse Surfaces

Materials and Performance

There are three main material systems used to fabricate optical reflectors:


3-46

x anodized aluminum, in which an electro chemical process is applied to provide athicker oxide coating than would occur naturally.

x anodized aluminum with an applied dielectric coating that enhances reflection

x aluminum laminated to plastic film that is coated with a silver reflective surface

Installation

Reflectors are usually attached with screws, wing nuts, or specially fabricated metalparts that are attached to the lamp socket bracket. In general, the reflector designer willbend and position the reflector above the lamp to direct light out of the luminaire afteras few reflections as possible. Another design goal is to maintain uniform illuminationon the diffuser, so as to give the appearance of a full complement of lamps. The benefitof a highly reflective surface can be compromised by poor design or installation.

Prototype Testing

On large projects, you should consider making prototype installations before initiatingthe entire project. The prototype should consist of at least four luminaires in largespaces. Illuminance measurements should be made at representative locations wherethe task occurs. A suitable light loss factor (LLF) must be used to estimate themaintained illuminance. To determine what illuminance level must be maintained bythe luminaires, measure with and without daylight and task lighting where applicable.Refer to Appendix E on field measurement procedures, particularly for averagemeasurements in an area. Be sure to clean and relamp the original luminaire and agethe lamps (at least 100 hours) before making the comparison. Lamp performance is verysensitive to ambient temperature; room conditions should remain constant and theluminaire should warm up for the same amount of time for both tests (at least one hourand preferably eight hours).

Performance Data

Reflector manufacturers make various claims for the reflectance and durability of theirproducts, and offer differing warranties. Instruments that can accurately measurespecular reflectance are expensive; so one must rely on testing laboratory data forevaluations of surface reflectances. As with many types of lighting products, it isdifficult to ensure that the installed product maintains the originally specified value ofreflectance. Also, the design of the reflector affects the efficiency of the retrofitluminaire.

When dealing with contradictory, unintuitive, or surprising claims, the prudent facilitymanager should request verification of manufacturers' claims by an independent


3-47

testing laboratory, and make sure the test compares products under identicalconditions. (see Example 3-).

Rules of Thumb

The results of several studies, in which all variables except for the reflector were heldconstant, lead to two important rules of thumb:

A four-lamp luminaire modified to utilize two lamps and an optical reflector yields three lamps’worth of light. Assuming that light output from the original luminaire was measuredafter being cleaned, and fitted with the identical lamps as used in the retrofit luminaire,the modified light level would be in the range of 60–75% of the original level. Thedielectrically coated aluminum and the silver laminates perform at the high end of therange, while anodized aluminum is at the lower end. Part of this increase in efficiencyis due to the removal of obstructions (some of the lamps); part is due to the cooleroperating temperature of the delamped fixture, which is probably closer to the optimaloperating temperature for the lamps, especially for lensed luminaires that tend tooperate above optimum temperatures. As shown in Example 3-, using lamps withhigher output can compensate so that a two-lamp luminaire can actually produce thesame amount of light.

Delamping decreases lighting uniformity by around 15–20% for luminaires with a standardpattern 12 prismatic lens. The illuminance below the luminaire can be nearly as high asin the original fully lamped state due to the imaging power of the reflector, whichpredominates near the vertical. This change in uniformity may be of no consequence ina particular installation, depending on the average illuminance and the nature andlocation of the ongoing tasks in the space. The reduction in uniformity may in fact bebeneficial in an office environment with VDTs. By decreasing the proportion of lightemitted away from the vertical, a reflectorized luminaire should provide less glare thanits fully lamped counterpart.


3-48

Example 3-1Testing an Optical Reflector Manufacturer's Claim

A company claims in its product literature that "you can remove half the lamps while maintaining thesame light level." The following discussion and procedure demonstrates how you may verify (or refute)this claim.

The first step is to obtain photometric data. In this case, tests by an independent photometriclaboratory showed that the original "seasoned" (but presumably clean) luminaire has a coefficient ofutilization (CU) of 0.39. Tests also show that the same luminaire with an optical reflector has a CU of0.57 (both CUs are chosen for the same variables: RCR=5, and reflectances of 0.70, 0.50, and 0.20 for theceilings, walls, and floors, respectively).

Next you are ready to use the lumen method (see Appendix D) to calculate the delivered illuminance,as shown in the following table. These calculations are based on one luminaire for each 64 ft2 of floorarea.

Reflector

Lamp/BallastSystem

Base case Same lamp andballasts

T-8 with normalelect. ballast

T-8 with high-outputelect. ballast

Lamp F40/CW/ES F40/CW/ES F32T8/8xx F32T8/8xx

Lumens/lamp 2650 2650 2950 2950

Lamps/luminaire 4 2 2 2

Ballast Factor 0.87 0.87 0.88 1.28

Coefficient of Utilization 0.39 0.56 0.56 0.56

LLD 0.85 0.85 0.92 0.92

LDD 0.92 0.92 0.92 0.92

Maintained LampLumens

2812 2019 2460 3580

Maintained Illuminance(fc)

44 32 38 56

% Increase (Reduction) (27%) (14%) 27%

As demonstrated above, the validity of the claim depends on the assumptions that were made aboutthe lamps and ballasts that are also part of the retrofit. If the same lamps are kept, then there would bea 27% reduction in maintained illuminance. However, if the lamps and ballasts are also changed(typical), then this can make up for the reduction, especially if high-output electronic ballasts are usedthat “over drive” lamps.


3-49

Safety

To ensure that the UL rating of the original luminaire is not compromised by themodifications undertaken to install the reflector, make sure that the reflector vendorhas a UL listing for the reflector kit. UL listing involves UL inspection of themanufacturing site of the reflector kits, but not of typical installations on clients'premises.

An integral part of the prototype installation should include a careful examination ofthe reflector kit design from the perspective of safety and future maintenance. Thefollowing checklist should ensure a high quality installation.

x wiring properly concealed

x wiring protected near metal edges

x no screw points protruding into wiring channels

x socket brackets aligned with fixture body

x socket brackets solidly attached

x socket firmly attached to bracket

x reflectors aligned with fixture axis

x reflector easily removable

x lamp/reflector clearance > 0.25 inch

x lamp replacement not impeded

x lens removal not impeded

x lens uniformly illuminated without shadows

The prototype installation can also be used to compare the average illuminance beforeand after modification. This may be used to qualify the reflector by ensuring that astated minimum percentage of the original (cleaned and relamped) illuminance isobtained after retrofit.

Maintenance

A reflector will only need to be removed to replace a failed ballast, a relatively rareoccurrence. Nevertheless, reflectors should still be easy to remove and replace.

Although claims have been made that static electric effects will keep the specularreflector cleaner than the reflector it replaces, it is prudent to assume that the LDD isthe same. A reflectorized luminaire will require less maintenance because it has fewerlamps and ballasts. But the reflective surface should be cleaned according tomanufacturer's instructions frequently enough to maintain the required light levels.


3-50

This will probably be more often than before, because the room is no longeroverlighted.

Group relamping is another technique that will help maintain the desired light outputfrom a reflectorized luminaire because group relamping ensures that fresh (non-depreciated) lamps are more often in place.

When to Use Reflectors

If you are not changing lamps/ballasts, locate spaces in your building that areoverlighted and can tolerate operating at 60–75% of current illuminance. You candetermine the existing lighting level using either the lumen method of calculation, orby measurements in a typical space that is cleaned and relamped. If your retrofitincludes replacing lamps/ballasts, then you should consider reflectors even in spacesthat are not overlighted, as you can choose a lamp/ballast combination that willprovide equal or better illumination from the delamped luminaire.

Kits

Retrofits are sufficiently common that reflector manufacturers have standardized themost popular products into “kits.” Kits are generally well-developed products thatreduce installation time and cost and combine reflectors or other retrofit technologieswith the most often required components to make the retrofit complete.

Take for example the most common retrofit: delamping a 2’x 4’ lens troffer to twolamps, using a combination of a reflector to increase luminaire efficiency and T-8 lampsand electronic ballasts to produce a much lower-wattage fixture and acceptable lightinglevels. This retrofit involves these actual steps:

1. Remove lens and set aside to be cleaned and reinstalled (or replaced).

2. Strip out all fixture “guts,” including lamp sockets, socket wires, socket mountingbrackets (“bridges”), and ballast.

3. Install new ballast and connect to power source.

4. Install new socket bridges, sockets, and wiring.

5. Connect socket wires to ballast.

6. Install reflector.

7. Install new lamps.

8. Clean and reinstall lens.


3-51

A well designed “kit” usually includes some combination of reflector, socket bridge(s),prewired sockets, and ballast, designed to install quickly into a gutted luminaire,combining most of steps 3, 4, 5, and 6. The technician positions the “kit,” fastens it inposition with self drilling “tek” screws, lowers the hinged access, connects power to theballast, raises the hinged portion back in place, and installs the lens. Labor savingssignificantly outweighs the additional cost of the kit.

Figure 3-11 Typical Retrofit Kit for 2x4 Troffer

Kits can also be made of retrofits not involving reflectors. One such common kit isdesigned for replacing two 8-foot F96T12 slimline lamps with four 4-foot lamps and anelectronic ballast. This kit is often used for industrial and commercial strip lights,resulting in reduced power, longer lamp life, and lower lamp cost. In some kits theballast compartment cover is hinged to allow quicker installation by one person.

Even though there are thousands of different fixture designs that are candidates forretrofitting, most of these fixture types have been retrofitted before and the retrofit andreflector companies have developed patterns for them. Now, the features of a kit arereadily made into a product designed specifically for the luminaire being retrofitted.


3-52

Table 3-19Retrofitting Lenses

Lens Type Description Probable Reason For Original Use Typical Coefficient of Utilization(CU)*

Standard Pattern 12 Diagonal pattern of femaleconical prisms

Generic, most common style 76%

Pattern 15 Square pattern femaleconical prisms

Lens upgrade to improve appearance 72%

Pattern 19 Diagonal patterns of maleconical prisms

Lens upgrade to improve appearance 72%

Pattern 11 Louver lens Upgrade to incorporate appearance oflouver with lens performance

62%

Diffuser White sheet acrylic Appearance 57%

Cracked Ice Unpatterned crystals Appearance 63%

*Coefficient of utilization based on a nominal 2x4 size troffer with 4 lamps. The room cavity ratio (RCR) is assumed to be is typical forlarge rooms. Reflectances are assumed to be 80/50/20 for the ceiling, walls, and floor, respectively.

Lenses

Most lighting lenses are made of high-quality, UV-stable acrylic, and maintain theirclarity over many years. Obvious yellowed lenses are inferior products made of styreneor other plastic which is not UV-stable, and should be replaced without question.

Older acrylic lenses, while appearing still fairly “clear,” actually have 15% lesstransmission and should be replaced every 10 years. New lenses, in addition torecovering dirt depreciation, will give higher lighting levels due to high transmission.The low cost of a replacement lens, in lieu of cleaning, should be considered for everyretrofit of older lighting systems. Replacement lenses are available for virtually allfixture types, including troffers, wraparounds, and other styles. At a minimum,replacement of broken lenses should be part of a retrofit program.

Some lenses and most diffusers are inefficient compared to the common “pattern 12”prismatic lens used in most troffers. As a retrofit, consider changing to the everydaypattern 12 prismatic. The specific photometric effects of certain esoteric patterns areoften lost on modern lighting situations (except VDT’s—see below). Be especiallycertain to replace milky white diffusers, “cracked ice,” and other unusual lenses withprismatic lenses in most situations, as fixture efficiency will increase dramatically.

Special Retrofit Lenses

There are a few special lens products that increase luminaire efficiency andeffectiveness. The most popular of these products is a lens that can be readily


3-53

recognized by its unique varying patterns of conical and linear lenses. Two-lamp andthree-lamp lenses are made, the two-lamp being a popular alternative to reflectorswhen delamping. As opposed to the reflector retrofit, which improves luminaireefficiency by improving the reflectivity of the luminaire cavity and decreasing thenumber of inter-reflections, the lens increases luminaire efficiency by being optimizedfor the luminaire box and lamps. Expect similar results as with reflectors, but expectmuch different appearance. This type of retrofit lens increases high angle refraction,causing greater perceived brightness and upper wall illumination, therefore increasingglare in many VDT applications.

Changing Lenses for VDT Spaces

Since many retrofits will be for offices and other spaces with computer use, replacingordinary lenses with products more suited for the task is possible. The followingoptions are available for flat lens troffers (mostly 2’x 4’, 1’x 4’ and 2’x 2’ troffers):

x premium versions of traditional conical prism lenses, usually with silver tinting orother means of reducing high angle brightness. Be cautious of some inexpensive(usually thin) lenses which can sag below the luminaire opening, causing excessiveglare

x special “computer friendly” lenses, generally using many small round “lenses” todirect light into the zone where minimal computer interference can be expected

x thin louver panels, often called “egg-crates” or “paracubes,” usually 1/2” thick,consisting of many 1/2” x 1/2” parabolic cells of metalized plastic

x thicker louver panels, up to 1½” thick, similar to the above but with cells up to 3”x3”

x full-sized parabolic louvers in chassis designed to sit under existing troffers (thetroffer’s lens is removed and the troffer is then lifted up and the louver assemblyplaced underneath so that the troffer can sit on it)

In general, reflectors can be used with most VDT-compatible louvers, but with varyingdegrees of success. Reflectors are not compatible with special “VDT friendly” lenses butcan be used with premium standard lenses.

Most lens and louver manufacturers can supply photometric data for their productswith and without reflectors in a representative luminaire. Use these data in LightPad orother analysis tools to determine whether a reflector should be used with retrofit lensesor louvers. Do not be surprised if the resulting calculation does not recommend areflector, because the retrofit lens can reduce the illumination so low that a reflector’slight reduction is unacceptable.


3-54

Design Considerations—Lenses and Louvers

In fluorescent lighting systems, the lens or louver affects not only the light quantity andquality, but also key psychological perceptions of the lighting system. When retrofittingthese systems, take the following into consideration.

1. Plastic lenses tend to appear utilitarian and “institutional.” Appearanceimprovements, even minor, will make a space feel more upscale, generally ofpositive benefit. Louvers are considered a significant quality upgrade.

2. Lenses—especially retrofit lens products—increase high-angle illumination andmake a space appear brighter. Louvers tend to decrease upper wall light, creatingmore dark-appearing or cave-like spaces. The lenses may seem desirable butcomputer work spaces often are better lighted by the louver.

3. Large-cell louvers and efficient lenses transmit light most efficiently. Small-celllouvers and special lenses produce light less efficiently. When considering a retrofit,use an efficient lens or louver. If inadequate light is produced, consider a reflector incombination with the lens change.

Control Technologies

This section presents information on general control technologies to consider in retrofitapplications.

Retrofitting Occupancy Sensors

Occupant sensors may be used to control lighting based on the occupancy of a space.They are good retrofit options when spaces are used intermittently.

Sensor Technology

Devices that switch lights on or off based on detection of motion within a specific roomor area are called “occupancy sensors.” There are several different types, each withadvantages and features making it more applicable to certain room types and uses.

Occupancy sensors are available in both self-contained devices and as part of morecomplex systems. Self-contained occupancy sensors are generally wall-mounted in lieuof a standard switch. Devices that require manual activation and devices that turnlights on automatically are available, some offering both options by means of a switch.Devices connected into systems can be wallbox, upper wall, or ceiling mounted, withwiring to the actual switching device (transformer-relay). Systems permit multipledetectors controlling the same lights, covering a larger area with greater sensitivity.


3-55

Table 3-20Occupancy Sensor Types

Wallbox Sensor

x used in place of a standard switch

x for small rooms like private offices

x completely self-contained

x time-out warning

x adjustments under plate

x manual on/auto off or switchablemanual/auto on

Ceiling Sensor

x up to 360° detection

x self-contained or connect totransformer-relay or large system

x interconnect several sensors to coverany sized room

x adjustments on case

x time-out warning

High Wall And Corner Sensors

x often optimal viewing angle

x especially good for corridors andlarger rooms

x connect to transformer relay or largesystem


x time-out warning

Portable And “Personal” Sensors

x designed to be in front of worker todetect small motions

x time-out warning


x connects to plug strip

x switches any load, e.g. task light,printer, etc.

There are two primary technologies used in sensor design. Passive infrared (PIR)sensors respond to motion of warm-bodied objects between small visual windows inthe sensor’s electric eye. Active ultrasonic sensors emit a field of ultrasound and detectreflections having different frequency, indicating motion by the Doppler effect. PIRsensors are less expensive, but are unable to detect occupants shielded by partitions orother obstructions. Also, there are gaps in coverage for PIR sensors at distances greaterthan 15–20 ft. Ultrasonic sensors overcome some of these deficiencies, but can pick upfalse signals such as air movement from HVAC systems or open windows. Somesensors employ both technologies as each has certain advantages over the other.

Primary design considerations for occupancy (motion) sensors

1. Choose a sensor type suitable for the room. The least costly devices—usuallywallbox PIR switches—are not sensitive to small motions by an occupant workingwith his/her back to the sensor, as with a computer.

2. Take furniture and other objects in the room into account.


3-56

3. Choose manual “on” to encourage maximum energy consciousness, but automatic“on” in hallways, rest rooms, common work rooms, etc. as a convenience.

4. There are differing means of time-out warning, and some devices will respondbetter to an unwanted “off.”

Applying Occupancy Sensors to Existing Buildings

Wallbox Sensors. The easiest sensors to install replace manual wall switches. Ascompared to a building with only manual switches, wallbox occupancy sensors can beexpected to save 10–50% of the energy used by lighting, the actual savings beingheavily dependent on building occupancy and use patterns.

Wallbox switch sensors are limited to use in small to medium-sized rooms. Largerrooms need different detectors and often multiple detectors. Wallbox sensors oftenrequire three-wire (hot-switched hot-neutral) connections in order to control smallloads, such as a single luminaire. Two-wire sensors, which are easier to install,generally require a much larger load.

Sensors with Remote Transformer Relay (“Power Pack”). Sensors to be mounted inoptimum ceiling or wall locations and rooms with multiple sensors will generallyutilize a power pack containing the transformer to power the sensor’s low-voltagecircuits and a relay to switch the lighting power. The power pack is located onto ajunction box generally already in place to feed the lights to be controlled. Sometimes ajunction box may need to be added or other provisions made. Wiring to the sensor(s) isusually via low-voltage multiconductor cable that can be surface mounted, run inconduit or, if the cable is plenum rated, run exposed above an accessible ceiling.

Sensors Signaling Larger Systems. Sensors can be used to signal larger panel relaysystems, building automation systems and energy management systems. Buildingswith existing systems of these types might be able to have sensor inputs added as“manual override” zones in lieu of, or in addition to, low-voltage manual switches.New systems being added to buildings generally have special inputs and controlfeatures optimized for sensors. As with power-pack sensor applications, wiringbetween the sensor and the system is typically low-voltage, multiconductor cable.

Personal Workstation Occupancy Sensor. For office workstations and similarapplications, a single outlet or plug strip with a remote motion sensor can be used tocontrol task lights, computer peripherals, and space heaters (within the power striprating, 15 amps for one manufacturer).


3-57

Figure 3-12 Occupancy Sensor/Powerstrip

The motion sensor may be mounted under a shelf facing the occupant, or be free-standing and moved around by the occupant, for instance next to a computer keyboard.The sensor connects to the outlet or power strip with a telephone-type connector cable.

Some models have individual switches in the sensor unit for manual on-off control ofthe several outlet types. Systems of this type are very easily added to existingworkstations with essentially all surface wiring or wiring within the panel system.

Dimming Controls

Many lighting systems can be dimmed, reducing power to save energy and demand.Dimming can occur constantly or during specific periods of use.

Dimming Strategies

Daylighting. Interior (and some exterior) spaces are sufficiently illuminated by naturaldaylight not to need electric light. However, changes in natural light over the course ofthe day, as well as constant changes due to weather, would generally cause distractinglight switching. Dimming electric lights continuously based on photosensor signals canmake the electric lighting system changes unnoticeable to space users.

Adaptation Compensation. Many facilities properly lighted by day will be overlightedby night. For instance, in the center of a tunnel, light is needed by day to allow thedriver to see because his/her eyes are adapted for bright daylight. The same tunnellights could be dimmed considerably by night. Similar opportunities exist in all typesof facilities, from hotels to grocery stores.

Lumen Maintenance. Lumen maintenance systems save the excess energy used by newor recently-replaced lighting systems by slightly increasing lighting power over the


3-58

lighting systems’ maintenance period until full power is only used just beforemaintenance should occur.

Tuning. Many lighting systems provide more light than needed. A minor reduction inlighting (up to about 25%) will not be noticed and for most workers will not reduceproductivity. Especially with fluorescent lighting systems, this translates into a direct25% power and energy reduction.

Manual Dimming. Either in addition to or in lieu of tuning, providing workers withthe choice of lighting level can often result in lower energy consumption.

Demand Limiting. A small amount of lighting dimming initiated by a facility-widemanagement system can be used to help flatten a power demand curve to reducedemand kW costs.

Incandescent. Incandescent lights can be dimmed easily using either standard solid-state dimmers or autotransformer dimmers. Many different types of incandescentdimming systems are available. Because of the low cost and ease of dimming,incandescent dimming is popular in most settings. However, the relationship ofincandescent light to power is not linear, and a lamp dimmed to 50% lumen outputconsumes 78% of its rated energy. Dimming incandescent lighting to save energy thushas extremely modest potential and should be considered only after other options havebeen evaluated.

Fluorescent. Full-size, U-bent, and compact fluorescent lamps can be dimmedeffectively and with significant potential for energy savings. Methods of dimminginclude:

x electronic ballast with internal dimming circuits whose action is controlled by anexternal signal (This is by far the most recommended method.)

x dimming magnetic ballast whose input power is regulated by a dimmer similar toan incandescent dimmer

x non-dimming magnetic ballast whose input power is regulated by a special type ofdimmer or an autotransformer

x reduced light output at fixed amounts using stepped ballasts or devices formagnetic ballasts which modify the impedance of the lamp arc circuit (powerreducers or current limiters)


3-59

Figure 3-13 Effectiveness of Dimmers at Saving Energy

Fluorescent light and power are almost linear between about 100% and 20% forelectronic ballast dimming. Below 20%, decreasing light reduces power less. As aresult, most electronic dimming ballasts have a minimum of 10–20%. However, someelectronic ballasts intended for “architectural” dimming applications can dim to as lowas 1% or less of rated lamp light without flickering.

Other methods of fluorescent lamp dimming, especially any method using ordinarymagnetic ballasts, should be pursued carefully as reduced energy efficiency, short lamplife and limited dimming capabilities are common risks.

High Intensity Discharge (HID)

Of the modern light sources, HID lamps are probably the most expensive and leastdesirable to dim. Dimming impacts proper lamp arc temperature and pressure, whichcauses efficacy to drop and color to shift. Short lamp life can also result.

However, there are a few specific systems designed for HID dimming applicationswhich, in addition to minimizing these problems, provide meaningful energy savingswith few drawbacks. The key to their use is limiting applications to spaces where colorrendition is not important, such as industrial, warehousing, and transit facilities.


3-60

Re-Wiring

Most dimming methods will require the addition of wires to carry the control signals,as well as the control generating signals from photosensors and other devices. Recentdevelopments in electronic ballast design allow for dimming to be controlled usingexisting two-wire circuits by replacing an existing wall switch with an incandescentdimmer. Another product uses low-voltage cables exclusively for controls, permittingexisting power wiring to be left intact.

Timers and Time Clocks

Timers are devices that activate lights for predictable periods of time. Although simplein concept and insensitive to occupancy, timers serve a valuable function by assuringan absolute cessation of lighting operation without further user input. Time clocks aretraditional scheduling devices for energizing lights for predetermined periods on aregular basis. Both cost less and are easier to install than other control devices.

Mechanical Timers

Mechanical timers utilize a wound spring to measure time and open the circuit after apredetermined period. The range of the device (e.g. 0–15 minutes) is fixed by theswitch mechanics. Rating is usually 15 amps at 120 volts.

Figure 3-14 Mechanical Twist Timer

Electronic Timers

Electronic timers allow changing of the time period and generally have tap-on control.In addition to more modern appearance and tactile response than mechanical timers,


3-61

electronic timers have an accurate electronic time readout and optional time-outwarning.

Figure 3-15 Electronic Touch Timer

Programmable “Time Clocks”

The redundant expression “time clock” has been used for decades to describe electricclock mechanisms with mechanical dials having trippers to open or close a mechanicalair-gap switch. More recently, electronic devices have become popular as well.

A mechanical time switch is a device having an integral 120-volt motor-operated clockand an air gap switch operated by trippers attached to the clock face. Portable plug-indevices as well as wall box mounted devices are sold. Larger devices enclosed ininterior and exterior NEMA boxes are also made. Typical mechanical devices generallycan control two 40-amp circuits. Electronic clock package units are now availablecontrolling up to eight independent 20-amp circuits each having different timeschedules. Inexpensive mechanical devices are invariably 24-hour schedule devices, butthe larger mechanical units and most electronic units can also include such features as7-day calendar clocks and “astronomical” dials, clocks which are (theoretically) able tocompensate for the change of seasons.


3-62

Figure 3-16 Programmable Time Clock

Applying Timers and Time Clocks to Existing Buildings

Timers generally replace wall switches directly. Time clocks are generally added in thepower circuit feeding the lights, often in a utility location such as an electric closet ormechanical room. Because time clocks seldom have an associated wall switch or otherneed for user access, installing time clocks is generally easy and often occurs adjacent tothe panel feeding the lights.

Powerline Carrier Controls

Despite the continuing increase in the amount and type of high-harmonic content loadsin buildings, makers of powerline carrier systems believe that modern digitalcommunications technology can overcome the problems of prior analog designs andpermit widespread use of powerline carriers in most buildings. Products are presentlyunder development that show definite promise. Until these systems are available,knowledgeable designers can still consider powerline carrier systems, analog or digital,provided specific considerations are made:

1. Loads that generate harmonics or other spurious signals in the band(s) used by thesystem need to be isolated and filtered or removed. For instance, some “wirelessintercom” systems use powerline communications and can effectively block thepowerline medium to the control signals.

2. Loads which “short out” high frequency signals may need to be isolated orchanged. Power factor correction capacitors and certain very low harmonicelectronic ballasts diminish the control signal, making it difficult to be receiveddown line.

3. Amplifiers, signal repeaters, and coupling bridges need to be added throughout thesystem.


3-63

Photocells

“Photocells” are switching devices to turn lights on or off according to the amount oflight striking the sensor (photocell) surface. Most photocells are designed for switchingoutdoor lighting at dawn and dusk. A hysteresis and time delay circuit is built in toprevent nuisance switching and “chattering” when incident light is at or near theswitching point. Most photocells are not adjustable. Outdoor photocells can bemounted onto fixtures or can be separately mounted on a building roof or otherlocation.

There are a few photocells designed for indoor use. They generally have some sort ofadjustment, usually mechanical, although there are an increasing number of deviceswith electronic adjustments. Many such devices are part of an occupancy sensordesigned for ceiling or wallbox use.

Photocells are designed to be rugged, reliable, low cost, and fairly uniform inperformance. There are very few options. All photocells are designed for open-loopapplications; so they must not sense the light created by the fixtures being controlled.

Photosensors

Photosensors are devices that create continuously varying analog outputs designed tointerface with fluorescent dimming electronic ballasts in energy managementapplications. Most photosensors have adjustments similar to occupancy sensors,including time delay, response speed, and sensitivity.

Most photosensors were made and sold as part of a system by the manufacturer of thedimming ballast. Photosensors sold as part of a system may communicate with thedimming ballasts in a number of ways, including 0–10 VDC analog signal, pulse-width(duty cycle) modulation and AC wave conduction angle.

There are, however, a growing number of generic photosensors. These photosensorscreate analog signals compatible with electronic ballasts that utilize a 0–10 VDC signalto determine light output.

Considerations of photosensor applications include:

x Setting sensitivity includes setting the low end and high end (range), which can bedifficult and require considerable patience.

x The sensor generally must be protected from direct viewing of the sun and brightsky.

x The sensor looks at the light being created by the luminaires it controls and shouldbe located to look at the task area or otherwise follow manufacturer’s installation


3-64

recommendations, avoiding looking at non-task areas and other parts of the spacethat can create misleading or incorrect signals.

x Sensor response can be affected by the number of ballasts connected to it.

x Sensors can be sensitive to bright areas within the zone, such as a person enteringthe space wearing white clothing or the work surface being covered by a large pieceof paper. The bright zone sensitivity of photosensors on the market varies widely.

To take full advantage of the photoelectric control strategies of daylighting, lumenmaintenance and adaptation compensation, system performance including both thephotosensor(s) and ballast(s) will probably best be optimized by a system from a singlesource supplier who can best match products, make critical adjustments, and even addcomponents. Many manufacturers are taking this point of view, and their ballasts aregenerally not for sale or intended to be used with generic photosensors. But suchsystems can limit competition and increase cost, especially for small projects.

On the other hand, now that all of the major manufacturers of electronic ballasts areoffering reliable, competitively priced dimming ballasts with at least a 20–100%dimming range, the race is on to develop low cost, high performance genericphotosensors. The competition between the two viewpoints is expected to be fierce.

Latching Switches

A “sentry” switch is an electro-mechanical latching relay with toggle switch activation.It is designed to replace ordinary toggle switches and appears similar in appearance.

The sentry switch operates as follows: by activating the switch, a latching relay circuitin the switch body is closed, providing continuous power to lights. Deactivating theswitch manually results in lights being extinguished, as the user would expect. But thekey to the sentry switch’s importance is that, if power is interrupted to it, the switchresets to the “off” position automatically.

Sentry switches permit the use of relays and contactors in electrical closets and otherremote locations to “sweep” off building power by briefly turning lighting circuits off,then on. The sentry switches reset to “off,” and those needing lights can simply turntheir lights back on without all lights on the circuit being energized.

Sentry switches are the least expensive way of retrofitting an existing building withswitches in every room to an automatic time-of-day shut-off control having maximumsavings. The interruption to workers may or may not be acceptable.

4-1

4 LIGHTING SYSTEM TYPES

This chapter addresses common retrofit opportunities for general lighting system types.Lighting system types are organized in three general categories: commercial, industrial,and outdoor. The table below expands on these general categories.

For each of these categories, we will include a description, illustrations, and adiscussion of retrofit options with a guidelines for assessing the options.

General Commercial

General Commercial Lighting Systems

Commercial lighting includes the lighting systems used in office buildings, institutions,stores, schools, and all other nonindustrial, nonresidential buildings. This lightingconstitutes almost 50% of the electric lighting load in the United States. Most of theselighting systems were based on the F40 fluorescent lamp; and while their designs andmaterials have evolved over the last 50 years, even the most modern products bearconsiderable resemblance to the oldest fluorescent products. The remainder ofcommercial lighting systems tend to be based on incandescent lighting and includecommon styles such as downlights and many different decorative fixtures.

Because most commercial general lighting is based on the four-foot T-12 lamp and itsrelatives, a majority of these lighting systems can be retrofit easily and cost-effectively.Other lighting systems, such as retail lighting systems, also enjoy the potential forimpressive savings and payback.

For retrofitting, commercial lighting is the largest opportunity. The most commonretrofits include T-8 lamp and electronic ballast conversions, which, due to their vastpopularity and success, have resulted in extremely low material costs and theprobability of cost-effectiveness in most applications. Similarly, conversions ofincandescent luminaires to compact fluorescent have also become quite cost-effective asvolume has driven down prices and encouraged the development of clever labor-saving products and procedures. The vast number of retrofits of these lighting systemstypes assures successful results in most situations.

Lighting System Types

4-2

Table 4-1Lighting System Types

Category Lighting System Type Notes

General Commercial Fluorescent Troffers Probably the most common

Downlights Very common, also wallwashers, accent lights, etc.

Fluorescent (non-troffers) Wrap-arounds, direct/indirect, pendant-mounted, covelights, undershelf, medical

Decorative and Utility Lighting Chandeliers, pendants, sconces, table, and floor lamps,etc.

Exit Signs

Track Lighting

Industrial Fluorescent

High Bay

Low Bay

Vaportight

Watertight

Special Purposes/Environments Prisons, caustic, explosive, etc.

Outdoor Roadway and Parking Lots

Floodlights

Security

Decorative

Landscaping

Fluorescent Troffers

The fluorescent "troffer" is the most common type of commercial lighting system. Mosttroffers utilize some form of flat plastic or glass "lens" or diffuser as the shielding andrefracting medium. In some cases, small-cell louver panels, sometimes called "egg-crate" or "paracube" louvers, have been installed in place of the lens. After about 1980,the larger "parabolic" louvered fixtures became increasingly popular (see separatestandard). Still, the lens troffer is the commonest recessed fluorescent lighting producttype manufactured.

Troffer lighting systems are excellent lighting retrofit opportunities. Without changingillumination levels, lighting power demand and energy can often be reduced up to40%; with an acceptable lighting level reduction, power demand and energy savingscan be 60% or more. A wide range of products is available to make conversions withacceptable payback periods.

General Information

Support. The troffer is designed to lay into a tee-bar acoustic tile suspended ceilingsystem, making it an integral component of the most inexpensive complete ceiling-lighting-HVAC system used in commercial construction today. There are a number of


4-3

different standard grids, each having specific dimensions and for which small butimportant differences in troffer dimensions are apparent. Independent structuralsuspension is required in California and other locations, particularly for earthquakeresistance.

HVAC Coupling. Troffers can be sealed boxes ("static") or can serve as part of thebuilding's HVAC delivery system.

x Heat Extract troffers allow return air to be removed through the troffer into a returnceiling plenum, especially by passing air past the lamps. Heat extraction helps coolthe fluorescent lamps to a near-optimum temperature, thereby generatingmaximum light. Heat extraction was extremely important for four-lamp T-12troffers but is relatively unimportant in electronic T-8 systems.

x Air Supply and/or Air Return troffers employ a thin air slot all around the lens. Theslot is connected to an HVAC system "boot" that in turn is connected to either asupply or return duct.

x Some troffers are shipped with all options and certain field adjustments allow theluminaire to assume any of these configurations.

Shielding Media (Lenses and Louvers). The most common shielding medium is a flatplastic panel comprised of small prisms, often called a prismatic lens. Although manydifferent types have been developed, the most common is the "pattern 12," acheckerboard pattern of conical prisms. Pattern numbers were assigned by KSH (nowICI Acrylics), a leading developer of lighting media.

Other shielding media include:

x Other prismatic lens types, including square prisms, linear prisms, etc. Some ofthese lenses may be tinted, which reduces brightness but reduces glare as well.

x Egg-crate louvers, either white or metalized up to 3/4" thick

x Flat and drop milky plastic diffusers

x Special types of lenses such as "bubble" elements and non-homogeneous prismaticpatterns

x Multilayer polarizing panels

Lens thickness affects appearance and sag. The industry standard for the pattern 12lens is .110" thick, although specifiers prefer .125" and cheap lenses are .100". Lensesshould be made of lighting-grade, UV-stabilized virgin acrylic. Yellowing of lenses orplastic louvers indicates use of polystyrene or other non–UV-stable materials.

The lens or louver is usually held in a door with hinges on one long side to allow accessto the lamps. Doors may be steel or aluminum, flat or regressed, and butt-joined or


4-4

mitered in the corners. In some very inexpensive luminaires, the lens may be enclosedin a lightweight frame that utilizes a lift-and-shift access to the lamps.

Internal Reflecting Surfaces. Most troffers employ baked white enamel paint on theinterior reflecting surfaces. White enamel degrades over time, losing reflectivity in theprocess. Enamel paint is about 80–85% total reflectivity. Porcelain was also used inpremium products, but is not significantly different from white enamel paint. Currentproducts may use polyester powder coat paint with 90% or higher total reflectivity andbetter UV stability.

Lamps and Ballasts. Most troffers were designed for F40T12 rapid start fluorescentlamps, including the 2'x 4', 1'x 4', 4'x 4', 20"x 4', and some 5' long units. The 2'x 2' trofferswere designed either for the FB40T12 U-lamps or the F20T12 straight lamps. The 3'x 3'units usually used F30T12 lamps, although there were also some using diagonal F40T12lamps. Some new fixtures (and those retrofit) may have FO32 (T-8) lamps. Rarely, onemay find slimline (F48T12) or high output (F48T12/HO) lamps.

Ballasts are located in compartments, generally accessible from the interior of theluminaire. However, some products may have outboard ballast compartments,especially to one side to make for a shallower troffer. Existing fixtures in most of theUnited States originally installed prior to 1990 (prior to 1982 in California) may beassumed to have standard or non-energy saving ballasts as original equipment.

Retrofit Opportunities

General Considerations. The ability to reduce energy in troffer retrofits is a function ofreducing power as much as reasonably possible. Consider all of the following inselecting a retrofit program:

x General layout (square feet per fixture). The coverage area per luminaire is critical indetermining design lighting level, new lighting level, and any opportunities forintentional lighting level reduction.

x Room surface finishes. Rooms with dark surfaces must be lightened wheneverpossible, including ceiling tile replacement where existing tiles are soiled or notfairly white. Dark finishes can act as light absorbers capable of causing 20–30% lightlevel reduction in smaller rooms as compared to lighter finishes. Recoveringlighting level by painting rooms or replacing ceiling tiles allows as much as 25% lesslighting power than a dark room and is a critical potential energy conservingelement of a DSM program.

x Lighting level. Reduce lighting levels to appropriate levels if the space is overlighted.

Reflectors. The most widely advertised retrofit product is a new internal reflectingsurface for the luminaire. Although much of the advertising is technically misleading,


4-5

retrofit reflecting surfaces can be effective in certain luminaires when combined with apower reduction strategy such as delamping and/or T-8 lamp and electronic ballastconversion. There are three primary retrofit reflector types:

x specular (shiny) high-purity aluminum, having a total reflectivity of 88–92%, andformed into an imaging faceted reflecting surface

x specular silver on substrate, having a total reflectivity of as high as 94%, also formedinto an imaging faceted reflecting surface

x white polyester powder coat paint on steel or aluminum, having a total reflectivityof about 90%, formed into a simple semi-diffuse reflecting surface

Specular imaging reflectors are designed to reflect mirror images of the lamp's sidesdirectly onto the lens, thereby eliminating multiple interior bounces for each light ray.In deep fixtures (aperture to reflecting surface 4.5" or greater) significant efficiencybenefits are achieved through the use of imaging reflectors regardless of the conditionof the original reflecting surface. In shallow fixtures, especially with well-maintained ornew white painted reflecting surfaces, the benefits of imaging are minor.

Silver specular reflectors should only be used when supplied by a major company andbacked by a 10-year warranty. High purity premium specular aluminum reflectorswith 20–25 year warranties are generally preferred due to lower cost. Specular imagingreflectors should only be used in deep troffers, or in conjunction with metalized egg-crate or "paracube" louvers. White polyester powdercoat reflectors may be used insituations where a shallower luminaire has an aged or deteriorated reflecting surface.

Lenses and Louvers. Any lens or louver appearing brown or yellow should bereplaced. This discoloration is a sign of UV degradation and/or age, and reveals asurface whose efficiency has fallen by 30–60%. Also, any lens over 10 years old shouldalso be replaced; although not apparent, its transmitting efficiency has also degradedby as much as 15%. In most cases, a new pattern 12 acrylic prismatic lens will beadequate.

It is possible to retrofit lens luminaires in VDT workspaces to meet modern computerscreen standards. In most troffers, this upgrade occurs with either:

x one of several acrylic lens products designed for VDT applications, with or withoutwhite powder coat reflector retrofit; or

x a paracube louver with or without specular imaging reflector retrofit


4-6

Table 4-2Recommended Illumination Levels

Space Type Recommended Illumination Level 1 Measurement Conditions

General Office Space 60 fc empty room, initial

Computer Office Space(task lighting should be added)

40 fc empty room, initial

Conference Rooms, Lobbies 40 fc empty room, initial

Classrooms 60 fc empty room, initial

Major Hallways, Corridors 20 fc empty room, initial

Grocery Stores 75 fc empty room, maintained2

Industrial/Commercial Work Areas(task lighting should be considered)

50 fc empty room, initial

Retail Stores with Separate Track or DisplayLighting(display lighting is assumed)

40-60 fc empty room, initial

1 Maintained illumination will be 15 to 20% lower than the initial illumination recommendations in this column (except for groceries)

2 Maintained lighting level is a highly debatable issue, especially in grocery markets where lamp life can exceed 30,000 hours.Because fluorescent lamp lumen depreciation is a function of operating hours and not number of starts or average hours per start, itis tempting for the grocer to leave lamps in place as long as possible. Designing for a minimum maintained lighting level assumingsuch lamp life will result in systems using excessive initial energy. Unless lumen maintenance dimming equipment is employed, i t isrecommended that an economic break-point be determined as a function of lamp and relamping cost as compared to excessiveenergy consumption cost.

Since VDT-compatible lighting should also be at a slightly lower illumination level thanstandard office lighting, often lighting systems can be upgraded within the economicsof a DSM retrofit project. However, even if the economics do not work out, manyclients will consider paying extra for the upgrade.

Lamps and Ballasts. Since most troffers employ T-12 bi-pin lamps, there is almostalways a direct T-8 substitute which will fit the existing sockets (called "tombstones").Tombstones should be replaced if they are relocated or if they appear cracked orotherwise broken; otherwise, replacing tombstones is probably not necessary. Thenumber and type of T-8 lamp should be determined as set forth below.

When converting from T-12 to T-8 lamps, conversion to electronic ballasts is standardprocedure. (see the Retrofit Technologies chapter.) The number of lamps operated perballast should be maximized, replace two two-lamp ballasts with a single four-lampballast. However, adjustments should be considered to accommodate switching, suchas separate daylighted zone controls or multilevel (master-slave) switching.

Occasionally, converting from a U-bent T-12 lamp to straight FO17T8 lamps makessense. Kits that include the new sockets, ballast covers and wireways are standardproducts with or without a reflector.


4-7

Delamping. Many of the best retrofit programs involve some form of delamping toreduce power. This is in part possible because older lighting systems tend to beoverdesigned by modern standards. For example, one of the most popular lightinglayouts employs four-lamp F40T12/ES lens troffers on 8'x 8' spacing. Usingconventional cool white energy-saving lamps and magnetic energy-saving ballasts, thissystem produces about 85 initial foot-candles, average, in the average private office andabout 105 initial foot-candles in an open office area at 2.25 watts per square foot. Part ofthe opportunity for energy savings is to reduce the lighting level and its power throughdelamping.

However, delamping does not necessarily imply the use of retrofit reflectors. In manycases, delamping and relocating the tombstones, combined with T-8 /electronic ballastconversion, luminaire cleaning, and a new lens, will provide satisfactory results.

Choosing a Retrofit Package. The best retrofit will be the one providing necessaryillumination with the best payback on the investment (including the benefit of theutility rebate, if any).

If luminaires can be moved around easily and without concern for asbestos, structuralintegrity, HVAC connection, or other limitations, assuming ceilings up to 10 feet high, ageneral program of two-lamp luminaires on 8' x 8' centers is recommended. This allowsa variety of ballasts, lenses, and reflecting media to be used to accomplish the bestpossible result. However, it is generally anticipated that luminaire relocation will notbe feasible for most projects.

Therefore, the following selection process is recommended:

1. Establish the desired foot-candle level, which can vary from room to room.

2. Based on the luminaires in place, select options that provide the desired initial foot-candle level, plus-or-minus 10%. There will be a number of options in many cases.

3. Determine the cost, energy savings, rebate, and payback for each option. Someoptions use less energy than others, but probably cost more. Make certain to obtainprices from corporate purchasing on key items like electronic ballasts, T-8 lamps,high performance lenses, and other standard components. At this time, reflectorsare to be purchased locally.

4. Select the most desirable option under the project's circumstances. This will be anacceptable solution for all parties.

Incandescent Downlights

Downlights are the most common family of architectural luminaires, includingwallwashers and accent lights. Often called “cans” or “tophats,” downlights aredesigned to throw light downward from the ceiling. Most downlights are round and


4-8

are recessed into gypsum wallboard, acoustical tile, or other types of finished ceilings.However, there are also square downlights and surface-mounted types. The mostcommon uses of downlights include lobbies, corridors, meeting and conference rooms,auditoriums, theaters, and highly finished spaces such as executive office areas,restaurants, or hotels.

The vast majority of downlights use incandescent lamps. However, there are a smallnumber of HID downlights in use, and a growing number of compact fluorescentdownlights, especially in new construction in states with significant energy codes. Boththe incandescent and HID downlights offer retrofit opportunities.

General Information

Types of Downlights. To assess the retrofit opportunity properly, it is important tounderstand the types of downlights, which vary significantly by application and optics.

x Open “R” lamp with baffle trim. Estimated to be the most commonly occurringdownlight, and used for general illumination in many building types, the blackbaffle R lamp downlight is used for general illumination only. The objective of theblack baffle is to reduce glare. When used for general illumination in ceilings lessthan 12 feet, it can usually be retrofitted with hardwired or screw-in compactfluorescents as described later in this handbook.

x PAR lamp black baffle. Similar to open R lamps, PAR lamps are generally installed inhigher ceilings. The candlepower of the PAR-38 lamp is used for generalillumination in higher ceilings, typically above 12 feet and perhaps as high as 20feet. The largest lamp is usually Q250/PAR-38. Compact fluorescent or HID retrofitsmay be appropriate, but will depend on the application.

x R and PAR downlights, multiplier cone. The polished parabolically shaped multipliercone improves the efficiency of the fixture while maintaining reasonable glarecontrol. These lamps can be retrofit with HID or compact fluorescent hardwiredversions, with the proper retrofit being very application-dependent. If the cone isblack or dark bronze specular aluminum, the fixture was probably selected for aspecial application that should be identified.

x R and PAR lamp adjustable accent lights. Designed to look like fixed downlights, theseare adjustable accent lights in which the lamp’s pitch and rotation can be changed toproject a beam onto a specific item. In addition to using some of the common 120VPAR and R lamps, adjustable accent lights are often equipped with low-voltagelamps, such as the PAR-36, PAR-56, or MR-16. When a low-voltage lamp is used,the transformer is usually on the fixture chassis. In general, these are relatively poorretrofit opportunities, with few if any suitable compact fluorescent conversions.However, there may be specific instances where changing the inherent technology


4-9

might be appropriate, such as retrofitting a high-wattage incandescent with an HIDlamp. These situations will be very application-dependent.

x Open “A” lamp downlights. “A” lamp downlights are almost always used for generalillumination. Although the reflecting surface behind them is generally polishedalzak (aluminum), some inexpensive variations use white paint. There is no lensbelow the lamps. The trim may be a multiplier cone extension of the reflector or ashort black baffle. Open A luminaires are particularly well-suited to compactfluorescent conversions.

x Ellipsoidal downlights. Ellipsoidal downlights operate using the principle of anelliptical reflector; the light generated by the lamp is refocused and the beams oflight cross at a point out in front of the luminaire. In this way, all the light isrefocused through a small aperture and into the space. Ellipsoidal luminaires areeasily recognized, because they have a large-diameter reflector above the lamp but arelatively small hole in the ceiling. The trim may be either a black baffle or amultiplier (polished) cone. Because of the manner in which the elliptical opticalsystem works, the ellipsoidals do not lend themselves to compact fluorescentretrofits. Higher powered A-lamp ellipsoidals may be converted to HID, but quartzlamp ellipsoidals have no straightforward conversions. In general, if a retrofit issuitable (and usually it is not), it will be necessary to remove the entire ellipsoidalreflector and convert the luminaire completely to open compact fluorescent or HID.

x Lens Downlights. For general interior illumination, lens downlights were morepopular in the 50s and 60s, giving way to the open downlight in the 70s and later.However, lens downlights are still used in new construction, especially in wetspaces and outdoors. (Note: All metal halide downlights require a lens due to the potentialfor explosive lamp failure.) Because in most cases the optical properties of theluminaire are determined largely by the lens, which may either be prismatic,fresnel, or diffuser, most lens downlights use A lamps. Although lens downlightsusually lend themselves well to direct compact fluorescent or HID conversions, itmay also be possible to update the appearance of the luminaire by installing an allnew open compact fluorescent or HID kit. Because open luminaires are generallymore efficient than lens luminaires, additional energy savings can often be realizedwith this type of conversion.

x Low-voltage fixed downlights. The use of MR-16s and other low-voltage lamps in fixeddownlights is rare but occasional. Situations where these lamps are used are almostexclusively “high-end” office buildings and special applications like auditoria.Retrofit opportunities exist, but are usually not very attractive.

x Compact fluorescent downlights—horizontal burning lamps. Downlights with twohorizontal burning compact fluorescent lamps became popular in the 1980s. Becauseof the efficacy of the fluorescent source, retrofit opportunities are very limited.


4-10

Related Architectural Luminaires.

x Eyelid wallwashers. Eyelid wallwashers are generally found with many differenttypes of lamps, including A lamps, R lamps, and even MR-16 lamps. They havelimited retrofit opportunities, largely because the compact fluorescent lampsgenerally lack sufficient lumens to do adequate wall washing. An HID retrofit maybe sensible in situations having long burning hours.

x Recessed spread-lens wallwashers. These are high-quality luminaires and require high-quality retrofits to achieve decent performance. Luminaires using 300-watt R40 andhigh-wattage PAR lamps (typically Q250/PAR-38) might be retrofitted with 70-wattmetal halide PAR lamps to achieve relatively similar performance, but the retrofitwill involve the installation of the metal halide ballast, new socket, and high-impulse voltage wiring. As an alternative, some of these fixtures might be re-equipped with compact fluorescent assemblies designed for a similar opticalsystem; these are very product-specific and would require a minimum of two 26-watt lamps to achieve similar performance.

x Downlight wallwashers. These fixtures have similar retrofit problems to the eyelidwallwasher. Most compact fluorescent sources have inadequate lumen output; HIDretrofits would only be appropriate in spaces having long hours of operation withinfrequent switching and no dimming.

x Eyeballs. Eyeball luminaires are not particularly attractive, but often used as a crossbetween a wallwasher and an accent light. Depending upon the light source, aretrofit might be attempted; however, the proper retrofit will be very application-dependent.

Ratings and Listings. In the 1978 National Electrical Code, the first new requirementswere introduced to make thermal protection mandatory in residential downlights.Called type “T” (thermally protected), most manufacturers included this feature in allproducts, even though the Code did not require it for commercial suspended ceilings.

Subsequently, the Code also introduced requirements for “IP” (insulation protected)and “IC” (insulated ceiling) downlights for, again, primarily residential construction.The type “IP” is now required to prevent inappropriate applications of standardluminaires into direct contact with insulation. The type “IC” is required for situationswhere direct contact with insulation is necessary, especially in energy-efficientresidential construction. However, most fixtures in commercial applications eitherpredate the standards, or are type “S” (suspended ceiling—commercial only) or type“T.”

The thermal protector is usually inside the can near the socket. It is wired in series withthe lamp and opens if overheated. The insulation detector, usually a thick black rodabout 3” long, is often mounted to the junction box. It is actually a heating coil andcontact, with the heater always energized. The contact is in series with the lamp. If


4-11

insulation is packed around the detector, the contact mechanism will overheat anddisconnect the lamp.

Damp and Wet Labels. UL and other testing laboratories list downlights for indoor,damp locations (which are sheltered from direct rain or spray but can be outdoors), wetlocations (indoors or out, direct spray), and a special label for use near baths and spas.The label is often a function of the trim. It is important to use the proper trim withappropriate listing relative to the application to meet code.

Retrofits and Code. Since most retrofits replace a very hot incandescent lamp with acooler-operating and lower-wattage fluorescent or HID, there is little concern over thethermal properties of the downlight. Most retrofits will have only desirable impacts.

However, it is important to consider all aspects of the code when retrofitting. Mostretrofit kits are UL listed for general purpose applications and are damp labeled. Thereare no known wet labeled compact fluorescent retrofits; so be especially aware ofpotential code problems in outdoor luminaires and indoor wet areas like showerrooms.


Many—if not most—incandescent downlights can be retrofitted with compactfluorescent or HID lamps. In fact, retrofits of downlights are extremely common andthe most visible retrofits to be found. Replacing 3-4 watts of incandescent with 1 wattof fluorescent is a good rule of thumb; the challenge is to make the result aestheticallyacceptable.

Among the many options:

1. Medium-based screw-in compact fluorescent lamps are still the least costly way toconvert a simple downlight. The latest modular adapters, in which the compactfluorescent lamp is a replaceable quad or triple tube pin-based lamp, also means theretrofit will have good life-cycle economics, too. In most cases, the adapter includesa reflector optimized for the compact fluorescent lamp. These adapters are bestsuited for downlights in low ceilings (10’ high or less) since they are limited in watts(18-26 maximum) and beamspread (usually 60-80q or more). Most adapters aresuitably listed for dry or damp locations.

2. There are quite a few conversion kits in which a ballast and compact fluorescentsocket are installed in place of the existing incandescent socket. These kits eitherconvert the existing downlight reflector to a true compact fluorescent downlight, orreplace the reflector completely with one optimized for a compact fluorescent.Because these options are more optically precise, higher wattages (32-42 watts) andnarrow beams (30-40q) permit use in higher ceilings. Most kits are listed for suitabledry and damp locations, and some might also be suitable for wet location fixtures.


4-12

3. Likewise, some high wattage incandescent downlights can be retrofitted with asuitable metal halide lamp by adding a ballast, new socket and some new wiring.However, these conversions are uncommon and a listed kit of parts may not beavailable.

4. Outdoor applications for compact fluorescent conversions, once thought to belimited, have been increased by the advent of the low temperature electronic ballast.

5. Introduced in 1996, electronic ballasts that can be dimmed using ordinaryincandescent phase angle dimming (two wire standard circuit) permit compactfluorescent retrofits in situations where an incandescent retrofit might previouslyhave been avoided due to the need to dim. Keep in mind that compact fluorescents donot dim as low and that lamp color may shift differently than incandescent at low lightsettings.

Fluorescent (non-troffers)

Other than troffers, most fluorescent luminaires used in a wide variety of buildingtypes fall into the general categories of “commercial” or “industrial” lighting. Thesecategories cover everything from strip lights to shop lights, including many commontypes and quite a few special purpose luminaires. Like troffers, most industrial andcommercial fluorescents offer energy-efficient retrofit opportunities ranging from fairto excellent depending on the utility rate and the hours of operations.

General Information

Strip Lights. Strip lights or “channels” are the most basic of fluorescent luminaires, buthave a surprising number of uses. Like bare incandescent lamps, a strip light can beused to produce cheap general illumination, as long as efficiency and glare control arenot important. But often, the strip light is used in unique situations, such as insidecabinets or cases, in coves or valances, behind Plexiglas sign panels, or otherapplications where a “line of light” is needed.

Commercial Wraparounds. Wraparounds are relatively low-cost fluorescents designedto have a finished appearance whether surface-mounted or suspended by pendants.The luminaire is essentially a strip light with a U-shaped diffuser or lens surroundingthe lamp on three sides, producing some uplight as well as widely distributeddownlight. One- and two-lamp “wraps” are used in corridors, stairs, and a widevariety of general lighting and utility applications. Four-lamp wraps are often used forthe office and retail lighting, as well as some types of “clean” industrial lighting.

Supermarket Trough Luminaires. While markets use strip lights, industrials, or troffers,many designs prefer shallow “trough” luminaires. In retail lighting, an exposed lampis important both for economy and to convey to the customer that the store is “open.”The trough provides an improvement in the store appearance and visual comfort


4-13

without losing either of these important benefits. Moreover, the trough is an efficientlighting system, almost as high as an industrial system and far more efficient thanlensed or louvered recessed lighting.

Task Lighting. Ranging from bare strips to sophisticated luminaires with speciallenses, task lights are employed in homes, offices, hospitals, shops, and most otherbuilding types. The most common installation is underneath overhead cabinets in officeworkstations and over vanity and counter tops in labs, kitchens, exam rooms, andmany other types of facilities.


Lamps and Ballasts. The primary retrofit for fluorescent luminaires in these categoriesis to replace standard ballasts with electronic, and often, convert T-12 lamp systems toT-8. Unlike troffer lighting, many of these luminaires were originally equipped with 8’lamps and with slimline or high output (HO) T-12 lamps operating from standardmagnetic ballasts. It is also important to note that 8’ T-12 systems can be favorablyretrofitted with electronic ballasts (and for maximum light, RE8xx lamps) withoutneeding to employ T-8 lamps. For most situations either standard FO32 (F32T8) lampsor 8’ T-8 lamps (standard or high output) can be suitable retrofits. In the simplest ofretrofits, it is desirable to replace the existing maintained lamp lumens with an equalamount.

Reflectors and Delamping. Both specular imaging and high reflectivity white reflectorscan be used to improve lighting systems’ performance, usually permitting delampingor technology changes with fewer lamp lumens. However, few industrial andcommercial fluorescent luminaires other than troffers can benefit from this. Thefollowing chart shows some luminaire types, approximate efficiencies, andapproximate efficiency and coefficient of utilization (CU) gains.

Open fluorescent fixtures are already so efficient that there is little opportunity toincrease illumination much; to gain a meaningful increase will require specularreflectors that may create objectionable discomfort glare. Shielded fluorescentluminaires—such as wraparounds and washdowns—would suffer drastic changes inlight distribution if reflectors were used. Sometimes the best retrofit might be adifferent luminaire type, such as an open industrial.

Strip Lights. In addition to basic technology changes, consider the following retrofitsfor strip lights:

x General lighting. Adding a symmetrical reflector can increase the coefficient ofutilization (CU) of strip light systems, especially when the strips are suspendedfrom a ceiling or if the ceiling has poor reflectance. The reflector can be white,specular, or for a “design” appearance, white perforated to allow a little uplight (see


4-14

the discussion of small-percentage uplight under industrial fluorescent systems).Maintaining equal task illumination can occur with much lower power, hencegreater savings.

x Cove lights and valances. Add an asymmetric reflector to cove lights to increaseapplication efficiency and make lower watts possible. On occasion, these lights mayeven permit delamping.

x Under and inside cabinet lighting. Check lighting levels—many under-cabinet lightsproduce too much illumination.

Commercial Wraparounds. Because of the wide variety of uses for wraps, theretrofitter begins with many options, some of which may be applicable to the particularsituation. Some of these include:

x The tendency to use wraparounds in lower-cost construction also means that thelighting levels produced may not have been “designed,” and could be unnecessarilyhigh, allowing delamping or removal of luminaires.

x Older lenses may be depreciated, and replacing them can either significantly raiselight levels or allow for delamping or other energy savings in addition totechnology replacement.

x Removing the lens and replacing it with a formed reflecting surface, whilecompletely changing the character of the lighting, may be a very suitable retrofitallowing for delamping up to 2:1 due to significant increase in luminaires CU.

x Specular reflectors can be installed behind existing or new lenses to allowdelamping as well, although the delamping may be limited to going from four-lamps to three-lamps or from three-lamps to two-lamps.

Supermarket Trough Luminaires. While technology changes are certainly appropriateretrofits, specular reflecting surfaces can be used to increase CU but may introduce anappearance that worsens visual comfort and decreases the “open for business” effect ofthe bare lamp in the trough. Retrofitters are encouraged to carefully assess whether areflecting treatment might be acceptable. A better opportunity might be found in storesoverlighted by current IES or industry standards.

Task Lighting. Better quality task lights employ optical controls and dimmers tomanage lighting levels on the counter below, but most task lights use basic lamp andballast technology. The result is overlighting of the counter below—an obvious energy-saving opportunity.


4-15

Table 4-3Fluorescent Replacements

Existing Condition Equal Lumen Replacement (approx.)

F40CW/magnetic ballast (Std or EE) (40-watt T-12 RS lamps; also for F48T1240-watt slimline lamps*)

FO32/8xx, elec/hybrid ballast BF=.95FO32/7xx,elec/hybrid ballast BF=1.00

F40CW/ES, magnetic ballast (34-watt T-12 lamps) FO32/8xx, elec/hybrid ballast BF=.75FO32/7xx, elec/hybrid ballast BF=.80

F96T12/CW (slimline), magnetic ballast (75-watt 96” lamps) FO96/8xx, electronic ballast BF=.95FO96/7xx, electronic ballast BF=1.00(2)FO32/8xx, elec/hybrid ballast BF=.95(2)FO32/7xx, elec/hybrid ballast BF=1.00

F96T12/CW/ES (slimline), magnetic ballast (60-watt 96” lamps) FO96/8xx, electronic ballast BF=.80FO96/7xx, electronic ballast BF=.85(2)FO32/8xx, elec/hybrid ballast BF=.80(2)FO32/7xx, elec/hybrid ballast BF=.85

F96T12/CW/HO/ES, magnetic ballast (85-watt 96” HO lamps)* (2)FO32/8xx, electronic ballast BF=1.20FO96/HO/8xx or 7xx, electronic ballast BF=.85

F30T12CW, magnetic ballast (30-watt 36” lamps) FO25/8xx or 7xx, electronic ballast BFt.90

F30T12/CW/ES, magnetic ballast (25-watt 36” lamps) FO25/8xx or 7xx, electronic ballast BFt.80

F20T12CW, magnetic ballast (20-watt 24” lamps) FO17/8xx or 7xx, electronic ballast BFt.80

Abbreviations: 8xx means rare-earth phosphor, any color temperature, 80 + CRI; 7xx means rare-earth phosphor, any colortemperature, 70 + CRI; elec/hybrid means an electronic OR hybrid ballast.

Note that high-output standard lamps (e.g. F96T12/HO/CW) do NOT have an equal lumen replacement, although in most applications,retrofits suitable of energy-saving HO lamps may be appropriate. For other existing lamps and/or replacements, make certain to equatethe product of the retrofit lamp and retrofit ballast factor with the existing or designed condition.

* Lamps annotated with an asterisk may require retrofitting with low-temperature-starting ballasts when used outdoors or in coldenvironments.

Table 4-4Reflectors and Delamping

Type of Luminaire Standard Efficiency Efficiency with BestReflector Upgrade

CU at RCR 2.5, 50/30/20Reflectances

CU with Best EfficiencyUpgrade

Strip Light 92% 92% 65% 70%

Industrial 90% 92% 68% 74%

Wraparound 68% 74% 48% 54%

Supermarket Trough 88% 91% 68% 72%

Washdown / Vaportight 66% 72% 50% 54%

Recessed Troffer 68% 76% 55% 64%


4-16

Table 4-5Fluorescent Task Light Retrofit Opportunities

Lamp and Ballast Type Retrofit Opportunity

F8T5, F13T5 Probably none**

F13T8, F14T8, F15T8, F30 T8 Probably none**

F14T12, F15T12 Probably none**

CF9T, CF13T Electronic ballast with low BF

F20T12 F17T8/electronic ballast with low BF, tunable or dimmable ballast, or two-level ballast.




F72T12 2-F25T8 OR 3-F17T8/electronic ballast with low BF, tunable or dimmable ballast, or two-levelballast.

**Electronic ballasts may be available for some of these. In addition, the appearance of some lamps can be improved through the useof rare earth phosphor lamps. Some applications may also be suitable for retrofitting with the latest T2, T3, and T4 technology. But dueto low unit wattage, retrofits probably will not experience suitable payback.

In each case a major part of the savings are achieved by using the lower lighting levelscreated by the ballast options. For instance, an F40T12 task light uses a one-lamp T-12rapid start or even preheat ballast, and consumes as much as 50 watts.

HID Lighting Systems

Commercial HID lighting systems are used in a number of facility types, includingoffices, schools, stores, airports, and shopping malls.

General Information

Troffers. HID troffers are very similar in appearance to fluorescent troffers and aremade in two basic types:

x prismatic lens troffers, found in a wide variety of applications, including indoorsports courts, natatoria (indoor pools), grocery stores, and other spaces with highacoustic tile ceilings. In spaces like natatoria with atmosphere considerations (e.g.water or moisture) the lens may be gasketed to help keep the luminaire clean andprevent interior materials from rusting. Heavy-duty lenses are available for gymsand game courts.

x parabolic troffers, found in upscale spaces with high acoustical ceilings such asairport terminals, specialty stores, shopping malls, and atria. Most of theseluminaires are for metal halide lamps and incorporate a clear lens above theparabolic louvers.


4-17

Most HID troffers are 2’x 2’ fixtures employing 250- or 400-watt lamps, usually eithermercury vapor or metal halide.

Downlights and Wallwashers. Many of the architectural downlights for incandescentand halogen lamps (see prior sections) have HID versions, including open parabolic,ellipsoidal, R or PAR lamps with cones and baffles, adjustable PAR lamp, downlight-wallwashers, and various spread-lens wallwashers. These luminaires are used for bothinterior and exterior locations, such as overhangs and canopies, because of the low-temperature behavior of HID lamps. For indoor applications, most of these luminaireswill be metal halide or mercury vapor. The poor color of HPS makes them undesirableindoors, and they will more often be found in exterior applications.

Track Lights. HID track lights are uncommon. Generally, the size of the ballast hasprevented HID track lights from being developed. Other than odd and custom fixtures,only a few track fixtures exist using HID lamps. Systems most likely to be foundinclude compact white sodium luminaires and HQI metal halide luminaires.

Indirect Lighting Systems. As ceiling height increases in office buildings and otherspaces having flat reflective ceilings, uplighting becomes an appealing way ofproviding ambient light. HID lamps can be especially cost-effective for this application,as they can illuminate a larger area per dollar than fluorescent. While the classicaldrawbacks of HID remain (limited switching, color shift, etc.), these systems have beenused for many years and their popularity remains high in some new designs. Metalhalide systems are most common and HPS systems, while uncommon, have beendeveloped. Most indirect systems, to make sense and minimize problems, use high-wattage lamps.

Some of the most likely lighting systems one might encounter:

x suspended “puck” systems, a classic design with a reflecting system built around avertical lamp enclosed by a cylinder resembling an oversized hockey puck to theviewer. Puck systems are usually 400–1000 watts and are used in a variety of spacesranging from classrooms to libraries, airport terminals, and indoor tennis courts.Most puck systems are metal halide. There are some double-puck systems withmetal halide and high-pressure sodium in each of the pucks, designed to overlaptheir light and create efficiently-generated warm-toned illumination.

x suspended or panel-mounted “box” systems, usually with horizontal lamps andreflectors, up to about 400 watts. There are both round and square boxes. Someround luminaires were mounted atop cylinders on the floor, earning the nickname“water heater.”


4-18


This section presents retrofit opportunities specific to HID fixture types. See alsoChapter 3 for information on generic HID retrofit opportunities.

Troffers.

1. Convert 400-watt mercury vapor fixtures to 325-watt metal halide lamps andballasts. This is one of the top retrofits because, in addition to significant energysavings, lighting levels and color will improve dramatically.

2. Investigate converting 175–250-watt luminaires to new fixtures with three T-5 twintube fluorescent lamps and electronic ballasts. Generally, three F40T5 lamps willproduce the same maintained light level as a 175-watt metal halide with savings ofabout 60–70 watts; three F50T5 or F55T5 lamps will produce the same maintainedlevels as 250-watt metal halide with savings of around 100 watts. This worksbecause of the poor lumen maintenance of the metal halide relative to thefluorescent. An added benefit is that the fluorescent can be switched frequently. Theimproved color of the fluorescent and elimination of flicker will be welcome.

3. Investigate converting 400-watt metal halide luminaires to new fixtures having 6 to8 F40T5 or F50-55T5 lamps. Keep in mind the appearance of the fluorescentluminaire in this case might not be acceptable.

4. Consider any of the other HID options, such as new lamp/ballast systems,high/low ballasts, and low wattage lamps.

Downlights and Wallwashers.

1. Interior applications in lower-ceiling spaces would generally use low-wattagelamps. Look into compact fluorescent retrofits which reduce wattage, improve color,and allow more frequent switching. For instance, replace a 100-watt mercury vaporlamp or a 70-watt metal halide with a 32- or 40-watt compact fluorescent (electronicballast). The existing cone and trim may also need changing to match the optics ofthe compact fluorescent or perhaps to remove a lens. Look into conversion kits fromthe original manufacturer.

2. Replace higher-wattage mercury vapor lamps with metal halide, such as in spread-lens wallwashers where a 175-watt mercury vapor R or PAR lamp can be replacedwith a 100-watt metal halide with new ballast and socket. This approximate wattageratio is generally true for any wattage mercury to metal halide conversion.Remember when converting to metal halide to use self-protected (shrouded arc-tube) lamps, and to investigate state-of-the-art lamp/ballast combinations.

Track Lights. Low-wattage HID lighting systems can be expensive to retrofit andrarely will be cost-effective. Consider the following, however.

x Compact white sodium luminaires, generally with electronic ballasts and in therange from 35-watt PAR lamps to 100-watt T-lamps, might be replaced with newtechnology metal halides. The metal halide lamp would use about 60% of the


4-19

power for the same approximate lumen output. However, related changes in lightspectrum may be undesirable; so be certain to proceed cautiously with this type ofretrofit. If the system is not being used for highlighting but rather for wallwashingor floodlighting, consider a fluorescent track luminaire.

x Compact HQI metal halide luminaires, also generally with electronic ballast (70watt) are already very efficient and no cost-effective retrofit opportunities exist.

Indirect Lighting Systems. Because most of these systems are higher-wattage metalhalide (and/or HPS), retrofit opportunities are limited. Refer to the general retrofits forHID lamps in Chapter 3. Many of these rooms are high-ceiling spaces, and therefore,retrofits will be difficult and perhaps, too expensive. For spaces with lower ceilings, itis possible that the system is improperly designed and an all new fluorescent systemmay be an appropriate response, using less energy and providing better light.

There are a few low-wattage HID systems, most of them utilizing expensive luminairesthat effectively prevent any type of retrofit. Note that spaces using this type of lightingmay be candidates for a new lighting system, as the owning and operating problems oflow-wattage HID indirect systems would probably be apparent.

Commercial Decorative Lighting

General Information

Decorative lighting fixtures are typically used in hotels, restaurants, retail stores, andother building types where their style is important as an ornament in the architecturalor interior design. In addition, decorative lighting is used in office building entriesand lobbies, meeting and board rooms, and other common space. Traditional andhistoric buildings are often completely lighted by decorative lighting fixtures.

Decorative lighting types include chandeliers, pendants, sconces, table lamps, floorlamps, and other fixtures whose enclosure is generally ornamental or designed to bepart of an architectural theme. Following are some of the most commonly encounteredfixture types.

Ceiling and Close-to-Ceiling Fixtures. Decorative ceiling and close-to-ceiling fixturesare used in hotels and many other commercial situations. Some of these fixtures arefluorescent, using ordinary straight tubes, U-bent tubes or Circlines. The vast majority,however, are incandescent. In all applications the usual intent is to provide lots ofgeneral light.

Chandeliers. Chandeliers were first invented to hold candles and have evolved into awide variety of electrically-illuminated luminaires that are suspended from the ceiling.


4-20

Chandeliers differ from pendants (see below) in that chandeliers are ornate and usuallytraditional in style.

Traditional designs of chandeliers generally result in exposed lamps (in keeping withthe exposed candles of their heritage). Many small incandescent lamps, typically clear,are consistent with the style. These lamps can utilize medium, intermediate,candelabra or mini-candelabra sockets, with smaller sockets being quite common tohouse the lower-wattage lamps appearing as candles. More contemporary chandeliersand the very large fixtures used in civic and historic buildings may have lampsconcealed behind ornamental glass or metals. While occasionally these fixtures mayactually use fluorescent or HID lamps, they typically use several ordinary incandescentlamps on medium sockets.

Pendants. Pendants are suspended luminaires that are usually smaller and lessornamental than chandeliers. Whether a luminaire is a “pendant” or “chandelier” issometimes a matter of interpretation or taste.

Most pendants, like chandeliers, use one or more incandescent lamps. However, thereare a number of modern designs of pendant luminaires using HID or compactfluorescent lamps specifically for illuminating larger spaces like offices.

Sconces. Sconces are wall-mounted luminaires that, like chandeliers, tend to beornamental. Sconces range in style from traditional candle-like designs to extremelymodern luminaires. Light distribution also varies from simple diffuse light tosophisticated, asymmetric uplights.

Sconces have been particularly appealing since the early 1980s, experiencing arenaissance of interest among architects and designers while concurrently providing anopportunity to use compact fluorescent lamps for illumination in many different spacetypes. Although it is uncommon to find a traditional sconce with a compact fluorescentlamp, most new sconce designs offer incandescent or compact fluorescent options.

Table Lamps. There are many designs for table lamps. Some might be called “tasklights;” they are modern in style and designed to be moved into position near the task.Task lights are commonly used as supplemental lighting in offices, usually as a stop-gap measure because the built-in lighting is inadequate at that particular location. Therelatively high cost of an attractive task light limits use of the best products toexecutives, but modest luminaires like the classic “architect” lamp are used in manysituations.

More traditional table lamps have been limited to residences, hotels, and executivesuites, mostly to play to the residential aesthetic. However, the plain table lamp with


4-21

an appropriate light source (fluorescent) and properly shaped shade may be anexcellent task light for many situations, including computer-intensive offices.

Floor Lamps and Torchiers. While the traditional floor lamp is as varied the as thetable lamp, “torchier” is the name given to contemporary floor luminaires. Manytorchiers have an uplight distribution, usually equipped with a relatively high-wattagehalogen lamp. A few designs have been recently introduced using compact fluorescentlamps.

Marquee Lights. Marquee or string lights are used for a variety of interior and exteriorlighting accents at theaters, hotels, restaurants, casinos, and other entertainmentfacilities. Typical marquee lamps are medium, intermediate or candelabra based lampsbetween 10 and 60 watts, usually in a G (globe) or S (sign) bulb. Often marquee lampsare controlled by dimmers or electromechanical switches.


Decorative luminaires present a challenge to the retrofitter that he or she does notnormally encounter. The primary objective requires an equal balance of aesthetics andenergy efficiency. To achieve efficiency without retaining (or improving upon) theappearance and quality of the space will usually be unacceptable.

If Dimming Is Important. Many chandeliers and sconces, especially in hotel meetingrooms and conference facilities, operate from an incandescent dimming system andoften for good reason. If dimming is present and used, consider one of the followingpossibilities.

x Reduce lamp wattage. Many installations rely upon dimming and never operatelamps at 100% power. By changing the use of the dimming, socket watts can bereduced considerably. For instance, a 100-watt lamp typically operated at 75 wattsproduces about the same light as a 60-watt incandescent lamp at full brightness.While relamping costs will increase, energy consumption will decrease. Keepingthe right lamp in the socket is, of course, the biggest problem: Try using stickersnoting the correct wattage.

x Use halogen lamps of lower wattage. For installations run at full light periodically, trylower-wattage halogen lamps, such as a 75–90-watt replacement for a 100-wattincandescent lamp. Note that if “long-life” lamps have been used in the past, alower-wattage halogen lamp can be used because long-life incandescents are lessefficient than standard incandescent.

x Consider converting small incandescent lamps to low-voltage halogen. A tricky job, but a5-watt halogen 12-volt lamp can generate as much light as a 10-watt incandescent.


4-22

x Reduce the amount of light generated from the dimmable source. Especially if othersources of light are available and/or the light levels are high, this will permit thedirect use of incandescent lamps of lower wattage.

It may also be possible to retrofit the lighting with a dimmable compact fluorescent.Dimming ballasts for compact fluorescent lights are available, but most require adimming device and control signal that prevents use of the existing incandescentwiring. Recent developments in fluorescent dimming, however, have included a fewdimming ballasts that can respond to the signals of an ordinary incandescent dimmer.The compatibility of the ballast and dimmer will be critical in considering this type ofretrofit. Changing the dimmer may not be easy: it may involve rewiring and may noteven be possible with the dimming system.

If Dimming Is Not Important.

1. Convert fluorescent luminaires to T-8 lamps and electronic ballasts. This retrofit isstraightforward and almost always desirable. Note that because many of theapplications of decorative fluorescent fixtures are overlit, consider using low ballastfactor electronic ballasts.

2. Reduce socket watts. There are many ways to do this.

x Simply settle for less light. Reducing lamp wattage is easy and cheap. However,this method is unlikely to persist, since the user’s could revert to the old set-up.

x Make a lamp type change. For marquees and other applications using exposed Glamps, retrofit products using several low-wattage lamps inside a G lamp bulbwill create an acceptable new effect. Typical replacement uses a 7-watt screw-indevice (with 7 small 1-watt lamps) to replace a 25–40-watt regular incandescentG-25 or G-40 lamp. The lighting level will diminish but the sparkle will actuallyincrease.

3. Screw in a compact fluorescent. The evolution of compact fluorescent screw-in lampspermits many incandescent lamps to be directly replaced, especially in luminairesthat use a shade or shield. Keeping in mind the (approximate) 4:1 relationshipbetween incandescent and fluorescent watts, the higher-wattage compactfluorescent lamps will prove to be more desirable to equal the light output of a 100+watt incandescent lamp.

Table and floor lamps may require changing either the harp, the shade, or oftenboth. Consider using screw-in adapters where the ballast and socket are semi-permanently installed to prevent theft and snap-back. Lamps with three-waysockets can be equipped with one of several types of three-way CFL products on themarket.


4-23

Other decorative luminaires often allow direct replacement of incandescent lampswith self-ballasted screw-in compact fluorescents. To prevent snap-back, semi-permanent ballast/socket kits are recommended, as are hard-wired conversions (seebelow). However, the low cost of ordinary medium-based CFL’s may besufficiently attractive to make the snap-back and theft risks worth taking.

4. Make a hard-wired conversion to compact fluorescent. This is the preferable way to makea retrofit that persists and has low theft value. Most conversions are not easy andthere is often no room for the ballasts. However, the recent introduction of compactelectronic ballast packages makes these conversions even easier. Inline ballasts mayalso be used for permanent conversions of table and floor lamps, keeping in mindthat the preferred lamps may require four wires and therefore, rewiring of theluminaire.

Special Considerations for Wall Sconces. In 1992 the Americans with Disabilities Act(ADA) became Federal law. Among its many requirements is the prohibition of wallsconces that project more than 4” from the wall when mounted 80” or less abovefinished floor in a hallway or path of egress. Most incandescent decorative sconces failto meet the law. Rather than retrofit, many building owners choose to replace non-complying incandescent sconces with complying fluorescent sconces. New productsare available in every design style and cost.

Commercial Utility Lighting

General Information

In addition to the mainstream lighting systems of commercial facilities, there are a widevariety of special-purpose and utility lights using many different light sources. Often,there are just a few of these compared to the quantity of regular lighting systems.Retrofitting them is generally advisable, both to save energy and to permit moreconsistent maintenance.

Strip Lights. Fluorescent strips are used in a variety of applications, from valence andcove lights to closet lights, task lights, and many other utility applications.

Case Lights. Used inside of cases for everything from food to jewelry, case lightsconsume a surprising amount of energy. Incandescent case lights include showcase-lamp and low voltage styles. Fluorescent case lights use a variety of straightfluorescent types, ranging from very short T-5 preheat lamps to 8’ slimline and HO caselights for food and other large displays.

In assessing case lights, it is important to note that around food, protective covering isrequired. Sleeves that slip over lamps or lamps with integral plastic sleeve protection


4-24

are commonly used. Bare and unprotected fluorescent and incandescent lamps aregenerally not permitted around food, the only exception being the thick hard glass-protected PAR lamps. Lamps inside of refrigerated cases may also require sleeves tomaintain temperature and therefore, light output.

Vanity Lights. Lights specifically designed for vanity lighting are used for these andother applications. Generally, a vanity light is designed to be mounted over or beside amirror. Incandescent vanity lights are used in homes, hotels, and many othercommercial and industrial applications; fluorescent vanity lights are less common andare usually found in modest facilities.

The appearance of the vanity light may be important. In other cases, durability mayoutweigh other considerations.

Step Lights. Interior and exterior step lights are used for stairs, walkways, and similarsituations where a low wall-mounted light is needed. Incandescent, fluorescent, andHID versions can be found. In particular, HID versions tend to be for exteriorapplications but may be used indoors in commercial space.

Step lights tend to be the least efficient way to illuminate a path; so in assessing steplight installations it is important to confirm that step lights are the only good solution.Sometimes the opportunity exists to remove and replace them with more efficienthorizontal surface illumination such as downlighting.


The wide variety of utility lights makes specific retrofits hard to recommend. Thefollowing general considerations can be followed, and the retrofit designer shouldevaluate each case independently to assure the best choice.

1. Always consider replacing incandescent fixtures with new fluorescent luminairesdesigned to do the same job. This is especially true for vanity lights, display caselights, and other luminaires where a technology retrofit would not be possible ormight entail considerable luminaire reconstruction.

2. For step lights and other sources that conceal the lamp, investigate incandescent-to-fluorescent or even HID-to-fluorescent conversions. Screw-in CFLs are areasonable idea here as the lamps are not easily accessed except by trainedpersonnel. In replacing a low-wattage HID with fluorescent, it is possible toremove the HID ballast and replace it with a compact fluorescent ballast; of thesame input voltage. Incandescent luminaires probably do not have the space for aballast so a screw-in CFL may be preferred.

3. Of course, be concerned if the luminaire is being dimmed. (Dimmingconsiderations and options are discussed under decorative lighting.)


4-25

4. For luminaires already using fluorescent lighting, it is probably best to apply recenttechnology, such as T-8 lamps. Note that in refrigerated cases, low-temperatureballasts and tube-warming jackets will be needed. In many other situations, use oflow-ballast factor electronic ballasts will result in acceptable lighting levels but savethe maximum amount of energy.

Exit Signs and Other Self-Illuminated Signs

General Information

Self-illuminated exit signs are required by fire code in commercial buildings and inmultiple-residential buildings like condominiums, hotels, and motels. Some self-illuminated directional and advertising signs are very similar in construction.

Because exit signs are regulated by fire codes and their appearance and brightness fallunder the jurisdiction of the fire marshal, take particular care when assessing exit signsfor possible retrofit. Following are some of the key options and considerations:

x Face color is important but surprisingly inconsistent. Some municipalities requirered letters; others require green. The surrounding field about the letters seems lessimportant; so one may find red letters with black, white, or other backgroundacceptable to the same fire marshal.

x Many exit lights have a lens in the bottom to provide downlight. The downlight isoften part of an overall emergency path lighting scheme and should be regarded ascritical unless other more specific emergency lighting is provided for this purpose.

x Whether an exit sign is single or two-sided may dramatically affect the retrofitapproach

x Many exits incorporate a battery backup, often with separate low-voltageincandescent lamps in the event of power failure.

x The vast majority of exit luminaires are incandescent, usually using two low-wattage, long-life incandescent lamps for normal power operation. Lamp life israted especially long; so assumptions about relamping when evaluating economicsof retrofitting should be guarded.

x The battery backup units employed in many exits may no longer work. Be certainto check while assessing the installation. Failure will probably be due to batteryfailure. If the battery system fails to work, this may encourage an all-new exit signrather than retrofitting and replacing the battery.


Exit signs in which the downlight must be maintained have two options:


4-26

1. Replace the incandescent lamps with compact fluorescent. Two 5- or 7-watt twintube lamps are quite suitable for replacing the two incandescent lamps usuallyfound with a net savings of around 15–18 watts per lamp. These conversions, whichare hardwired, are inexpensive and work fairly well. The primary disadvantage isthat lamp life of the compact fluorescent will probably be shorter than theincandescent it replaces.

2. Replace the luminaire with a new unit employing LED faces and LED downlight.First costs will be higher, but energy savings increase as well. One of theadvantages of this retrofit is that LED life is extremely long—much longer than longlife incandescent or fluorescent.

Exit signs not employing (or not needing) downlight enjoy other options:

1. Replace incandescent lamps with LED retrofits. There are a number of differenttypes of kits designed for this purpose. Be certain to use the right color.

2. Replace incandescent lamps with compact fluorescents. This retrofit saves energybut has drawbacks, including short lamp life.

3. Replace incandescent lamps with incandescent rope light or other types ofspecialized adapters. (These work by placing incandescent lamps in optically moreefficient locations and by distributing the light source.)

4. Replace exit signs with radioluminescent or other types of signs that generate lightwithout electricity. While these signs have the lowest light levels (and may notmeet fire marshal requirements), they also consume no energy.

It is especially important to obtain the input of the local fire marshal with respect to anyexit sign retrofit. Most retrofits change the amount of light and the character of thelighting and sign sufficiently that the retrofit—even if it is tested to comply with ULsafety requirements and listed—may not be acceptable to the authorities.

Track Lighting

General Information

Track lighting was invented in the late 1960s as a means of bringing some of theversatility and drama of theatrical lighting to architectural projects. It rapidly becamethe standard means for lighting retail stores, museums, galleries, and similar facilities.But it is also a popular means of solving lighting problems in a wide range of projectsranging from churches to restaurants.

Tracks made by different manufacturers are generally NOT interchangeable. A trackfixture or “head” made for one brand of track will not fit another brand. Track itself isone of several configurations:

x single 20A circuit (common lowcost track)


4-27

x two 20A circuit (most commercial and museum heavy-duty track)

x three or four 20A circuit (rare; heavy-duty grade)

x one, two, or more circuits greater than 20A (also rare, heavy-duty grade)

Most track is the lighter commercial grade. Heavy-duty tracks, which can be identifiedby the heavier-gauge aluminum track and beefier head connectors, are generally usedin museums and convention facilities where change is common and larger fixtures areused. Commercial grade track is used in stores and other situations where ordinaryheads are used and change is less frequent.

Almost all tracks are fed at 120 volts; but occasionally, tracks are energized at 12 volts.Standard track operated at 12 volts with specially wired heads has been known to haveconnection problems and fire potential; track systems designed specifically for low-voltage do not have this type of problem as the connections are better designed for thehigh currents needed for low-voltage lamp operation.

A monopoint is a track or track-like head mounted to a canopy cover or junction box.Track makers produce a canopy with a short piece of track allowing a single head to beinstalled. Sometimes the canopy has an integral transformer allowing a low-voltagehead to be mounted to it.

Standard track fixtures or “heads” include

x R or PAR lamp heads, by far the most common. They are used to accentuateartworks and displays.

x low-voltage PAR-36 and MR-16 lamp heads, used in a manner similar to the abovebut allowing the greater focus and precision of low voltage lighting. There are afew products with built-in reflector systems that use the tiny bi-pin halogen lampsinstead but perform in a similar manner.

x heads that turn “A” lamps and “SB” lamps into display spots or floods. Far lesscommon, these fixtures have built-in reflectors for the standard lamp.

x Wallwasher heads using A lamps, 100–250-watt halogen lamps, or fluorescentlamps.

x special display heads using high-wattage halogen PAR lamps

x special display heads using metal halide PAR, metal halide HQI, or white sodiumlamps


4-28


Before proceeding, it is a good idea to make sure the track system connections are tightand functioning. Any sign of arcing or burning on the track should be investigated andthe problem fixed.

Retail Display Lighting. Most retail display lighting requires drama and punch. Thiscannot be provided by fluorescent retrofits, particularly medium based screw-ins. Usehalogen or halogen infrared-reflecting lamps to reduce lamp watts but maintainessentially similar performance and appearance.

The best opportunity to retrofit retail display track is when fixtures are being used aswallwashers. Electronically ballasted fluorescent wallwashers using twintube lampsactually work better than incandescent or halogen wallwashers and at greatly reducedpower. Most track manufacturers now make one or more standard products that canbe simply “plugged in.”

Grocery Stores, Car Dealerships, and other Larger Displays. New metal halide andwhite sodium track heads can be used to replace incandescent and halogen heads whenilluminating larger areas such as produce gondolas, cars, and sporting goods.

Restaurants, Hotels, Houses of Worship, Theme Parks, and other Designed Spaces.Generally, track used in these facilities is being used to create a specific appearance. Itis often dimmed. Retrofits should be limited to halogen or halogen infrared-reflectinglamps with special attention to creating a similar effect.

Convention Facilities. Convention halls and many hotel ballrooms employ track toilluminate speakers, head tables, temporary displays, and other events. This isspecialized lighting that probably should not be part of a retrofit program.

Other Casual Uses of Track Lighting. There are many places where track has beenused for convenience. Using careful judgment, the retrofitter may find someincandescent track heads could use a self-ballasted CFL that would provide satisfactoryperformance.

Industrial

Industrial Fluorescent

General Information

Industrial luminaires are generally open strips with symmetric reflectors as part of thebody of the luminaire. Economy industrials are often called “shop lights” and are sold


4-29

at hardware stores as well as through normal electrical distributors. Better-qualityindustrial fluorescent luminaires have larger reflectors, in many cases with slotopenings in the top to permit a small percentage of uplight into the space. The mostexpensive industrials may have separate parabolically-shaped lamp compartments.

In addition to the basic luminaire, industrial luminaires may be equipped with a widevariety of options, many to protect the lamp from breaking and workers from brokenglass as a result. The most common include

x protective wire cage guards

x egg-crate louver, usually white flat bladed

x prismatic lens

The better-quality industrial luminaires may be finished in baked enamel paint orporcelain, particularly if the designer was concerned about longevity and resistance tocorrosion. Or the luminaire body might be aluminum rather than steel, again tominimize the negative effects of corrosion. Surface reflectivity can be assumed todepreciate and offers reasonable retrofit opportunity. However, the retrofitter shouldassess the atmosphere in the application to determine the requirements of theluminaire’s surface finish. For instance, white powder coat replacement reflectors maybe more suitable than specular reflecting materials due to the application’senvironment. In addition, lamp sockets are often different, using turret-type andspring-loaded sockets to better hold lamps and maintain contact pressure despitefrequent vibration.

If the lighting levels of an otherwise older and/or poorly maintained lighting systemare found to be adequate, then considerable opportunities to save energy includeoptical improvements such as replacement of (or repainting) reflecting surfaces;replacement or removal of lenses; replacement, repainting, or removal of louvers; andlowering lighting systems to improve the CU by reducing the room cavity ratio (RCR).Of course, these savings are added onto technology changes to modern lamp/ballastsystems.

But many older lighting systems no longer produce acceptable illumination due toinadequate maintenance. The retrofitter should determine whether this is the casebefore proceeding. Renewing the lighting system with a technology upgrade and new,clean reflecting and refracting materials might be the best service for the customer.


Industrial lighting applications may offer redesign opportunities that save energy witha minimum amount of change-out. For instance, changing from general illumination to


4-30

task-and-ambient solutions, combined with technology upgrades, may save the mostenergy and minimize cost by adding only task lighting where needed.

Most industrial fluorescent luminaires can be directly retrofitted with T-8 lamps andelectronic ballasts. Considering the many options—standard T-8, T-8 lamps with lowor high light level ballasts, high output T-8 systems—it should be possible to retrofit allbut VHO fluorescent systems directly.

In cases where slimline, HO, and VHO fluorescent are being used, it is important toascertain the design temperatures before considering a retrofit. HO and VHO systemstend to operate well at low starting and ambient temperatures. If the application isstrictly for general lighting, however, sometimes a retrofit employing mulitple F32T8lamps can be used. For example, a single lamp luminaire using anF96T12/HO/CW/ES lamp (8000 lumens) might be retrofitted with two F32T8 lampsand a two-lamp high-light-level ballast (7400 lumens). Or, a luminaire employing twoF96T12/HO/CW lamps (17,600 lumens) might be retrofitted with eight F32T8 lampswith low-light-level electronic ballasts (17556 lumens).

Watertight Fluorescent

General Information

Sealed and gasketed or “watertight” fluorescent luminaires are used in applicationswhere either the atmosphere surrounding the luminaire is expected to be constantlywet, or in those situations where extreme dirt build-up is intended to be removed byperiodic high-pressure washing using water with or without detergent.

Although there are many different styles, the most common is a rectangular fixture,typicallly 4 or 8 feet long and 8” to 12” wide. Most watertight fluorescent fixturesemploy a plastic or fiberglass chassis and use few or no exposed metal parts to furtherwithstand corrosion.

The lens is usually a single piece of injection-molded plastic that might be clear, diffuse,or employ a prismatic pattern. In most applications, the photometric distribution of theluminaire is not demanding. Observe closely how the existing ballast is mounted—ballast case heat dissipation is a problem with non-metallic fixture housings. Startingand operating temperatures may also be a concern, as often these fixtures are used inunheated spaces.

Retrofit Opportunites

The primary opportunity is converting the fluorescent lamps to T-8 type with electronicballasts. Make certain the starting temperature of the new ballast is correct. Secondary


4-31

opportunities might include the addition of a specular or white reflector to increase thedownward light component. This will change the luminaire’s performance; socarefully evaluate the photometric difference.

Also investigate the lens being used. Replacement of an aged lens or substitution of aclear or prismatic lens in place of a diffuser can increase fixture efficiency enough towarrant use of a lower ballast factor or perhaps even a lesser output lighting system.

HID High Bay Area and Aisle

General Information

So-called “high bay” fixtures are designed specifically for use in spaces with a need tomaintain a clear height of roughly 25 feet or more. Applications of high bay fixtures arenot limited to industrial spaces, for they are used in all types of high space, notablygymnasia and similar spaces, where utilitarian-appearing luminaires are acceptable.High bay fixtures generally are between 250 and 1000 watts. Different distributions ofcandlepower, including width of beamspread and special beam shapes as for aislesbetween equipment or storage racks are some of the major options. Aluminum, glassprism, and acrylic prism reflectors are used, with minor advantages to each. Uplightprovided by a gap between the socket and reflector or from the glass or acrylic reflectorhelps make this lighting more comfortable.

High bay systems may be installed in a number of ways. Some high bay lightingsystems are installed on a wireway system not unlike track lighting, permittingrelatively easy fixture removal, relocation, and replacement. In other installations,hook hangers and cord-and-plug installation permit rapid removal and replacment of afaulty unit. And of course, conventional hard-wiring installations are used in manybuildings. The wiring method may affect retrofit situations more than most otherlighting types, if for no other reason than the height of the luminaire.


High bay applications suggest the following primary considerations:

1. Convert mercury vapor luminaires to metal halide or HPS. The cost of convertingmay suggest a new luminaire instead of any kind of rewiring.

2. Examine the various lamp and ballast options in the section on HID lamps, such asthe metal halide linear reactor and hybrid systems, lower-wattage lamps and two-level systems (both MH and HPS). Also consider removing metal halide lenses andusing self-protecting lamps, especially where the lens is visibly dirty.

3. Examine the possibility of changing to a task-and-ambient lighting design in whichthe general lighting levels are made lower and supplemental task lighting, mostly


4-32

fluorescent, is used only where needed. It may be possible to reduce the generallighting system’s power considerably while achieving a net improvement in tasklighting.

4. Consider low-wattage metal halide lamps to retrofit existing metal halide fixtures.For instance, replace a 400-watt lamp with a 360-watt lamp without any noticablechange in light levels or performance. (Note lamp operating position limitations—usually not a problem in high bay lighting as lamps are usually vertical, base up).

Relatively new information on visibility and high-pressure sodium sources may affectthe lamp selection for high bay lighting. While there are no problems with HPSlighting for most industrial situations, metal halide is clearly advantageous inrendering small targets such as industrial assembly or fine machining. Also keep inmind the flicker of both metal halide and HPS lamps, and make certain lamps arerotated in phases to minimize stroboscopy. In some cases, it may be desirable toreplace existing HPS lamps with metal halide, for which there are a few specific metalhalide lamps designed to operate on HPS ballasts.

HID Low Bay Area and Aisle

General Information

Low bay fixtures differ from high bay in that they are optimized for lower mountingheights and wider distribution. Most low bay fixtures are enclosed, using the lens todistribute light evenly as well as to protect the lamp from damage. The maximumwattage of low bay industrial fixtures is usually 400 watts. Typical low-bay luminairesare 70–175 watts.

Low bay luminaires also differ from high bay in that a refractor (lens) is ususallyemployed, both to protect the lamp and to gain higher angle distribution. Unlike thehigh bay, in which luminaires are generally mounted far above the work and accessarea, low bay luminaires are often mounted just slightly above the work area and needfar wider distribution. It is not uncommon for a low bay fixture to have a spacing-to-mounting-height ratio >1.5 (most high bay fixtures are less than 1.5).


One option for replacing low bay HID systems is fluorescent. Conventional industrialfluorescent lighting and low bay HID luminaires are similar in efficiency and CU. A250-watt metal halide lamp will produce about 17,000 mean lumens, about the same astwo F96T12/HO lamps. But with an electronic ballast the fluorescent luminaire usesonly 209 watts, compared to 295 for the HID. Side benefits of the fluorescent includerapid starting, better color and elimination of flicker, and lower LLD. For low bay


4-33

spaces requiring good color, it may be hard to beat electronically ballasted fluorescent.The fluorescent lamps will last longer, too.

For spaces not suited for long fluorescent luminaires, consider low bay luminaires withmultiple compact fluorescent lamps. Products resembling HID luminaires but having 6or 8 26-to 32-watt CFLs are an option to replace 250–400-watt HID luminaires. Withelectronic ballasts, this system offers flicker-free performance, good color, and energyefficiency. Optical properties suffer; so high bay applications of this concept may notwork as well.

It will be difficult to make a simple retrofit of a low bay luminaire. Among the limitednumber of choices, consider direct lamp replacements like the 225-watt and 360-wattmetal halide (energy saving replacements for the 250 and 400); the 325-watt metalhalide (energy-saving replacement for the 400-watt mercury vapor); and the 150-, 215-,360-, and 880-watt high pressure sodium (direct replacement for the 175-, 250-, 400- and1000-watt mercury vapor lamps, respectively). In areas where fine or detailed work isbeing performed, also consider the 250- and 400-watt metal halide replacements for250- and 400-watt HPS. While no energy is saved, visual performance will improve.

HID Vaportight

General Information

Vaportight fixtures, sometimes called “jelly jars,” are a utility industrial luminaire usedindoors and out. There are many related fixtures of similar appearance, such as specialfixtures for petrochemical plants, explosion-proof spaces, and aircraft obstructionlights.


Most vaportight fixtures have only basic optical systems, if any at all. Investigate anyretrofit resulting in equal maintained lumens, being careful to choose systems that willoperate at the temperature extremes expected of the environment. For many normaltemperature range applications, however, look into compact fluorescent replacementsof low-wattage HID luminaires as a primary opportunity. For higher-wattage lamps,see the section on lamp technology and retrofits.


4-34

Special Purposes/Environments

General Information

Industrial luminaires exist for many special applications. Among the most basic typesare wet “wash-down” location luminaires; cold temperature luminaires; vaportight andhazardous environment luminaires; clean room luminaires; and industrial task lights.


In general, the more specialized the environment, the more the retrofitter should beencouraged to carefully upgrade the basic technology with equal lumens, keeping inmind potential pitfalls such as very high or very low starting or operatingtemperatures. A critical concern with specialized applications is the resulting lightlevels and lighting distribution, ensuring that retrofitting look beyond simple lamplumen ratings.

Outdoor

Street and Road Lights

General Information

There are many types of street and roadway luminaires. The two most common are the“cobrahead,” which uses a lens to guide light from an HID lamp to the road andsidewalk, and the “shoebox,” which uses a reflector to do the job. “High mast” lightsare used on tall poles at major freeway intersections, large parking lots, and largeindustrial outdoor areas.

What all of these lighting systems have in common is significantly more engineeringthan most other lighting systems. The precise optics, including lamp position, are usedto calculate lighting levels to determine compliance with relatively rigid guidelines.Changes to the optical system are to be avoided unless carried out with precision andcare.


A large percentage of outdoor street lighting is still using mercury vapor lamps. Specialversions of high-pressure sodium lamps are available as socket-for socket replacements,making it very easy to retrofit without changing the ballast. High-pressure sodiumlamps use about 50–60% of the original mercury vapor watts while producingequivalent lighting levels.


4-35

Other than that, there are no common options for retrofitting most of the existing HPS,metal halide, and LPS street lights that employ high performance luminaires like thecobrahead or shoebox. Decorative street lights, on the other hand, present anopportunity. Ordinary “acorn” and “lollipop” area lights can be replaced with newheads that prevent upward and side radiation, thereby permitting use of a lower-wattage source.

Floodlights and Billboard Lights

General Information

Floodlights are used to illuminate outdoor areas ranging from parking lots to athleticfields. They are also used for other outdoor applications such as lighting a building ormonument. In general, they are metal luminaires with a glass face that are adjustableto aim at the area to be illuminated. Light sources may include incandescent, halogen,fluorescent, compact fluorescent, or HID. Most floodlights are general purpose typeswith wide angle distribution, but specific types are also made with narrow andasymmetric light patterns.

One common variation is the billboard light. These are luminaires designed foruplighting outdoor signs and billboards, and are also used for some types of buildingand wall lighting. Billboard lights are generally either HID or HO fluorescent.


One of the most common floodlights in use is a compact unit using a double-ended,300- to 500-watt tungsten halogen lamp. These luminaires are handy and inexpensive,but use a very low efficacy light source. If used in places where frequent switching andthe need for instant light is common, they remain an acceptable choice; but retrofittingwith HIR lamps is recommended to save energy. The 300-watt lamp is replaced by a225-watt HIR and the 500-watt by a 350-watt HIR, resulting in similar radiated light. Inother cases, compact floodlights with T-5 twin tube lamps up to 55 watts might be usedin their place if a reduction in light level is acceptable and ambient temperatures arenot too low. To maintain similar light levels in long operating period applications, usemetal halide or HPS luminaires of 100–150 watts.

In most commercial applications, HID lamps are already being used. Most energy-saving opportunities are the standard considerations for HID retrofits, such asreplacing mercury vapor lamps or using high-wattage CFLs. But in addition, manygeneral purpose, wide throw floodlights are being used where a luminaire withspecific beam distribution might work better. Consider lower-wattage luminaires with


4-36

a more precise beam pattern. Savings of up to 50% or more may be possible if existinglighting systems waste or spill light into the sky or onto adjacent properties.

In a few cases, fluorescent floodlights and sign lights might be retrofitted withelectronic ballasts. Keep in mind the application’s required starting temperature andselect the ballast accordingly.

Wallpacks

General Information

Wallpacks are typically low-cost, rugged, general purpose luminaires designed to bemounted to a building’s exterior wall and provide area illumination around thebuilding. Most common wallpacks are low-wattage HID or high-wattage compactfluorescent. There are also a number of low-cost incandescent luminaires used for asimilar purpose, often called “wall brackets.”


Keeping in mind starting and operating temperatures and other considerations,evaluate retrofitting most incandescent wall brackets with low-wattage HPS or CFLlamps. Or, retrofit the luminaire with the lowest possible wattage tungsten halogenlamp and install a motion sensor to the luminaire or junction box.

Most HID wall packs are specifically designed for the lamp and chosen to fulfill asecurity or other need. Other than the general retrofits for any HID lamp, it may beworthwhile evaluating the lighting need and the luminaire’s performance. Many HIDwallpacks, especially HPS, produce an unnecessarily high amount of light, and alower-wattage HID or even compact fluorescent luminaire may be acceptable.

Bollards

General Information

Bollards are lighting fixtures, typically about waist-high, used to illuminate walkwaysin parks and near buildings. Decorative bollards may use incandescent or low-wattageHID lamps. Almost all commercial bollards employ low-wattage HID lamps,including mercury vapor, metal halide, and HPS, seldom exceeding 100 watts.


4-37


As with other outdoor lights, incandescent bollards might be retrofit with compactfluorescents provided that the lamp and ballast are appropriate for the temperaturesexperienced in the application. Since most bollards have room to install a ballast,outdoor-rated hardwired ballasts and amalgam compact fluorescent lamps might beused to replace incandescent lamps to 200 watts and HID lamps to 70 watts, dependingon bollard construction and optics. Of course, mercury vapor lamps might also bereplaced with HPS, metal halide or compact fluorescent. Higher-wattage HID bollardsmay not be as suitable for retrofit.

Parking Garage Fixtures

General Information

Parking garages are illuminated either by HID luminaires designed for this use, or bygeneric fluorescent lighting such as strip lights. It is uncommon to find a parkinggarage with incandescent lighting or HID luminaires that are not designed for this use.HID garage luminaires are becoming increasingly sophisticated, with special lensesand reflectors designed for widely-thrown downlight and some uplight for bettervisual comfort. Traditional HID garage luminaires use refractor lenses or facetedreflectors resembling shoebox street lights.


If traditional fluorescent lighting is used, keeping in mind the temperature range of theapplication, consider electronic ballasts possibly with T-8 lamps.

Retrofitting HID systems will require careful analysis and planning. The primaryconcern is the performance of the luminaire’s optical system—different lamp shapes orsource centers might cause the lighting system to work differently. Keeping this inmind, investigate the standard HID retrofit opportunities, especially for mercury vaporgarage lighting systems.

Step Lights

General Information

Step lights and other low-level lights are typically mounted in walls of buildingsaround knee height, with the intended purpose of illuminating the path. Some step


4-38

lights use lenses or reflector lamps to produce specific beam patterns, while othersutilize louvers or lenses to produce general lighting.


Most older step lights are incandescent; so a retrofit will often utilize a CFL. Indoorstep lights are generally in good condition and any suitable CFL adapter might beused. Exterior step lights often have suffered from weathering and may need acleaning and/or replacement of critical parts before retrofitting.

HID step and low-level lights might be retrofit. Investigate the standard HID retrofitopportunities, especially for mercury vapor luminaires. Keep in mind that a higherwattage compact fluorescent (26–42) might be used in luminaires that already haveballast compartments.

Landscape Lights

General Information

There are many types of landscape lights used in a wide variety of residential,commercial, and other applications. Some of the most common are:

x the “bullet” usually used as an uplight for trees

x the “pagoda” and “coolie hat” walklights

x the “tulip” and other styles of planter box lights

x in-ground uplights for trees and statuary


Most landscape lighting is incandescent. Modest retrofits such as using 60-watt HIRPAR-38 lamps in place of 150-watt PAR-38 will be easy, inexpensive, and cost-effective.Similarly, using CFLs of appropriate starting temperature in walklights may also work.New landscape floodlights using compact fluorescent lamps might be used to replaceolder incandescent luminaires.

Occasionally one will find HID or full-sized fluorescent lighting being used inlandscape applications. In addition to the standard considerations for these lamps, itmay help to assess the need for the HID source, or perhaps, to check to see if theluminaire is performing as planned. It is common in outdoor lighting for luminaires tosuffer from weather, and landscape lighting also suffers from irrigation and carelesslandscape maintenance. For example, be sure to check if an in-ground uplight’s lens


4-39

has not been ruined by mineral etching, which would turn a spotlight into a wide floodlamp.

5-1

5 SUMMARY OF RETROFIT OPPORTUNITIES

This chapter presents a summary of lighting retrofit opportunities that should beconsidered. The chapter is intended as a quick reference; only a brief description of therecommended retrofits is presented. More detail is provided in Chapters 3 and 4. Inaddition Chapter 2 presents details on methods that can be used to evaluate theopportunities.

Commercial

Summary of Retrofit Opportunities

5-2


5-3


5-4


5-5


5-6

Industrial


5-7


5-8


5-9

Outdoor

A-1

A GLOSSARY OF TERMS

absolute contrast The difference in reflectance between a visual target and its immediatebackground, without regard to color of target or background.

absorption The dissipation of incident flux within a surface or medium.

accent lighting (highlighting) Light that emphasizes a particular object or objects, or that drawsattention to a specific area within the field of view.

accommodation The process by which the eye changes its focus from one distance toanother.

adaptation The process by which the eye becomes accustomed to varying quantitiesof light or to light of a different color than it was exposed to during animmediately preceding period. Results in a change in the eye's sensitivityto light.

adaptation compensation A lighting control strategy aimed at matching illuminance to the adaptationlevel of the eyes of persons entering the space.

ambiance Mood or feeling in a space, as evoked by that room's lighting system.

ambient lighting Electric and/or natural lighting throughout a space that produces uniformgeneral illumination.

angle of incidence The angle between the normal to a surface and the path of light strikingthe surface.

ANSI The American National Standards Institute.

ANSI conditions The conditions under which most lamps and ballasts are tested for lightoutput, lamp life, etc. Generally means open (a non-enclosed luminaire)conditions, in unmoving air, at 25°C (77°F).

application thermal factor (ATF) A measurement used in lighting calculations to account for the effects of alamp's bulb wall temperature on fluorescent lamp lumen output. ATFvaries depending on luminaire, lamp, and ballast type.

arc discharge A transfer of electricity across two electrodes (anode and cathode),characterized by high electrode current densities and a low voltage dropat the electrode.

architecturally neutral luminaire A luminaire whose design and/or mounting characteristics allow it to beeasily integrated into architectural and interior design schemes.

architecturally positive luminaire A luminaire designed to attract attention to a space and evoke anemotional response; an ornamental or decorative luminaire.

Glossary of Terms

A-2

asymmetric distribution A light distribution pattern in which lumen output is directed more stronglytoward one side than another.

baffle A lamp shielding device that absorbs unwanted light or shields a lightsource from direct view.

ballast A magnetic or electronic device used to control the starting and operationof discharge lamps.

ballast efficacy factor (BEF) A measure of energy efficiency used to establish minimum ballastperformance parameters for component efficiency standards. The figureis determined by dividing the ballast factor by input power. Current federaland state BEFs are in effect for F40T12 and F96T12 ballasts.

ballast factor (BF) The ratio of lamp lumen output on a particular ballast as compared to thatlamp's (lamps') rated lumen output on a reference ballast under ANSI testconditions (free, unmoving air at 25°C).

beam spread A measure used for directional type lamps. The angle between twodirections in any plane in which light intensity (in candlepower) is equal toa stated percentage of the maximum beam intensity. Generally, thepercentage is 10% for flood lamps and 50% for photographic lamps.

black body radiator A temperature radiator of uniform temperature whose radiation in all partsof the electromagnetic spectrum is the maximum obtainable from anytemperature radiator at the same temperature. A black body radiator isused to determine the color characteristics of light sources.

brightness The subjective intensity, as determined by an individual's perceptiveprocesses, of the sensation that results from viewing a light source or asurface or space which directs light into the eyes. Is often used incorrectlyin place of the terms "illuminance" and "luminance."

bulb The glass outer envelope component of a lamp.

bulb wall temperature The temperature at the bulb wall of a lamp, that affects lumen output andinput wattage of fluorescent lamps and that is important in lightingcalculations. See application thermal factor.

candela (cd) A unit of luminous intensity in a given direction, equal to one lumen persteradian.

candlepower (cp) The luminous intensity of a light source, as expressed in candelas.

candlepower distribution curve A curve that represents the varying distribution of luminous intensity of alamp or luminaire.

cathodes See electrodes.

ceiling cavity height In lighting calculations, the distance between the ceiling and the plane ofthe luminaires in a given space.

chromaticity The measurement of a color that includes its dominant wavelength andpurity.

Glossary of Terms

A-3

coefficient of beam utilization The ratio of lumens reaching a specified surface directly from a floodlightor projector to the total quantity of lumens emitted: used principally as ameasurement in exterior applications.

coefficient of utilization (CU) The ratio of lumens from a luminaire received on the work plane to thetotal quantity of lumens emitted by the lamps of that luminaire.

color rendering A general expression for the effect of a light source on color appearanceof objects in comparison with their appearance under a reference lightsource.

color rendering index (CRI) A measurement of the amount of color shift that objects undergo whenlighted by a light source as compared with the color of those same objectswhen seen under a reference light source of comparable colortemperature. CRI values range up to 100.

color temperature The absolute temperature of a blackbody radiator having a chromaticityequal to that of the light source (see correlated color temperature).

component efficiency standards Energy efficiency codes that address the performance of lightingequipment, including lamps, ballasts, and luminaires.

cones Photoreceptor cells located in the fovea of the retina and responsible forcolor (photopic) vision.

continuous spectrum light A light source that radiates at all visible wavelengths of theelectromagnetic spectrum.

contrast The ratio of the luminance of an object to that of its immediatebackground.

cornea The front portion of the eye that receives light and begins the focusing oflight into the eye.

correlated color temperature (CCT) A specification of the color appearance of a light source, relating its colorto that of a black body radiator, as measured in Kelvins (K). CCT is ageneral measure of a lamp's "coolness" or "warmness."

cut-off angle (of a luminaire) The angle between the vertical axis of a luminaire and the first line of sightat which the light source is no longer visible.

daylighting A lighting control strategy that focuses on architectural design practiceand electrical lighting controls to distribute and control natural illuminationand reduce electrical energy use.

demand Refers to the demand for electricity measured as the rate of energyconsumption, usually in kilowatts. See peak demand.

demand-side management (DSM) A series of strategies employed by utilities to manage system load byencouraging customers to manage energy in their facilities.

depreciation See lamp lumen depreciation.

dichroic film A coating applied to glass that reflects light of a specific wavelength whileallowing other wavelengths (usually infrared) to be transmitted.

Glossary of Terms

A-4

diffuse reflection The redirection or "scattering" of incident flux over a range of angles.

diffuser A device that redirects or scatters the flux it receives from a light source.

diffusion See diffuse reflection.

direct glare Glare resulting from insufficiently shielded light sources or areas ofexcessive luminance within the field of view.

direct lighting The use of luminaires that distribute a high percentage of emitted light inthe general direction of the surface to be illuminated. This usually refers tolight emitted downward.

directional lighting Light provided at the illuminated surface predominantly from a preferreddirection. Common accent lighting technique.

disability glare Glare that produces a degradation in visual performance and visibility. Itmay be accompanied by discomfort glare.

discharge lamp A lamp that produces light by discharging an electric arc through amixture of gases and gaseous metals.

discomfort glare Glare that distracts or produces visual discomfort, but which does notnecessarily reduce visibility or visual performance.

discount rate (nominal) The rate at which future benefits or costs are discounted to present valuewith consideration of inflation. When a nominal discount rate is used,future benefits and costs must be quantified in inflated dollars.

discount rate (real) The rate at which future benefits or costs are discounted to present valuewithout consideration of inflation.

display lighting An accent lighting technique that is intended to emphasize artwork ormerchandise. Also refers to specialized lighting equipment thataccomplishes this task.

efficacy A measurement of the ratio of light produced by a light source to theelectrical power used to produce that quantity of light, expressed inlumens per watt. Efficacy is an important determinant of energy efficiencyin lighting equipment.

efficiency See luminaire efficiency.

electrodes Filaments located at either end of a discharge lamp that maintain anelectrical arc between them. See arc discharge.

electromagnetic spectrum A linear representation of all wavelengths of electric and magneticradiation.

ellipsoidal reflector A luminaire or lamp reflecting device in the shape of an ellipse whichredirects light to produce a variable-edged, clearly defined beam.

energy use The total energy consumed over a specific period of time, measured inkilowatt hours (kWh).

Glossary of Terms

A-5

equivalent sphere illumination (ESI) A metric comparing the illumination on a task with that which would fall onthe same task if it were illuminated by a source providing equal luminancein all directions, such as that which would be provided by an illuminatedsphere with the task in the center.

exitance The density of light reflecting from a surface at a point, measured inlumens per square foot (formerly "footlamberts"). It is determined bymultiplying the footcandles striking a diffuse reflecting surface times thereflectance of that surface.

floor cavity height In lighting calculations, the distance between the workplane and the floorin a given space.

fluorescent lamp A discharge lamp in which a phosphor coating transforms ultravioletenergy into visible light.

footcandle (fc) A standard measurement of illuminance, representing the amount ofilluminance on a surface one foot square on which there is a uniformlydistributed flux of one lumen.

footlambert(fl) A measurement of exitance, equal to lumens per square foot. The use ofthis term is no longer popular; exitance should be used instead. Seeexitance.

fovea A region of intense visual sensitivity in the center of the eye's retina,containing only cone type photoreceptors.

frequency The number of waves or cycles of electromagnetic radiation per second,usually measured in Hertz (Hz).

fresnel lens A lens that produces a smooth, soft-edged, clearly defined beam of light.

furniture factor In lighting calculations, a light loss factor that accounts for open-office

furniture systems and other tall partitions.

general lighting Lighting designed to provide a uniform level of intensity throughout aspace. See also ambient lighting.

glare See direct glare, disability glare, discomfort glare, reflected glare.

halogen cycle The process in which a halogen gas combines with tungsten moleculesthat evaporate from the filament during lamp operation and deposits themolecules back on the filament. The halogen cycle, used in tungstenhalogen lamps, reduces lamp lumen depreciation and increases lamp life.

harmonic distortion A corruption of electrical power system characteristics created primarilyby electronic rectifying circuits and high-speed switching systems.

highlighting See accent lighting.

IES/IESNA The Illuminating Engineering Society of North America—a lightingtechnical organization devoted to lighting information and education, aswell as the development of national standards.

Glossary of Terms

A-6

illuminance The density of incident luminous flux on a surface; illuminance is thestandard metric for lighting levels, and is measured in lux (lx) orfootcandles (fc).

illuminance categories An IES recommended series of illuminance categories for a wide varietyof visual tasks; used in lighting calculations to determine illuminancelevels.

illumination The act of illuminating or state of being illuminated. This term is oftenused incorrectly in place of the term illuminance to denote the density ofluminous flux on a surface.

incandescence The emission of visible electromagnetic radiation due to the thermalexcitation of atoms or molecules.

incandescent lamp A lamp in which a filament is heated to incandescence by an electriccurrent, producing visible light.

indirect lighting Lighting strategy in which a large percentage of the light emitted byluminaires is directed toward a surface (usually upward), to be reflectedinto the space to be illuminated.

infrared (IR) radiation Invisible electromagnetic energy within the wavelength range of 770–106

nanometers; may be experienced as radiant heat.

input power The maximum amount of power consumed at any one time by aluminaire-lamp-ballast combination; usually measured in watts.

instant-start operation A mode of starting fluorescent lamps by applying a high voltage to thelamps without preheating the electrodes.

internal rate of return A measure of economic performance representing the percentage of theinitial investment that is returned each year for the life of the investmentthrough energy savings or other benefits.

inverse-square law The law of illuminance that states that the illuminance (E) at a point on asurface varies directly with the intensity (I) of a point source and inverselyas the square of the distance (d) between the point and the source. Atnadir, this relationship may be expressed as: E = Iy d2.

isofootcandle (isolux) line A group of lines plotted on a set of coordinates to show all points on asurface where equal illuminances occur.

kilowatt (kW) A unit of electric power usage, equal to 1000 watts.

kilowatt hour (kWh) A measurement of electric energy. A kilowatt hour is equal to 1000 wattsof power used over a period of one hour.

lamp An electrically energized source of light, commonly called a bulb or tube.

lamp current crest factor A ballast measure that determines the ratio of the peak lamp current tothe root mean square lamp current. High lamp current crest factorsreduce lamp life.

lamp efficacy Ratio of lumens emitted by a lamp to its input power, measured in lumensper watt.

Glossary of Terms

A-7

lamp efficacy standard An energy efficiency standard, basing compliance on minimum lamplumens per watt.

lamp life A measure of lamp performance, as measured in median hours of burningtime under ANSI test conditions.

lamp lumen depreciation (LLD) The decrease over time of lamp lumen output, caused by bulb wallblackening, phosphor exhaustion, filament depreciation, and other factors.

lamp starting Generic term used to describe a discharge lamp's starting characteristicsin terms of time to come to full output, flicker, etc.

lens A glass or plastic luminaire component used to control the direction anddistribution of emitted light.

light loss factor (LLF) A multiplier used in lighting calculations to account for degradation ofANSI-rated lamp lumens. Accounts for temperature and voltagevariations, various depreciation factors, and environmental operatingconditions.

light trespass The distribution of light into unwanted areas due to a lack of shielding orbeam control, or because of poor lighting design.

lighting energy The quantity of electricity used for lighting, measured by multiplyingconnected lighting load by time of operation.

lighting power density (LPD) A metric of interior lighting power use, usually measured in watts persquare foot; a popular measurement in the determination of lightingenergy efficiency for codes and standards.

lighting power density standards Energy efficiency standards that base lighting compliance on connectedlighting load in watts per square foot.

line spectra light source A light source consisting of a very limited section of the visibleelectromagnetic spectrum, resulting in a light in which one color isdominant.

louver A light source shielding device consisting of a geometrically patternedseries of baffles, designed to shield or absorb unwanted light that is visiblefrom certain angles.

lumen The quantity of luminous flux emitted within a unit solid angle (onesteradian) by a point source with one candela intensity in all directions.

lumen maintenance A lighting control strategy that uses a photocell to detect illuminancelevels in a space and maintain the lighting levels at the design illuminancelevel throughout the life of the lamps. Generally, this means that lampsare operated at a dimmed level when new. Over time, as lamps age anddepreciation occurs, power to the lamps is gradually increased.

lumen method An interior application lighting design procedure used to determine therelationship between the number and types of lamps and luminaires, theroom characteristics, and the average illuminance on the workplane.Accounts for both direct and reflected light. Sometimes known as zonalcavity computation.

Glossary of Terms

A-8

luminaire A complete lighting unit, consisting of a lamp or lamps together with thecomponents required to distribute the light, position the lamps, andconnect the lamps to a power supply. Often referred to as a "fixture."

luminaire dirt depreciation (LDD) A multiplier used in lighting calculations to account for the reduction inilluminance produced by the accumulation of dirt on a luminaire.

luminaire efficiency The ratio of lumens exiting a luminaire to the total lumens emitted by thatluminaire's lamps; expressed as a percentage.

luminance The luminous intensity of a surface in a given direction per unit area ofthat surface as viewed from that direction; often incorrectly referred to as"brightness."

luminance ratio The ratio between the luminances of any two areas in the visual field.

lux (lx) A standard unit of illuminance. One lux is equal to one lumen per squaremeter.

net present value The sum of the initial costs and all future costs and benefits, discounted topresent value.

neural adaptation adjustment Changes in the brain that occur when the visual system is exposed todifferent light levels.

non recoverable light loss factors Losses in luminaire lumen output that are not due to depreciation factors.Nonrecoverable factors include ballast and thermal factors.

occupancy sensing A lighting control strategy that switches lighting systems on or off basedon the presence or absence of persons in a controlled space.

off-peak energy use Energy consumption during off-peak hours; usually during the lateevening and early morning hours.

on-peak energy use Energy consumption during the period of peak demand; usually definedas early afternoon to early evening during the summer months.

parabolic reflector A lighting distribution control device that is designed to redirect aluminaire's light in a specific direction. A parabolic reflector may be acomponent in either a lamp or a luminaire. In most applications, theparabolic device directs light down and away from the direct glare zone. Influorescent luminaires, parabolic reflectors are often combined withlouvers to minimize glare and redistribute light. With more direct lightsources, such as incandescent A lamps, the reflector usuallyaccomplishes these actions without the use of louvers.

particle theory The conceptualization of electromagnetic energy as a stream of particlesor "photons" traveling in a linear direction.

peak demand A utility customer's maximum load. For purposes of calculating utility cost,peak demand is generally based on the maximum monthly demand,where demand is measured as an average over a time interval, usually 15or 30 minutes. See demand.

Glossary of Terms

A-9

peak demand limiting A lighting control strategy that focuses on the gradual dimming of electriclights during times of on-peak energy use, typically from early afternoon toearly evening during warm weather months. This strategy has the addedbenefit of reducing air-conditioning loads during these hours.

phosphorescence Light emitted due to the absorption of radiation and resultant excitation;this luminescence continues for a period of time after excitation.

photocell/photosensor A device that measures the amount of incident light present in a space.

photometry The measurement of light quantities.

photon A particle of electromagnetic radiation.

photopic vision Vision produced by the cone receptors in the retina. Responsible for colorvision.

photopigments Chemicals within the eye whose quantities change with the amount of lightentering the eye at any one time.

point source A light source with dimensions that are small enough, in relation to thedistance between the light source and the lighted surface, that thedimensions of the source may be excluded from calculations. Refers, inmost cases, to compact incandescent or HID light sources used inapplications requiring a high degree of control over the beam spread ofthe light source.

power adjustment factor An assumed reduction in lighting power to account for the effect ofautomatic lighting controls. Power adjustment factors are specified inmany energy efficiency standards.

power draw See input power.

power factor A measurement that determines how effectively input power is convertedinto actual usable power by an electric component such as a ballast. InAC circuits, some of the current drawn by an electrical device is wasted.Power factor is determined by computing the ratio of input watts to rootmean square of the volt-amps of the electrical component. Utilities mayelect to penalize customers whose electric load has a low power factor(usually less than 0.90).

prime colors of light The three colors—red, green and blue—that produce white light whenadded together in equal proportions.

prism A device that bends light through the principle of refraction.

prismatic lens A lens that uses refraction to redirect light rays.

pupil The adjustable aperture in the iris of the eye that regulates the quantity oflight admitted into the eye.

rapid-start operation A method of starting fluorescent lamps in which the ballast provides aseparate winding for the constant heating of the lamp's electrodes. Rapid-start ballasts enable starting without the need for a starter switch or theapplication of high voltage.

Glossary of Terms

A-10

reactor ballast A ballasting device used primarily with low-wattage lamps or in high-power(non-120-volt) industrial applications. These simple inductor devicesconsist of a choke coil and starter, wired in series with the lamp. Someare available with power-factor-correcting capacitors. The primaryadvantage to using reactor ballasts is that they are inexpensive. However,they regulate lamp power poorly.

recoverable light loss factors Losses in luminaire light output that can be regained through relampingand maintenance.

reflectance The ratio of reflected flux to incident flux.

reflected glare Glare resulting from specular reflections of high luminance in polished orglossy surface within the visual field.

reflection The process by which incident flux leaves a surface from the incident sidewithout a change in frequency.

reflector A device used to direct the light from a source through the process ofreflection.

refraction The process by which the direction of a ray of light changes as it passesfrom one medium to another, due to a change in its speed.

relative visual performance (RVP) A complex measurement that determines the probability (percent) ofsuccessfully performing a particular visual task under a very specific set ofconditions. RVP is especially useful for assessing task visibility underconditions where speed and accuracy are important to successful visualperformance.

re-strike time A delay in lamp starting that occurs after a momentary power interruption;applicable to all high-intensity discharge lamps, as well as to cathodecutout fluorescent lamps.

retina The cell lining at the back of the eye containing photoreceptors (rods &cones) and nerve cells that link to the optic nerve.

rods Photoreceptor cells located in the retina and very responsive to low levelsof light.

room cavity height In lighting calculations, the distance from the workplane to the plane of theluminaires.

room cavity ratio (RCR) In lighting calculations, a measure of room proportion as determined bydimensions of length, width, and height.

room surface dirt depreciation (RSDD) A light loss factor produced by the accumulation of dirt on room surfaces.

scheduling The controlling of electric light through the use of manual or automaticswitching.

scotopic vision Vision produced by the eye's rod receptors. Enables the eye to discernblack and white contrast—also referred to as night vision.

shielding The blocking of a light source from direct visibility.

Glossary of Terms

A-11

simple payback A measure of economic performance representing the number of yearsrequired for the monetary value of the energy savings to equal theinvestment. Simple payback may be adjusted to consider other annualsavings and costs such as maintenance expenses.

spacing to mounting height ratio The ratio of the distance between luminaires in a common space to theirmounting height above the workplane. Used to help achieve uniformity ofilluminance. Technically, spacing criteria (SC) provides better results.

sparkle lighting A lighting design technique using point sources of light whereby the lightsource itself becomes the display or attraction.

specular reflection The redirection of incident light without diffusion at an angle that is equalto and in the same plane as the angle of incidence.

steradian A unit solid angle on the surface of a sphere equal to the square of thesphere's radius.

sweeping The automatic switching off of lights throughout an entire building at apreset time or times.

task lighting Lighting that is directed to a specific surface or area to provide illuminationfor visual tasks.

task-ambient lighting A combination of task and ambient lighting designed so that the level ofambient light is less than and complementary to the task lighting.

time of use, time of operation A time measure that is multiplied by the measure of connected power toquantify energy use.

transient adaptation The process by which the eye adjusts to different levels of illuminancewhile moving from space to space.

transmission The process whereby incident flux passes through a surface or medium toemerge on another side—a characteristic of transparent or translucentmaterials, such as glass and plastic.

transmittance The ratio of transmitted flux to incident flux.

troffer A common recessed luminaire type, usually installed with the openingflush with the ceiling.

tuning The control of electric light through the use of dimming equipment.

ultraviolet (UV) radiation Invisible electromagnetic radiation within the wavelength range of 10 to380 nanometers.

veiling luminance A luminance superimposed on the retinal image which reduces itscontrast, resulting in decreased visibility and visual performance;produced by areas of increased intensity in the visual field.

veiling reflection A reflection on the visual task that obscures visibility by reducing contrast(see veiling luminance).

vertical footcandles A measurement of illuminance intensity on a vertical surface, such as awall or billboard.

Glossary of Terms

A-12

visible light Electromagnetic radiation within the wavelength range of 380–770nanometers.

visual comfort The absence of discomfort glare within the visual field.

visual comfort probability (VCP) A lighting system rating metric that determines the probable percentage ofpeople who would find the lighting to be free of discomfort glare, whenviewed from a specified location and in a specified direction.

visual field The location of objects or points in space that can be perceived when thehead and eyes are kept stationary.

visual performance An assessment of the ability to perform a visual task, taking speed andaccuracy in account.

visual surroundings All portions of the visual field with the exception of the visual task.

visual task The details and objects that must be seen for the performance of a givenactivity; this includes the immediate background of the details or objects.

watt (W) A unit used to measure electric power. One watt equals one joule/sec.

wave theory The conceptualization of electromagnetic energy moving from a source oforigin in the shape of a wave.

wavelength The distance between two successive points of a periodic wave, in whichthe oscillation has the same phase; for electromagnetic radiation, thedistance is generally measured in micrometers or nanometers.

wayfinding The placement of luminaires so as to define the location of pathways,doors, etc.

workplane The plane at which work is usually performed and on which illuminance iscalculated and specified; generally assumed to be a horizontal plane atdesk height (0.76 meters [30"]).

B-1

B BIBLIOGRAPHY

EPRI Reports and Fact Sheets

Lighting Bulletins, Handbooks, and Reports

The Value of Lighting System Maintenance, MI-101838, 9/92

Visual Display Terminal Lighting, MI-101855, 3/93

Lighting Quality, MI-101857, 3/93

It Pays to Turn Off the Lights, MI-102565, 4/94

Lighting Systems Performance, MI-102565, 4/94

Calculating Lighting and HVAC Interactions for Commercial Offices, MI-103646, 4/94

Retrofitting Four-Lamp Troffers, MI-105193, 4/95

How Many Footcandles Do I Really Need? MI-105223, 8/95

Leased Outdoor Lighting, MI-107067, 10/96

LED Exit Signs, MI-108325, 6/97

Electronic Ballasts Prove Successful in Healthcare Facilities, MI-108352, 6/97

Advanced Lighting Technologies for Health Care, MI-108407, 7/97

Electrodeless Lamps and their Applications, MI-108400, 7/97

Lighting Controls: Lessons from the Field, MI-108399, 7/97

Selecting Outdoor Luminaires, MI-109752, 1/98

Lighting the Office Environment, EPRI Journal Reprint, JR-105556, 5/95

Bibliography

B-2

Commercial Lighting Efficiency Resource Book, CU.7427, 9/91

Performance Evaluation of Energy-Efficient Lighting and Office Technologies in New YorkCity, TR-108366, June 1997

Lighting Fundamentals Handbook, TR-101710, 12/92

Lighting Controls: Patterns for Design, TR-107230, 12/96

Daylighting Design: Smart and Simple, TR-109720, 12/97

Applications

Photoelectric Control of Daylighting-Following Lighting Systems, Report CU.6243, 3/89

1994 Commercial DSM Survey (Including Utility Lighting Programs), TR-105685, 11/95

Advanced Lighting Guidelines, TR-101022-R1, 5/93

Videotapes

Office Lighting Design, EM86-05, 5/86

Brochures

Retrofit Lighting Technologies, CU.3040R1, 4/93

HID Lighting, BR-101739, 1993

Fact Sheets

Compact Fluorescent Lamps, CU.2042R, 4/93

Specular Retrofit Reflectors, CU.2046, 10/91

Occupancy Sensors, BR-100323, 4/92

Electronic Ballasts, BR-101886, 5/95

Software

LightCAD version 2.0, NATS# 7893

Bibliography

B-3

LREP version 1.0, NATS# 7939

LightPAD version 2.0, NATS# 25694

BEEM version 1.0, NATS# 18824

(Available from Electric Power Software Center (800) 763-3772)

IESNA Publications:

General

IES Lighting Handbook

IES Lighting Education:

Lighting Education Fundamentals, ED-100

Intermediate Level Lighting Course, ED-150

Lighting Mathematics, ED-200.1-88

Recommended Practices

Office Lighting (Incorporates RP-24 Recommendations; ANSI Approved), RP-1-93

Educational Facilities Lighting, RP-3-88

Light Energy Management

Design Considerations for Effective Building Lighting Energy Utilization, LEM-3-87

Other Publications:

K. Johnson and R. Zavadil. “Assessing the Impacts of Non-linear Loads on PowerQuality in Commercial Buildings—An Overview.” IEEE Transactions, May 1991.

R.A. Rundquist, K. Johnson, D. Aumann.“Calculating Lighting and HVACInteractions.” ASHRAE Journal, November 1993, Vol. 35, No. 11.

“Compact Fluorescent Product Guide.” Energy User News, September 1997, Vol. 22,No. 9.

Bibliography

B-4

B. Collins, S. Treado, and M. Ouellette. “Evaluation of Compact Fluorescent LampPerformance at Different Ambient Temperatures.” National Institute of Standardsand Technology. NISTR 4935.

J. Friedman and D.E. Weigand. “Lighting Controls for Managing Energy.” LightingDesign + Application, February 1992.

“Lighting Equipment and Accessories Directory.” Lighting Design + Application,February 1994. Vol. 24, No. 2.

“Standard for Safety.” Fluorescent Lighting Fixtures, Underwriters Laboratories,Inc., Santa Clara, CA. UL 1570.

M.S. Rea. “Switch the Lights Off!” Lighting Design + Application, December 1986.

Naval Construction Battalion. “Turn Off the Lights!” Port Hueneme, January 1980,Tech Data Sheet 80-01.

S. Gould. “Utilizing Advanced Lighting Technology Options.” Stanford University,Proceedings from the Association of Energy Engineers Lighting Efficiency Congress 90,March 27–30, 1990.

R. Abesamis, P. Black, and J. Kessel, " Field Experience with High-FrequencyBallasts." IEEE Transactions On Industry Applications, September/October 1990, Vol.26, No. 5.

American Institute of Architects. Healthy Productive Buildings: A Guide toEnvironmentally Sustainable Architecture.

California Energy Commission. Directory of Certified Fluorescent Lamp Ballasts andCertified Luminaire Manufacturers. April 1985 (revised).

D.K. Smith and Associates. Comparison of Light Output from Compact Fluorescent andIncandescent Lamps. Stoneham, MA.

Damon Wood, Lighting Upgrades: A Guide for Facilities Managers, UpWardPublications, Inc., ISBN: 1-57730-425-x, 1995.

Denis O'Connor. "Measuring Results for a Corporate Lighting Efficiency Program."Energy Engineering, 1993, pp. 14–23, Vol. 90, No. 6.

Douglas Myron and Ken Shelton. "Occupancy Sensors." Proceedings of the North TexasAssociation of Energy Engineers, May 13–14, 1991.

Bibliography

B-5

Francis Rubinstein, Automatic Lighting Controls Demonstration: Long-Term Results.Pacific Gas & Electric, July 1991. Report 008.1-91.

Joseph J. Romm, Lean and Clean Management: How to Boost Profits and Productivity byReducing Pollution. Kodansha: New York, 1994.

J. Kessel, "Performance of Retrofit Optical Reflectors." Strategic Planning for Energyand the Environment, Fall 1990, Vol. 10, No. 2.

John L. Fetters, The Handbook of Lighting Surveys and Audits, CRC Press, ISBN: 0-8019-8873-x, 1998.

Lawrence Berkeley Laboratory. Performance of Electronic Ballasts and Other NewLighting Equipment. Electric Power Research Institute, March 1986, EM-4510.

Lighting Research Center. Specifier Reports (series). New York, 1992–1995.

Lithonia Lighting. Specular Materials in Recessed Fluorescent Luminaires. Georgia, 1991.

Michael Siminovich and Chin Zhang. "Increasing Fixture Efficiency with ConvectiveVenting in Compact Fluorescent Downlights." Energy Engineering, 1993, Vol. 90, No.6, 1993, pp. 24–32.

M. Siminovitch, F. Rubinstein, and R. Whiteman. “Thermal PerformanceCharacteristics of Compact Fluorescent Fixtures.” Lawrence Berkeley Laboratory,Proceedings from the Association of Energy Engineers Lighting Efficiency Congress 90,March 27–30, 1990.

Underwriters Laboratories, Inc. Fluorescent Lighting Fixtures. UL 1570, 1995.Describes standards for new fixtures.

Underwriters Laboratories, Inc. Electrical Construction Materials 1990 Directory, pp.126–128 (retrofit conversion kits).

Walter Kroner et al. Using Advanced Office Technology to Increase Productivity. Centerfor Architectural Research, Rensselaer Polytechnic Institute, 1992, p. 4.

Associations, Societies, and Institutes

American Consulting Engineers Council (ACEC), 1015 15th Street, NW., Suite 802,Washington, DC 20006

Bibliography

B-6

American Institute of Architects (AIA), 1735 New York Avenue, N.W., Washington,DC 20006

American Institute of Plant Engineers (AIPE), 8180 Corporate Park Drive, Suite 305,Cincinnati, OH 45242

American National Standards Institute (ANSI), 11 West 42nd Street, New York, NY10036

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.(ASHRAE), 1971 Tullie Circle, N.E. Atlanta, GA 30329

Association of Energy Engineers (AEE), 4025 Pleasantdale Road, Suite 420, Atlanta, GA30340

Building Owners and Managers Association International (BOMA), 1250 I Street N.W.,Suite 200, Washington, DC 20005

Certified Ballast Manufacturers Association (CBM), 1422 Euclid Avenue, Suite 402,Cleveland, OH 44115

Edison Electric Institute (EEI), 701 Pennsylvania Avenue, N.W., Washington, DC20004

Electric Power Research Institute (EPRI), 3412 Hillview Avenue, Palo Alto, CA 94304

EPRI Lighting Information Office (LIO), 501 Fourteenth Street, Suite 200, Oakland, CA94612

Energy Management and Controls Society, 1925 North Lynn Street, Arlington, VA22209

Illuminating Engineering Society of North America (IESNA), 120 Wall Street, 17th Floor,New York, NY 10005-4001

Institute of Electrical and Electronics Engineers, Inc. (IEEE), 345 East 47th Street, NewYork, NY 10017

Institute of Environment Sciences, 940 E. Northwest Highway, Mt. Prospect, IL 60056

Institute of Industrial Engineers, 25 Technology Park, Atlanta, Norcross, GA 30092

Instrument Society of America (ISA), P.O. Box 1277, Research Triangle Park, NC 27709

Bibliography

B-7

International Association of Lighting Designers (IALD), 1133 Broadway, Suite 520, NewYork, NY 10010

International Association of Lighting Management Companies (IALMCO), 431 Locust,Suite 202, Des Moines IA 50309

Manufacturers of Illuminating Products, 158-11 Harvey Van Arsdale, Jr. Avenue,Room 307, Flushing, NY 11365

National Association of Electric Distributors (NAED), 45 Danbury Roda, Wilton, CT06897

National Electric Contractors Association, Inc. (NECA), 3 Bethesda Metro Court, Suite1100, Bethesda, MD 20814

National Electrical Manufacturers Association (NEMA), 1300 N. 17th St. Suite 1847,Rosslyn VA 22209.

National Institute of Building Science (NIBS), 1201 L Street, N.W., Suite 400,Washington, DC 20005

National Lighting Bureau (NLB), 1300 N. 17th St. Suite 1847, Rosslyn VA 22209.

National Society of Professional Engineers (NSPE), 1420 King Street, Alexandria, VA22314-2794

The Electrification Council (TEC), 701 Pennsylvania Avenue N.W., Washington, DC20004

Ordering Information

Electric Power Research Institute3412 Hillview AvenueP.O. Box 10412Palo Alto, CA 94303(415) 855-2411

To order EPRI reports or brochures,contact:EPRI Distribution Center207 Coggins Drive

To order EPRI software, contact:Electric Power Software Center(800) 763-3772

For EPRI-member lighting support,contact:EPRI Lighting Information Office(800) 525-8555Fax (510) 444 2072email: [email protected]

Bibliography

B-8

P.O. Box 23205Pleasant Hill, CA 94523(510) 934-4212FAX (510) 944-0510

For general customer systems support,contact:Customer Assistance Center(800) 766-EPRI

C-1

C EPRI’S LIGHTING ANALYSIS TOOLBOX

EPRI, in collaboration with its utility partners, has assembled the Lighting AnalysisToolbox, an integrated set of software tools that address a number of the importantissues necessary for high-quality lighting retrofits.

Lighting Audit Software: LightPAD 2.0

LightPAD 2.0 is a flexible auditing tool providing a range of capabilities—from quickestimates of a building’s lighting energy use to detailed analysis based on on-site dataentry. Users can input a range of variables—such as lighting components, hourlylighting use levels, and energy rates. Alternative lighting systems can be identified andcompared while still at the site. In addition, users can compare lighting power densityin each space to the recommendations of ASHRAE/IESNA Standard 90.1—1989. Datacan also be exported to the EPRI COMTECH program (see below) when more complexfinancial analyses are needed. Database tables supplied with LightPAD contain typicallighting schedules and generic fixtures with average performance and estimated costdata. Users can customize the libraries to include additional schedules, luminaires, andother data. LightPAD 2.0 is designed to run on an IBM PC operating Windows 3.1 orhigher. Windows for Pen Computing 1.0 is incorporated, which supports “pen” andkeyboard entry.

Daylighting Analysis: Building Energy Estimation Module (BEEM)

BEEM is a simplified computer program that predicts daylighting and window impactson building lighting and energy economics. The program provides data to helpdesigners decide whether to include lighting controls, such as dimmers, for daylightingand what, if any, glass and shading options are cost effective. The user inputsinformation about the space to be lit, such as illumination required, location,dimensions, exposure, window size, shading coefficient, and shading options. BEEMthen calculates the typical daylight illumination and the cost of lighting controls tocomplement that illumination. It then determines measure costs and energy savings.The final result is an analysis of the cost of daylighting controls versus the savings theywill yield. BEEM runs on an IBM PC or compatible under DOS.

EPRI’s Lighting Analysis Toolbox

C-2

Lighting and Other Building Systems: COMTECH

COMTECH is a DOS-based interactive screening tool for evaluating the cost impacts ofa variety of building system technologies. The logic of COMTECH is straightforward:The user inputs a compact set of data, and the system determines equipment andoperating costs based on the data. The input data encompasses (1) building energy-usepatterns, including lighting, cooling, and heating; (2) electric and gas rate structures; (3)equipment efficiencies; and (4) measure costs. COMTECH then combines the inputsand estimates the system costs, monthly energy bills, and operating costs. The user canvary the input data, especially the equipment efficiency and costs, to formulate “whatif” scenarios when considering different retrofit options. For example, to analyze ahospital considering lighting upgrades, LightPAD and BEEM can be used to identifythe upgrade possibilities. Then these proposed upgrades and energy information fromthe other building systems are loaded into COMTECH to determine which scheme ismost effective.

Lighting Evaluation System (LES)

LES is a system of intelligent software and data logging hardware that automates theprocess of collecting data and transforming it into useful information. The LES dataloggers can be used to monitor illuminance, occupancy, electric current, temperature,and other conditions. The software will help determine the number of data loggers toinstall and where they should be installed. Based on short-term monitoring data, LESwill develop lighting load profiles (times of day lighting is used) and determine loadshapes that can be used to predict annual energy and demand savings from retrofits.LES also considers interactions with the HVAC system. LES will help develop a datacollection plan from a description of the lighting system; initialize a suite of small,battery-powered data loggers; download the data at the end of the monitoring period;and automatically perform the data analysis. Data are plotted using the graphingfeatures built into LES. The LES software runs under Microsoft Windows.

Post-Retrofit Calibration and Commissioning: Lighting Diagnostics andCommissioning System (LDCS)

The LDCS is a complete hardware and software package designed for post-retrofitcommissioning and calibration of sensitive controls such as dimmers and occupancysensors. It performs diagnostics and feasibility studies on lighting control systemsthrough the use of short-term monitoring. LDCS streamlines diagnostics by:

x structuring the procedure that specifies the lighting control systems to be tested

x specifying the instrumentation or data logger requirements for the test

x handling all communication with the data loggers

EPRI’s Lighting Analysis Toolbox

C-3

x automatically performing calculations

x presenting the data in graphic from

x preparing reports for the monitoring project

LDCS can be used with dimmers to determine if the electric lights are being dimmed asthe daylight level increases, and if sufficient illuminance is being maintained in thezone as the lights are dimmed. It can be used with occupancy sensors to determine ifthe sensors are turning lights on and off to maximize energy savings, and if an areawithout an occupancy sensor could benefit from one. LDCS also diagnoses lightingsweep systems. LDCS operates with Windows 3.1 or higher.

D-1

D CALCULATING ILLUMINATION LEVELS

Lighting calculations may be used as an alternative to measurements to determinelighting levels in a space and to assess whether it is overlighted or underlighted.Outdoor lighting levels can also be calculated using standard calculation methods. Thisappendix provides information on two methods of calculating lighting levels.

x The lumen method may be used to calculate average illumination levels for interiorspaces. This is the method used by LightPAD 2.0.

x Point source calculations may be used to assess illumination levels for parking lotsand other outdoor spaces.

A more complete presentation of lighting calculations is provided in EPRI’s LightingFundamentals Handbook, TR-101710 and the IESNA Lighting Handbook.

The Lumen Method

The lumen method, also called the zone cavity method, is the most widely used methodfor calculating interior illumination levels or determining the number of luminairesnecessary to achieve a design illumination level. Lumen method calculations assume auniform distribution of luminaires and diffuse surface reflectances for the walls,ceiling, and floor of the space. The lumen method is based on average illuminance atthe workplane and does not provide information on the distribution of light within thespace or the brightness of surrounding surfaces. Generally, lumen method calculationsare limited to rectangular rooms; but with some modification, they can be used with L-shaped and round rooms. The lumen method offers little information about theuniformity of illumination. To overcome this limitation, luminaire manufacturersusually provide recommendations on spacing criteria or spacing-to-mounting heightratios to help insure acceptable uniformity of illumination in the space. This value isusually given along with the data contained in CU tables.

Consider a theoretical room, with 100% diffuse reflection from all the surfaces, andilluminated by luminaires capable of delivering all the lamp lumens to the worksurface. The illuminance in lumens/sq. ft.(fc) at the workplane would be the sum of allthe lamp lumens divided by the area of the workplane. This is the underlying basis ofthe lumen method and can be expressed in the following equation.

IlluminanceLumens

Luminaire

No. of Luminaires

Area= × = Lumens

Area

Calculating Illumination Levels

D-2

Of course the room surfaces absorb some of the light, and some is lost in the luminaire;so an adjustment is made. This adjustment is the coefficient of utilization (CU). The CUis based on the size and shape of the room, the surface reflectances, and the design ofthe luminaire. Manufacturers publish tables of CUs with their product literature. Otheradjustments are made as well, to account for the depreciation of light output over time,the accumulation of dirt on the luminaires and the room surfaces, and differencesbetween rated and actual lamp lumens. These other adjustments are collectivelyreferred to as the light loss factor (LLF). The basic equation for the lumen method thenbecomes:

IlluminanceLumens

Luminaire

No. of Luminaires

Area= × × ×CU LLF

Lighting designers are usually more interested in how many luminaires are needed todeliver a specified level of illumination. For this purpose, the equation can berearranged as shown below.

Luminaires Illuminance Area

LumensLuminaire

CU LLF= ×

× ×

Coefficient of Utilization (CU)

Coefficients of utilization are published by luminaire manufacturers in tabular formsimilar to Table Table D-1. A separate table for each luminaire design gives CU valuesbased on the floor, ceiling, and wall reflectances, and the room cavity ratio (see TableTable D-1). Typical surface reflectances are 80/50/20 for the ceiling, wall, and floorrespectively (shown in gray).

Table D-1Coefficients of Utilization for 2'x4' Parabolic Troffer with Three F40T12 Lamps

Floor Reflectance 20%

Ceiling Reflectance 80% 70% 50%

Wall Reflectance 70% 50% 30% 10% 70% 50% 30% 10% 50% 30% 10%

Room Cavity Ratio

0 74 74 74 74 73 73 73 73 70 70 70

1 71 69 67 66 69 68 66 64 65 64 62

2 67 63 61 58 65 63 60 58 60 58 56

3 63 58 55 52 71 58 54 52 57 53 51

4 59 53 50 47 58 53 49 46 51 48 46

5 55 49 45 42 54 49 44 41 48 44 41


D-3

Room Cavity Ratio

The room cavity ratio (RCR) accounts for the fact that CU values are influenced by thesize and shape of the room. For rectangular rooms the RCR can be calculated by thefollowing equation, where H is the room cavity height, L is the room length, and W isthe room width.

RCR = 5 H (L + W)

L W

× ××

Room cavity height is the distance from the bottom of the luminaires to the workplane.It should not be confused with the ceiling height. For recessed luminaires, the roomcavity height is the ceiling height less the height of the workplane (usually 2.5 ft). Largeopen offices typically have an RCR of about 1.0, while private offices have an RCR ofabout 5.0. The larger the RCR, the more difficult it is to light the room, by virtue of itssize and shape.

For "L" shaped, round, or other odd-shaped rooms the RCR equation may begeneralized by substituting the perimeter (P) for (L + W) and room area (A) for L x W.This form of the equation is given as follows:

RCR H P

A=

.2 5× ×

For pendant-mounted luminaires, including indirect and direct/indirect luminaires,the ceiling cavity (the space between the luminaires and the ceiling) as well as the roomcavity must be considered in determining the ceiling reflectance. This and many otherissues are discussed in detail in the IES Lighting Handbook.

Light Loss Factor

Light Loss Factor (LLF) is a fractional multiplier with a value between zero and onethat adjusts the rated lamp lumens for depreciation of light output over time, as well aslight loss due to environmental and equipment factors. Light loss factors may berecoverable or nonrecoverable.

Most recoverable light losses result from lamp lumen depreciation and theaccumulation of dirt on luminaire components and room surfaces. These losses arerecoverable through relamping and cleaning. Lumen method lighting calculationsgenerally account for recoverable light losses by designing for a "maintained"illuminance level. This means that at the beginning of luminaire maintenance periods,there is an excess of light, unless special controls are employed. The design level of


D-4

illuminance is reached only after lamp lumens have depreciated and dirt hasaccumulated.

Nonrecoverable light loss factors are created through the interactions inherent inluminaire-lamp-ballast systems. They affect lumen output throughout the life of theluminaire. The most significant examples of nonrecoverable light loss factors includethe ballast factor and application thermal factor.

The overall LLF is calculated by multiplying the individual light loss factors together asshown in the following equation. A more complete description of individual light lossfactors follows.

LLF = LLD u LDD u RSDD u BF u ATF u FF

Where

LLD Lamp Lumen Depreciation is the reduction of lumen output produced by bulb wall blackening, phosphorexhaustion, filament depreciation, and other factors related to the aging of lamps. Metal halide andmercury vapor lamps depreciate the most; high-pressure sodium and tungsten halogen the least. This is arecoverable factor, meaning that lumen output increases every time new lamps are installed. Commondepreciation values are about 0.88 (12% loss) for RE-type fluorescent lamps and about 0.84 for standardhalophosphor fluorescent lamps (see Chapter 5 for information on fluorescent lamps phosphors). If agroup relamping and maintenance program is planned, a higher LLD can be assumed, and fewer lamps orluminaires may be required to provide the necessary light levels.

LDD Luminaire Dirt Depreciation is the natural accumulation of dirt on lamps, lenses, and reflecting surfaces.Obviously, the greatest reductions occur in dirty or dusty environments. This is also a recoverable factor,and more frequent cleaning will minimize the effect.

RSDD Room Surface Dirt Depreciation, another recoverable factor, is the natural accumulation of dirt on ceilingsand walls. This reduces room reflectances, which in turn lowers a luminaire's CU value. This factor isusually insignificant unless indirect lighting is used; a common value for direct lighting in offices is 0.98, or2% loss. Typical values for indirect luminaires range from .60 to .90 at RCR values of 1 or less.

BF Ballast Factor accounts for the relationship between lamps and ballasts, especially for fluorescent lighting.Ballasts are usually designed so that lamps produce slightly less than their rated output. Ballast factor is anonrecoverable light loss. For standard "energy-saving" magnetic ballasts, the factor averages about 0.925for standard F40T12 lamps and 0.87 for 34-watt energy saving lamps. For 32-watt T-8 lamps with instant-start electronic ballasts, 0.95 is a typical ballast factor.

ATF Application Thermal Factor accounts for the fact that lamp lumen output is very sensitive to the lamp's bulbwall temperature. Lamp lumen ratings are made under very specific ANSI operating conditions: in free,unmoving air at a temperature of 25°C (77°F). A lamp's bulb wall temperature can be significantly higherinside a luminaire. For example, in a magnetically ballasted static, lensed troffer, lumen output of 40-wattF40T12 lamps will be reduced by about 6% due to the elevated temperature. ATF varies depending onluminaire, lamp, and ballast type. Lamps operated by electronic ballasts, for instance, are somewhat lesssensitive to variations in bulb wall temperature. Photometric data by luminaire manufacturers partiallyaccounts for non-ANSI operating conditions. The Advanced Lighting Guidelines (TR-101022) provideluminaire tables that account for the effects of both the ATF and the ballast factor on lamp lumen output.See the Luminaires and Lighting Equipment chapter of that document for details.


D-5

FF Furniture Factor accounts for light loss due to open-office furniture systems and other tall partitions. Intraditional office spaces without vertical partitions, the factor is 1.00 (no loss); for 60-inch tall partitionsystems, the factor is 0.70. This factor is nonrecoverable, unless the partitions are removed.

Point Source Calculations

Point source calculations are used primarily for determining the effect of one or moreluminaires in an outdoor setting. Calculations are based on the inverse-square law ofillumination. The inverse-square law says that the illuminance on a surface is inverselyproportional to the square of the distance from the light source to the target. Theilluminance is also dependent on the incident angle at which light strikes the surface.These relationships are shown in the following equation.

E I x ine

d=

cos θ2

E is the illuminance on the surface in footcandles (lux), I is the candlepower, incandelas, of the light source in the direction of the target, theta (T) is the angle ofincidence, relative to normal (perpendicular), and d is the distance from the source tothe surface. When the angle of incidence is zero (light is striking the target head on), thecosine of theta is 1.0 and the equation is reduced to the following.

E I

d=

2

The main difficulty in applying the inverse-square law is the trigonometry required todetermine the distance from the light source to the target and the angle of incidence.The candlepower of the luminaire or lamp is usually available from manufacturers'literature.

Figure D-1 Terms in Inverse-Square Law


D-6

Figure D-2 Isofootcandle Diagram

Many outdoor luminaire manufacturers provide isolux or isofootcandle diagrams, suchas shown in Figure D-Error! Reference source not found., which may be used tocalculate illumination levels. These diagrams can be overlaid on a site plan to show theillumination at any point on the site. With multiple luminaires, diagrams are laid ontop of each other. The isofootcandle diagrams are for a specific luminaire mountingheight. If the luminaire is mounted at a different height, all the values on the chart aremultiplied by appropriate correction factors, also provided by the manufacturer. Anadvantage of using isofootcandle charts is that they account for the candlepowerdistribution of the luminaire in all directions.

Vertical illuminance calculations are very useful in determining the illuminance ofupright objects, such as pedestrians, signs, or building entrances. One common use forthis calculation is determining the illuminance necessary for a parking lot closed-circuittelevision security system. The vertical calculation is essentially the same as for the


D-7

horizontal plane except that the process of determining the angle of incidence and thedistance (d) is more complicated.

The inverse-square law works directly for point sources of illumination. It may also beused with linear sources or with area sources, but these calculations are somewhatmore complex, as they require a calculation of exitance. For further information onlinear source or area calculations, consult the IES Lighting Handbook.

E-1

E MEASURING ILLUMINATION LEVELS

This appendix explains the process of making illumination measurements in spaces andaddresses some of the important issues. The purpose of illumination measurements isto determine the average illumination of audited spaces so that it can be compared toIESNA recommendations. If illumination levels are too high, then there may beopportunities for delamping. If illumination levels are too low, then other correctiveactions should be taken.

The actual measurement of illumination levels can be quite accurate. The lumenmethod of estimation is rapid and fairly accurate, usually to within 15–20%, but cannotapproach the accuracy of careful field measurements. Measurements, however, aremore complicated, as discussed below.

As-Is Measurements vs. Initial Lumen Measurements

In lighting retrofit audits, most illumination measurements are “as-is,” which meansthat measurements are taken for the existing condition of the lamps and luminaires.While it is very easy to measure as-is illumination levels, if the luminaires areespecially dirty and/or the lamps are beyond their rated life, measurements will be toolow and comparisons against recommended illumination levels will be invalid. Anexperienced auditor can make adjustments for especially dirty luminaires and/orlamps that are beyond their life.

When the budget permits, a more accurate measurement method is to clean and relampluminaires in sample spaces before taking measurements. Measuring illumination afterthe system is cleaned and relamped, provides a more consistent basis. Anotheradvantage is that after the retrofit, measurements can be again made (with clean andrelamped luminaires) to provide a consistent comparison. It is also easier to assesslighting quality and aesthetics. In cases where the proposed retrofit involves more thansimply replacing selected components such as ballasts, the comparison also allows forthe examination of the installation's workmanship, appearance, and ease ofmaintenance.

If the room is small, all of the luminaires should be cleaned and relamped; in a largerspace, at least six luminaires nearest the measuring reference point should be cleanedand relamped. The luminaires should be thoroughly cleaned on all interior reflectivesurfaces; the diffuser should also be cleaned, or replaced if it is in poor condition. After

Measuring Illumination Levels

E-2

new lamps are installed, they should be "burned in" a minimum of 100 hours forfluorescent lamps and 20 hours for incandescent lamps. This will stabilize output.

When measurements are made for clean and relamped luminaires, the measurementdoes not represent maintained illuminance as defined by IESNA. A light lumendepreciation (LLD) factor should be determined as described in Appendix D and thisfactor should be multiplied times the measured illuminance. Only then can themeasured illuminance be compared to IESNA recommended illuminance levels.

Photometers and Calibration

The accuracy of illumination measurements can be no greater than the accuracy of thephotometer you are using. Some instruments may give lower readings when theirbatteries are weak; make sure the batteries are fresh before taking measurements.

All photometers used for field measurements should be cosine and color corrected sothat their sensitivity mimics that of the human eye. The instrument should also berecently calibrated against a photometer that is known to be accurate or verified by acalibration laboratory. Check with universities, utility lighting laboratories, museums,or testing laboratories in your area.

If you have access to a highly accurate photometer, you can calibrate your photometerby taking a series of parallel measurements with both instruments. Your readingsshould include a range of illumination levels ranging from 5 to 200 or morefootcandles. Multiple measurements should be taken in the moderate illuminationrange (30 to 70 footcandles) which is the area of interest for most field measurements.Test readings should be taken with the meters side by side and the light sources inrealistic positions.

Photometers are calibrated with incandescent calibration standards. When measuringillumination from other sources, use correction factors supplied by the manufacturer.

When you have comparative measurements, you should make a graph and plot theresults. It is recommended that you plot the readings from the accurate photometer onthe horizontal axis and the results of your photometer on the vertical access. Yourgraph would look something like Figure E-1.


E-3

Figure E-1 Photometer Calibration

If readings from your photometer exactly match those of the accurate or referencephotometer, then all pairs of measurements will fall along a straight line on thediagonal. However, in most cases, readings from your photometer will be consistentlyhigher or lower than the reference photometer. When this is the case, you should fit aline through the points and calculate its slope. The slope of the line is a correction factorthat should be applied to readings from your photometer. That is, use a factor that willmake the field photometer readings equal the reference photometer readings.

Measurement Procedures

In retrofit situations, the average illumination is less important than the actualillumination at the work surface where a given visual task will occur. Therefore,measurements should be taken at typical visual task locations.

Before taking measurements, the temperature in the space should be stabilized at itsusual level and the lamps should be operated for at least one hour. A selenium detectorshould be exposed to ambient light for 15 minutes to compensate for cell fatigue. The


E-4

performance of fluorescent systems is very sensitive to temperature variation. Inaddition the meter should be turned on for at least 15 minutes. When takingmeasurements, the surveyor should take care not to stand so close to the meter that heor she blocks available light from reaching the meter. Also be careful of light reflectedby clothing. Some photometers are equipped with a detachable sensor that allows theuser to remain close to the meter without shadowing the sensor.

Measurements in Daylighted Areas

When measuring illumination levels in spaces that have windows or skylights, the goalis to measure separately the light contributions from the electric lights and thedaylighting source. The following steps are recommended:

1. If the space has blinds, close them as tightly as possible, turn on the lights, andmeasure the illuminance. This reading should represent the light contribution fromelectric lighting.

2. Next open the blinds, turn off the lights, and measure the illumination. This readingshould represent the daylighting contribution.

3. Finally, leave the blinds open, turn on the lights, and measure the illumination. Thisreading is the total contribution of electric lights and daylighting. This illuminationshould be equal to the sum of the illumination measured in steps 1 and 2.

If the space has no blinds, a measurement of total light can be taken, followedimmediately by another measurement with the lights turned off. Subtracting the secondmeasurement from the first will give the contribution from the electric lights. Thisapproach is usually required for spaces with skylights since skylights rarely haveblinds or any other type of shading device. The method may yield poor accuracy, sincea change in the electric light contribution may be small compared to the totalilluminance.

Any time measurements are taken in daylighted areas with the blinds open, you shouldbe careful to record the sky conditions. Daylight illumination can vary considerablydepending on overcast conditions, time of day and season of the year. If you are onlyinterested in the contribution from electric lights, consider making the measurements atnight or the late afternoon in winters when the sun is down. Careful measurements indaylighted areas can be used to identify spaces that are good candidates for daylightdimming systems.

Task Lighting

Task lighting generally uses low-wattage luminaires to direct light to the task area. Iftask lighting is already used in the test space, illuminance can be measured both withand without the general lighting contribution. Task lighting alone often provides


E-5

sufficient illumination for the task, allowing ambient lighting to be reduced. If thespace has no task lighting, it should be considered as a possible retrofit measure,because it may allow significant energy-saving reductions in the general lightingsystem. Modern task lighting often makes use of compact fluorescent lamps tomaximize energy savings.

F-1

F CALCULATING COST-EFFECTIVENESS

Introduction

Once you have identified lighting retrofit opportunities and estimated the annualenergy savings, maintenance costs, and construction costs, you must then decide if thelighting retrofit is cost-effective. In some cases, you may want to consider more thanone design alternative, in which case you will want to know which of the alternatives isthe most cost-effective. This appendix provides the technical information you will needto make these assessments.

Payback Period

The most common measure of economic performance is the payback period—theperiod of time it takes for the savings to equal the initial investment. Payback period isbased on the construction cost difference between two competing lighting systems andthe resulting savings due to the more efficient system. As a result, it can only be used tocompare two competing alternatives. If multiple alternatives are to be evaluated, theymust all be compared to a single base case.

While easy to understand, payback period is inadequate in comparing many designalternatives, in particular systems with different lives or maintenance costs. Considerfor instance two retrofit options: one with a cost of $10,000 and annual savings of $2,000per year and a second with a cost of $5,000 and annual savings of $1,000 per year. Bothhave a payback period of 5 years, but which is the better investment? The inadequaciesof payback period are further exposed if the two retrofit options have different livesand varying maintenance or replacement costs. While the payback calculation can beadjusted to consider utility rebates and annualized maintenance costs, more detailedeconomic analysis based on net present value or internal rate of return is recommendedfor more complex cases.

Net Present Value (Life-Cycle Cost)

Net present value is the sum of the initial costs and all future benefits and costs over thelife of the system, discounted to present value. Benefits are generally assigned apositive value while costs are assigned a negative value. In comparing alternatives, theone with the highest net present value is the best investment. Net present value can be

Calculating Cost-Effectiveness

F-2

used to compare several different systems and is especially useful in comparing designalternatives with different or irregular cash flows, or design alternatives with differentlives.

Expenses or costs that occur in the future have a smaller value in current dollars. Therate at which future expenses or costs are discounted is the discount rate. It is thepercent reduction in future benefits or costs for each year in the future. Anunderstanding of discount rate is necessary in order to understand other measures ofeconomic performance such as net present value, annualized cost, benefit to cost ratio,or internal rate of return.

The discount rate can be "real" or "nominal." The real discount rate is the rate at whichfuture benefits or costs are discounted without consideration for inflation. If futureexpenses and costs are quantified in current dollars, a real discount rate is used. It isgenerally easier to quantify future benefits and costs in current dollars, so a realdiscount rate is commonly used in economic analysis. If future expenses and costs arequantified in inflated dollars, then a nominal discount rate should be used. Thenominal discount rate is the real discount rate plus the inflation rate.

The discount rate is the rate of return that an investor typically makes or expects tomake from other investment opportunities with a similar risk. It also indicates whetheran investor has a short-term or long-term perspective. Investors with a short-termperspective generally have a higher discount rate, while investors with a long-termperspective have a lower discount rate. Risk must also be considered in selecting adiscount rate. Since investments in efficient lighting involve little risk, the discount rateshould be based on consideration of other low-risk investments such as governmentsecurities. Using this logic, if the return on investment for government securities is 8%and the general inflation rate is 5%, then an appropriate real discount rate is 3%.

A discount rate may be used to calculate the present value of future costs. The presentvalue of a cost occurring "n" years in the future with a discount rate of "i" is obtained bymultiplying the cost by a present worth factor. The present worth factor or PWF isgiven by the following equation:

( )PWF

11 i n

=+

Tables of present worth factors may be calculated for a variety of discount rates andyears into the future so that the above equation does not have to be evaluated for everycase. Such a table is included as Table F-1. To calculate the present worth of a futurebenefit or cost, select a value from the table based on the discount rate and the numberof years into the future and multiply the selected value times the future cost or benefit.Keep in mind that if the future cost or benefit is quantified in today's dollars, a realdiscount rate should be used. Otherwise, a nominal discount rate should be used.


F-3

Energy costs or savings (like maintenance costs) also occur in the future and may needto be discounted to present value. The values in Table F-1 could be used to discounteach annual energy cost, but there are easier ways. If a cost or benefit occurs as a timeseries, that is, the same cost or benefit occurs each year for some period of time, thenthe net present value of this series of costs or benefits can be determined by multiplyingthe first year cost times a series present worth factor (SPWF).

Table F-1Present Worth Factors

Discount Rate

Number ofYears

1% 2% 3% 4% 5% 6% 7% 8% 10% 12% 14% 16% 18%

1 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.93 0.91 0.89 0.88 0.86 0.85

2 0.98 0.96 0.94 0.92 0.91 0.89 0.87 0.86 0.83 0.80 0.77 0.74 0.72

3 0.97 0.94 0.92 0.89 0.86 0.84 0.82 0.79 0.75 0.71 0.67 0.64 0.61

4 0.96 0.92 0.89 0.85 0.82 0.79 0.76 0.74 0.68 0.64 0.59 0.55 0.52

5 0.95 0.91 0.86 0.82 0.78 0.75 0.71 0.68 0.62 0.57 0.52 0.48 0.44

6 0.94 0.89 0.84 0.79 0.75 0.70 0.67 0.63 0.56 0.51 0.46 0.41 0.37

7 0.93 0.87 0.81 0.76 0.71 0.67 0.62 0.58 0.51 0.45 0.40 0.35 0.31

8 0.92 0.85 0.79 0.73 0.68 0.63 0.58 0.54 0.47 0.40 0.35 0.31 0.27

9 0.91 0.84 0.77 0.70 0.64 0.59 0.54 0.50 0.42 0.36 0.31 0.26 0.23

10 0.91 0.82 0.74 0.68 0.61 0.56 0.51 0.46 0.39 0.32 0.27 0.23 0.19

11 0.90 0.80 0.72 0.65 0.58 0.53 0.48 0.43 0.35 0.29 0.24 0.20 0.16

12 0.89 0.79 0.70 0.62 0.56 0.50 0.44 0.40 0.32 0.26 0.21 0.17 0.14

13 0.88 0.77 0.68 0.60 0.53 0.47 0.41 0.37 0.29 0.23 0.18 0.15 0.12

14 0.87 0.76 0.66 0.58 0.51 0.44 0.39 0.34 0.26 0.20 0.16 0.13 0.10

15 0.86 0.74 0.64 0.56 0.48 0.42 0.36 0.32 0.24 0.18 0.14 0.11 0.08

16 0.85 0.73 0.62 0.53 0.46 0.39 0.34 0.29 0.22 0.16 0.12 0.09 0.07

17 0.84 0.71 0.61 0.51 0.44 0.37 0.32 0.27 0.20 0.15 0.11 0.08 0.06

18 0.84 0.70 0.59 0.49 0.42 0.35 0.30 0.25 0.18 0.13 0.09 0.07 0.05

19 0.83 0.69 0.57 0.47 0.40 0.33 0.28 0.23 0.16 0.12 0.08 0.06 0.04

20 0.82 0.67 0.55 0.46 0.38 0.31 0.26 0.21 0.15 0.10 0.07 0.05 0.04

21 0.81 0.66 0.54 0.44 0.36 0.29 0.24 0.20 0.14 0.09 0.06 0.04 0.03

22 0.80 0.65 0.52 0.42 0.34 0.28 0.23 0.18 0.12 0.08 0.06 0.04 0.03

23 0.80 0.63 0.51 0.41 0.33 0.26 0.21 0.17 0.11 0.07 0.05 0.03 0.02

24 0.79 0.62 0.49 0.39 0.31 0.25 0.20 0.16 0.10 0.07 0.04 0.03 0.02

25 0.78 0.61 0.48 0.38 0.30 0.23 0.18 0.15 0.09 0.06 0.04 0.02 0.02

26 0.77 0.60 0.46 0.36 0.28 0.22 0.17 0.14 0.08 0.05 0.03 0.02 0.01

27 0.76 0.59 0.45 0.35 0.27 0.21 0.16 0.13 0.08 0.05 0.03 0.02 0.01

28 0.76 0.57 0.44 0.33 0.26 0.20 0.15 0.12 0.07 0.04 0.03 0.02 0.01

29 0.75 0.56 0.42 0.32 0.24 0.18 0.14 0.11 0.06 0.04 0.02 0.01 0.01

30 0.74 0.55 0.41 0.31 0.23 0.17 0.13 0.10 0.06 0.03 0.02 0.01 0.01


F-4

Table F-2Series Present Worth Factors

Discount Rate

Number ofYears

1% 2% 3% 4% 5% 6% 7% 8% 10% 12% 14% 16% 18%

1 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.93 0.91 0.89 0.88 0.86 0.85

2 1.97 1.94 1.91 1.89 1.86 1.83 1.81 1.78 1.74 1.69 1.65 1.61 1.57

3 2.94 2.88 2.83 2.78 2.72 2.67 2.62 2.58 2.49 2.40 2.32 2.25 2.17

4 3.90 3.81 3.72 3.63 3.55 3.47 3.39 3.31 3.17 3.04 2.91 2.80 2.69

5 4.85 4.71 4.58 4.45 4.33 4.21 4.10 3.99 3.79 3.60 3.43 3.27 3.13

6 5.80 5.60 5.42 5.24 5.08 4.92 4.77 4.62 4.36 4.11 3.89 3.68 3.50

7 6.73 6.47 6.23 6.00 5.79 5.58 5.39 5.21 4.87 4.56 4.29 4.04 3.81

8 7.65 7.33 7.02 6.73 6.46 6.21 5.97 5.75 5.33 4.97 4.64 4.34 4.08

9 8.57 8.16 7.79 7.44 7.11 6.80 6.52 6.25 5.76 5.33 4.95 4.61 4.30

10 9.47 8.98 8.53 8.11 7.72 7.36 7.02 6.71 6.14 5.65 5.22 4.83 4.49

11 10.37 9.79 9.25 8.76 8.31 7.89 7.50 7.14 6.50 5.94 5.45 5.03 4.66

12 11.26 10.58 9.95 9.39 8.86 8.38 7.94 7.54 6.81 6.19 5.66 5.20 4.79

13 12.13 11.35 10.63 9.99 9.39 8.85 8.36 7.90 7.10 6.42 5.84 5.34 4.91

14 13.00 12.11 11.30 10.56 9.90 9.29 8.75 8.24 7.37 6.63 6.00 5.47 5.01

15 13.87 12.85 11.94 11.12 10.38 9.71 9.11 8.56 7.61 6.81 6.14 5.58 5.09

16 14.72 13.58 12.56 11.65 10.84 10.11 9.45 8.85 7.82 6.97 6.27 5.67 5.16

17 15.56 14.29 13.17 12.17 11.27 10.48 9.76 9.12 8.02 7.12 6.37 5.75 5.22

18 16.40 14.99 13.75 12.66 11.69 10.83 10.06 9.37 8.20 7.25 6.47 5.82 5.27

19 17.23 15.68 14.32 13.13 12.09 11.16 10.34 9.60 8.36 7.37 6.55 5.88 5.32

20 18.05 16.35 14.88 13.59 12.46 11.47 10.59 9.82 8.51 7.47 6.62 5.93 5.35

21 18.86 17.01 15.42 14.03 12.82 11.76 10.84 10.02 8.65 7.56 6.69 5.97 5.38

22 19.66 17.66 15.94 14.45 13.16 12.04 11.06 10.20 8.77 7.64 6.74 6.01 5.41

23 20.46 18.29 16.44 14.86 13.49 12.30 11.27 10.37 8.88 7.72 6.79 6.04 5.43

24 21.24 18.91 16.94 15.25 13.80 12.55 11.47 10.53 8.98 7.78 6.84 6.07 5.45

25 22.02 19.52 17.41 15.62 14.09 12.78 11.65 10.67 9.08 7.84 6.87 6.10 5.47

26 22.80 20.12 17.88 15.98 14.38 13.00 11.83 10.81 9.16 7.90 6.91 6.12 5.48

27 23.56 20.71 18.33 16.33 14.64 13.21 11.99 10.94 9.24 7.94 6.94 6.14 5.49

28 24.32 21.28 18.76 16.66 14.90 13.41 12.14 11.05 9.31 7.98 6.96 6.15 5.50

29 25.07 21.84 19.19 16.98 15.14 13.59 12.28 11.16 9.37 8.02 6.98 6.17 5.51

30 25.81 22.40 19.60 17.29 15.37 13.76 12.41 11.26 9.43 8.06 7.00 6.18 5.52


F-5

The SPWF for "n" years or periods and a discount rate of "i," can be calculated with thefollowing equation.

( )( )

SPWF1 i 1

i 1 i

n

n= + −+

Table F-2 contains precalculated series present worth factors for a variety of discountrates and years into the future. To calculate the net present value of a time series offuture benefits or costs, select a value from the table based on the discount rate and thenumber of years into the future and multiply the selected value times the first year costor benefit.

Benefit-to-Cost Ratio

Benefit-to-cost ratio is another way of evaluating investments. This is the ratio of the netpresent value of all benefits to the net present value of all costs. All investments with aratio greater than one may be considered cost-effective. In comparing multipleinvestment alternatives, all would have to be compared to a base case. The one with thehighest benefit-to-cost ratio is the best investment opportunity.

Internal Rate of Return

The internal rate of return (IRR) is the discount rate at which the present value of futurebenefits in energy savings and maintenance cost savings is equal to the initial costpremium. Put another way, it is the return on investment with all future costs andsavings considered. The IRR of an investment can be viewed as the amount of annualinterest (in percent) paid on the investment over the life of the project. The internal rateof return must be calculated through a process of iteration, but many spreadsheetprograms have built in functions that are capable of calculating the IRR.

Annualized Cost

Annualized cost is a useful method of comparing lighting alternatives. The initial costsand periodic maintenance costs are converted to an equivalent annual payment andadded to the annual energy costs. The design alternative with the lowest annual cost isthe one that is most cost-effective. Annualized cost is especially useful when initialcosts are financed. Like IRR, annualized cost can be calculated with spreadsheetprograms.


F-6

Other Issues

Inflation and Energy Cost Escalation Rates

The price of all goods and services increases over time at the general inflation rate. Aslong as all future costs increase at the same rate, inflation may be ignored in evaluatingthe economic performance of investments in energy efficiency. With this approach,commonly used in economic analysis, all future costs are quantified in current dollarsand discounted at a real discount rate.

If there is reason to believe that energy costs will increase at a rate different from thegeneral inflation rate, each future energy cost should be quantified in inflated dollarsand discounted to present value using a nominal discount rate.

Tax Considerations

Investments in energy efficiency have tax implications that need to be considered indetailed economic analysis. Energy costs are an expense; so when energy costs arereduced, taxable income is increased and potentially some of the energy savings arepaid to the government as additional taxes. On the other hand, investments in energyefficiency can be depreciated over the life of the equipment, offering a tax benefit. Formany businesses, these offset each other, but they must be considered on a case-by-casebasis.

G-1

G POWER QUALITY

Among the most important topics for the lighting retrofitter is power quality. Allelectric loads in a building affect the building's power quality. However, with agrowing percentage of loads exhibiting nonlinear current consumption, utilities andusers have expressed concerns over the power quality delivered throughout a building.This is particularly true for sensitive electronic loads, such as computers andperipherals.

Power quality issues affect lighting retrofitters in at least three ways. First, manyengineers and most utility incentive programs require that lighting retrofit equipmentmeet minimum standards for power factor and harmonic distortion. Second, advancedlighting components such as electronic ballasts and control equipment can be verysensitive to incoming variations in voltage. Third, electronic ballasts can affect othersensitive equipment which impedes use of new ballasts.

Power quality concerns that must be included when evaluating lighting retrofit optionsinclude harmonic distortion, power factor, and voltage fluctuations. Samplespecifications contained herein address these issues and are intended to promote theuse of equipment that meets or exceeds utility standards for power factor and harmonicdistortion.

Supply Voltage

The most basic power quality issue concerns a building's supply voltage. Fluctuationsin supply voltage occur in four different ways, all of which affect electrical components,as well as overall building power quality.

Voltage Regulation

Variance between supply voltage and intended design voltage, caused by poor voltageregulation, is a primary concern for manufacturers and specifiers of lighting and otherelectrical components. Most modern electrical components are designed to operate witha very specific supply voltage. When supply voltage varies from intended designvoltage by 5% or more, adverse effects may result. These include short incandescentlamp life, overheating of motors and transformers, and other damage to electricalcomponents.

Power Quality

G-2

Voltage Transients

Voltage transients, commonly known as "spikes," are brief periods of extremely highvoltage. Transients may be caused by lightning strikes, high-voltage line switching bythe utility, or other factors. Transients are a primary cause of electronic equipmentfailure, as a voltage spike 10 to 20 times higher than the intended design voltage makesquick work of electronic components. Lighting components that suffer from voltagetransients include electronic ballasts, dimmers, and other devices that use solid-statecomponents.

Voltage Surges and Sags

Voltage fluctuations in the form of surges and sags, are caused by utility companyproblems, or in some cases, the operation of large equipment in buildings. Surges andsags generally last a few seconds but can significantly affect the performance ofelectrical equipment.

Voltage Interruption

Interruptions in supply voltage due to brownouts, dropouts, and blackouts are causedby problems with electric power generation, transmission and/or distribution systems.Brownouts can cause serious damage to equipment and should be cause for mostelectric equipment to be turned off. Dropouts are short-term blackouts that can beespecially damaging if frequent attempts to restore power produce voltage transients.

Fluctuations in building supply voltage have been a concern ever since the advent ofthe mainframe computer. As such, since the 1960s it has been common practice todesign power isolation conditioners and uninterruptable power supplies (UPS) formainframe computers. UPS systems are also popular peripherals for critical computersystems such as network file servers, where they can prevent damage and data loss dueto sags, dropouts, and brownouts. For personal desktop-type computers, surge andtransient suppressers and compact unit UPS systems are commonly used to guardagainst voltage fluctuation problems.

A paradoxical feature of UPS systems, conditioners, suppressers, and the devices theyare designed to protect is that these components are notorious for having relativelypoor power factor along with correspondingly high levels of harmonic distortion. Assuch, they actually contribute to a degradation of overall building power quality, evenas they guard against its more debilitating effects to the individual load.

Power Quality

G-3

Power Factor

A large percentage of the electrical load in modern buildings is accounted for byinductive devices, such as motors, transformers, and fluorescent lighting systems. Inaddition to the working power (kW) required to perform the actual electrical work,inductive loads consume reactive power, measured in kilovolt-amperes-reactive(kVAR). Reactive power sustains the electromagnetic field that nonlinear electricalloads require. As such, although kVAR loads perform no specific work function, theycombine with kW to determine the amount of apparent power (kVA) that the utilitymust deliver to the facility.

Power factor refers to the ratio of working power (kW) consumed by an electricaldevice to the apparent power (kVA) delivered to it. Electrical loads that have relativelylow power factors are inefficient in that they draw excessive current in proportion tothe working power they require. For example, a 20-watt compact fluorescent lampballast with a low power factor of .40 actually requires 50 VA of current to energize thedevice. Thus, the electrical utility must supply more than twice the current than wouldbe required for a more efficient component. In comparison, a high power factor (HPF)ballast with a power factor of 0.90 or better for the same lamp would require only about22 VA to accomplish the same task.

If a significant proportion of a building's electrical requirement is represented by lowpower factor devices, the electrical distribution system must be oversized to handle theresultant larger currents and avoid overloading and overheating components.Similarly, branch circuiting and overcurrent protection must be sized accordingly. In aworst case scenario, excessively low building power factor can cause voltage drop orsag, causing sensitive electrical components to fail.

With lighting equipment, power factor is a potential concern for all discharge lamp-ballast systems, such as fluorescent and HID components. Fortunately, most modernfluorescent and HID lighting components are now available with HPF ballasts. HPFballasts have power factors of 0.90 or better. With the 277V components common incommercial applications, HPF ballasts are the rule, rather than the exception.Nevertheless, many 120V lighting components are equipped with "normal" powerfactor (NPF, PF # 0.50) ballasts as standard equipment. This is particularly commonwith compact and low-wattage HPS fluorescent luminaires, where, in many cases, HPFballasts are available only as an added-cost option.

Harmonic Distortion

Harmonic distortion refers to harmonic frequencies that are higher multiples of thefundamental frequency (60 Hz in 120V AC systems). These frequencies superimposethemselves on the purely sinusoidal wave form, resulting in what some plant engineers

Power Quality

G-4

refer to as "dirty power." Harmonic distortion is usually associated with an increase inthe use of nonlinear loads. A nonlinear load refers to any electrical device whosevoltage is not proportional to its current. Such devices consume current in bursts ratherthan constantly. This is a characteristic of electrical components that contain electronicpower converters that employ solid state switching. Examples include adjustable speeddrives, UPS systems, and personal computers. In addition, arcing devices, such as arcfurnaces, arc welders and fluorescent lamps, draw current in a nonlinear fashion.Unlike other types of power quality problems such as surges and spikes, harmonicdistortion is not a short-term phenomenon, and it cannot be controlled withsuppressing devices.

There are two types of harmonic distortion:

x Current harmonic distortion (CHD) is produced by any nonlinear electrical device, asdescribed above, whose voltage is not proportional to its current.

x Voltage harmonic distortion (VHD) is caused by CHD. The distorted current wavecauses a distorted voltage drop in the building system services, primarily throughlosses in distribution transformers and ordinary wiring. The resulting systemvoltage is thus distorted, with effects noticeable throughout the entirety of thebuilding.

IEEE Standard 519 permits up to 5% voltage harmonic distortion in a building. Tocause this, current harmonic distortion of at least 25% of the same type and at full ratedload must be present in the building. Since different harmonic distortion percentagesdo not add, and in fact, sometimes can cancel one another, serious voltage harmonicdistortion problems are seldom encountered. But it is the growing likelihood of thispotential condition that has utilities and engineers worried. Harmonic distortion isassociated with several well-known problems:

1. Current harmonic distortion can cause neutral overcurrents in three phase systems.This can occur in both home-run circuits and panelboard neutrals.

2. Current harmonic distortion can cause distribution transformer overheating. Thesmaller the transformer, the greater the potential problem.

3. Voltage harmonic distortion can cause problems with electronic loads. Mostnotably, it can introduce floating and possibly even hazardous voltages on theneutral conductor.

Ordinary transformers should be derated as much as 50% if the load has high harmoniccontent. Transformers can be "k-rated" to match the expected harmonic load at fullcapacity, but most are not. In general, voltage harmonic distortion, neutralovercurrents, and transformer overheating are very likely to occur in ordinarybuildings' 120/208 volt systems. It is here where the growth in computers andperipherals has been greatest and where the power systems were generally notdesigned for the load. Worse, the harmonic distortion of computer and peripheral loads

Power Quality

G-5

tends to be the "current gulping" wave distortion common among most electronicdevices, all about the same harmonic content and over 100% current harmonicdistortion. In these buildings, the 277/480 volt power systems feeding fluorescent andHID systems generally have very little harmonic distortion.

H-1

H LIGHTING SURVEY FORMS

Suggested Data Structure

A great deal of information will be collected during the data collection phase of theproject. It is essential that data be collected in an orderly manner. To minimize errorsand speed the collection process. This appendix presents a suggested structure fororganizing the data. The structure is diagrammed in Figure H-1. Each element in thisdiagram is a table of information to be collected. The lines connecting the tables showrelationships. For instance, each record in the Spaces table includes the ID number ofthe project that the space belongs to. Most of the relationships are many-to-one, whichmeans for instance, that a project can have more than one space. Many-to-onerelationships are indicated with the notations “1” and “f.“ Other relations are one-to-one. For instance the relationship between Space Groups and Spaces is one-to-one. Thismeans that there is one and only one record in the Space Groups table for each recordin the Spaces table. The one-to-one relationship is indicated with the notations “1” and“1”. The recommended data structure is consistent with LightPAD 2.0.

Project

At the root of the data tree is the project itself. A great deal of general informationshould be collected about the project, including the name, address, phone number, etc.of the utility customer, the building, the utility representative, and the lighting retrofitauditor. The project data might also include the date of initial contact, when the auditwas started, when it was finished, etc. These dates may be useful in tracking the statusof multiple projects. An input form that you can copy and use in the field is providedas Figure H-2. In addition to completing the fields listed above, the auditor shouldmake general notes and sketches as necessary to document the building.

Billing History

Utility records should be collected for the project. For each month or billing period, thepeak demand (kW), electricity use (kWh), and monthly bill should be collected. Datashould be collected for a minimum period of one year, but additional data should becollected if available. The utility data will be useful in determining the average orvirtual electricity rate which includes consideration of time-of-use and demandcharges. Data may also be useful in calibrating analysis models and in determining

Lighting Survey Forms

H-2

hours of lighting operation. Figure H-3 may be used as a data input form for collectingbilling history. If a flat utility rate is used, it is only necessary to fill in the “Total”columns.

Figure H-1 Suggested Data Structure

Fixture Schedule

Each building will usually have a limited number of lighting fixture types. The fixtureschedule is a listing of all the unique fixtures. Preparing a fixture schedule will savetime in doing the space-by-space audit since it will only be necessary to indicate the IDof the fixture when taking down information about a space. All information that isspecific to the fixture will be contained in the fixture schedule. Information shouldinclude: ID (must be unique), name, input watts, housing type, lamp types, ballasttype(s), number of lamps, number of ballasts, and perhaps coefficient of utilization(CU) tables. You should also photograph each unique lighting fixture. Clearly markeach photograph and include a photo reference on the schedule for each. The latterinformation is necessary if lighting level calculations are to be performed. Figure H-4 isa data input form that may be used for constructing the fixture schedule.


H-3

Figure H-2 Data Input Form—Project


H-4

Figure H-3 Data Input Form—Billing History

Figure H-4 Data Input Form—Fixture Schedule

Spaces

Collecting information at the space level is the most time consuming task. This is why itis important to identify similar spaces when possible and only audit a sample of thesimilar spaces. Note that similar spaces must have not only the same lighting fixtures,but also the same operating schedule. Figure H-5 shows the information to collect foreach space. Data needed only if lighting level calculations are to be performed for thespace are indicated with the symbol “*”.

The spaces form includes a table for entering information about lighting systems orequipment in the space. The space equipment table identifies the quantity and type oflighting equipment located in each space. Each record in the table must have thenumber of fixtures, the height of the fixtures above the floor, a pointer to the fixtureschedule, a pointer to a schedule of lighting operation or the full-time equivalentannual lighting hours, a coefficient of utilization for the space, the luminaire dirtdepreciation (which can vary from space to space) and the contribution that the


H-5

luminaire makes to the general illumination of the space (used in light levelcalculations).

Note that schedules of operation are associated with lighting equipment, not with thespace in which they are located. This enables different schedules of operation fordifferent groups of fixtures in a single space. This may be important in assessing thebenefits of daylighting controls, occupant sensors, and/or other lighting controltechnologies.

Figure H-5 Data Input Form—Space Data

I-1

I LIGHTING EDUCATION AND LABORATORY

FACILITIES

Utility-operated Centers

Lighting Design Lab400 E. Pine StSeattle, WAPhone (206) 325-9711

Website: http://www.northwestlighting.com

The Lighting Design Lab is a multipurpose lightingdemonstration, education, and research facility locatednear downtown Seattle. Regular educational programsand classes are offered in all aspects of lighting includingIES classes and special seminars. The Lab’s mockup spaceequipped with movable ceilings is available for public andprivate projects as is the facility’s artificial sky. Anextensive library including computers and technicalassistance is available. Publishes the Lighting Design LabNews quarterly.

Portland General Electric EnergyPGE Lighting Lab410 Southwest OakPortland, OR 97204Phone (503) 464-7501e-mail: lark [email protected]

The Lighting Lab is a lighting-only educational anddemonstration facility located in downtown Portland.IESNA classes and other special programs are offered. Thefacility’s primary asset is a fully equipped lightingeducation and demonstration room that is available forpublic or private use on a fee basis.

Pacific Gas & Electric EnergyCenter851 Howard StreetSan Francisco, CA 94103Phone (415) 973-7268e-mail: [email protected]:http://www.pge.com/pec

The Energy Center is a fully-equipped facility designed foreducation, demonstration and customer education,mockup, and research in all facets of building energyefficiency. Extensive programs including IESNA classesare available. Mockup facilities include two bays withmoving ceilings, a model-making area, a heliodon, anddaylight modeling and testing areas. Periodic displayprograms oriented around themes such as retrofitting areon display. An extensive library complete with computerswith demonstration versions of modern software isavailable.

Lighting Education and Laboratory Facilities

I-2

Southern California EdisonCustomer Technology ApplicationCenter (CTAC)6090 North Irwindale AvenueIrwindale, CA 91702Phone (818) 812-7380Website: http://www.edisonx.com

Within CTAC’s overall energy technologies facility, acomplete lighting design and technology center offersequipment demonstrations, application classes, andconsumer advice. Special classes and programs areproduced for industry groups and organizations asneeded.

Energy Resource CenterSouthern California Gas Co.9240 E. Firestone Blvd.Downey, CA 90240Phone (800) 427-6584Website:http://www.socalgas.com/erc

A demonstration, education, and conference center, theERC provides programs in gas and electric technologies.

Sacramento Municipal UtilityDistrict (SMUD)Energy Technology Center6301 S Street MS A226Sacramento, CA 95817(916) 732-6738Website:http://www.smud.org/etc

Facility to showcase and demonstrate a wide range ofelectric energy efficiency technologies within a state of theart office complex. Complete lighting classroom andconference facilities. Lighting library and computereducation facility.

Tampa Electric Energy Center(ETRC)3650 Spectrum Blvd.Tampa, FL 33612Phone (813) 202-1770

Website:http://www.teco.net/ETRC

Tampa Electric Company’s ETRC displays high efficiencytechnologies including lighting, foodservice, and anadvanced technology center. It specializes in education,training, information, consulting services and evaluationservices.

Carolina Power & Light SolutionsCenter7001 Pinecrest Rd.Raleigh, NC 27613Phone (888) 800-7599

Website:http://wwwcplc.com/solcenter

The CP&L Solutions Center demonstrates innovative andenergy-efficient technologies, including lighting powerquality and HVAC, to CP&L customers and associates.


I-3

Other utilities may have centers not listed. Contact your local utility for more information.


I-4

Lamp Company Centers

LIGHTPOINTOsram Sylvania, Inc.100 Endicott St.Danvers, MA 01923(508) 777-1900

State-of-the-art education facility with demonstration room,classroom, and facility for teaching vision and qualityprinciples. Demonstration area features company’s lampproducts.

General Electric CompanyThe Lighting InstituteNela Park, Cleveland, OH 44112(800) 255-1200

Specification CentersNew York, NYChicago, ILAtlanta, GALos Angeles, CA

State-of-the-art education facility with demonstrationrooms, classroom, and facility for teaching vision anddesign principles. Areas feature company’s lampproducts.

Specification centers feature lighting classrooms offeringfundamental education and product demonstration insupport of regional sales activities.

Philips LightingLighting Center200 Frankilin Square DrivePO Box 6800Somerset, NJ08875-6800(908) 563-3600

State-of-the-art education facility with demonstration room,classroom, and facility for teaching vision and designprinciples. Areas feature company’s lamp products.


I-5

Luminaire Manufacturer Centers

Cooper LightingThe SOURCE400 Busse RaodElk Grove Village, IL 60007(708) 956-8400

A 14,000 ft2 complex with multiple rooms and displaysfeaturing company products. Classes of varying lengthsinclude general education and classes in LUXICON.

Lithonia LightingLithonia Lighting CenterPO Box AConyers, GA 30207(770) 922-9000

A 20,000 ft2 complex with multiple rooms and displaysfeaturing company products. Classes of varying lengthsinclude general education and classes in VISUAL.

Canlyte Inc.Lighting Concept Center160 Pears Ave.Toronto, ONT CA M5R 1T2(416) 960-1400

Demonstration and resource facility. Classes of varyinglengths include general education and classes in GENESYS.

Prescolite Specification Center1251 Doolittle Dr.San Leandro, CA 94577(510) 562-3500

Demonstration and resource facility. Classes of varyinglengths include general education and classes in LITEPRO.

Other manufacturer have facilities. If in question, ask the manufacturer in whose products youhave interest.

© 2002 Electric Power Research Institute (EPRI), Inc.All rightsreserved. Electric Power Research Institute and EPRI are registered service marks of the Electric Power Research Institute, Inc.EPRI. ELECTRIFY THE WORLD is a service mark of the ElectricPower Research Institute, Inc.

Printed on recycled paper in the United States of America

TR-107130R!

EPRI • 3412 Hillview Avenue, Palo Alto, California 94304 • PO Box 10412, Palo Alto, California 94303 • USA800.313.3774 • 650.855.2121 • [email protected] • www.epri.com

About EPRI

EPRI creates science and technology solutions for

the global energy and energy services industry. U.S.

electric utilities established the Electric Power

Research Institute in 1973 as a nonprofit research

consortium for the benefit of utility members, their

customers, and society. Now known simply as EPRI,

the company provides a wide range of innovative

products and services to more than 1000 energy-

related organizations in 40 countries. EPRI’s

multidisciplinary team of scientists and engineers

draws on a worldwide network of technical and

business expertise to help solve today’s toughest

energy and environmental problems.

EPRI. Electrify the World