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Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
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Energy Ene Bg 4
Environmental Building Guidelines for Greater Hyderabad — Ver. 1.2(2010)
The following design guidelines should be considered at the design
and installation stage of all new residential and commercial buildings:
1. Ensure that the illuminance levels on working plane conforms
the level recommended by NBC (BIS 2005) in Table 4 (clauses
4.1.3, 4.1.3.2, 4.3.2 and 4.3.2.1) [Part 8 Building services -
Section 1 lighting and ventilation]
2. Ensure that the uniformity ratio (minimum illuminance
divided by average illuminance levels) of an area, which is
entirely being utilized as work place, should not be less than
0.7 as per recommended in NBC (BIS2005).
3. Select lamps with high Colour rendering index.
4. Do not exceed the LPD (light power density) as
recommended by Energy Conservation Building Code 2007
5. Apply lighting controls as recommended by ECBC 2007
6. Integrate daylight control strategies for perimeter areas with
access to day lighting
7. Retrofit external and common area lighting with efficient
fixtures and apply lighting controls in existing residential
complexes/buildings.
8. All the spaces should use of efficient lighting equipment e.g.
lamps, luminaries and control gears.
An energy efficient lighting design must meet with minimum
illuminance level for specified task as specified by NBC. Illumination
level for specified task should be maintained at all times as
recommended by National building code 2005. The National Building
Code recommends a range of illumination levels for a activity as
circumstances may be significantly different for different interiors
used for the same application or for different conditions for the same kind of activity. Each range consists of three successive steps of
recommended scale of illuminance. For working interiors, the middle
value of each range represents the recommended service illuminance
that should be used. It should be ensured that the required
illumination level is provided by use of efficient lamp and luminaire
combination. Suitable control strategies should be simultaneously
applied to switch off or dim lights during unoccupied or day lit hours.
All these measures ensure efficient lighting.
Design energy efficient lighting in
all new residential and commercial buildings
Checklist
New build
Des
O & M
Con
1. Maintain
recommended
illumination
levels
2. Maintain
uniformity
ratio
3. Maintain
lighting power
4. Apply contols
5. Retrofit
suitably
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
Good lighting aims at illuminating the task effectively and the general surroundings
appropriately.
Good lighting design enhances architecture but energy-efficient lighting design enhances
both the design and the performance of building.
Energy-efficient lighting design focuses on methods and materials that improve both quality
and efficiency of lighting.
A good lighting design should be able to provide desired quantity and quality of light at
minimum energy consumption.
Lighting contributes to significant energy consumption in buildings. In air conditioned
buildings lighting energy consumption may be as high as as 20-25% of total energy
consumed, whereas in non air conditioned buildings, share of lighting energy consumption
may be as high as 60% of its net energy consumption.
Hence it is important to design and operate lighting systems efficiently.
Use of efficient lighting serves the purpose of visibility and safety– Maintaining the ade-
quate lighting level as per the task and use of efficient lamps with provides sufficient light for
performing required task without wasting any energy.
Use of Controls– Reducing the connected load of the lighting system represents partly the
potential for maximizing energy savings. Lighting controls play a major role in reducing en-
ergy consumption by avoiding wastages. There are numerous choices available today from
simple light switches to fully automated systems. Automatic controls switch off or dim the
lights based on the time, occupancy, illumination requirements, or a combination of all three.
Please refer guidance note for more details.
Retrofit– The existing building campuses get advantage of saving in electricity bills by retrofit
options.
Saves operating costs: Energy efficient lighting have minimal incremental cost (sometimes
the cost is lower due to reduction in total number of luminaries and lamps required to pro-
vide requisite illumination) and the payback period is usually within six to eight months
Energy efficient lighting is very cost effective as an ECM (energy conservation measure). The
incremental cost usually gets paid back within a year’s time. A sample study has been en-
closed at the end of the guidance notes.
How is it Beneficial?
1. Detailed listing of connected load for lighting, and details like luminous efficacy (Lumen
Output/wattage) etc. for all the types of lamps should be submitted in following Table 1
format.
2. Calculation of connected load for indoor lighting and energy requirement for the same in the
format given in Table 2.
Submittals
Why is it required?
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
Table 1: Detailed listing of connected load for lighting, and details like luminous Efficacy
(Lumen Output/wattage) etc. for all the types of lamps
Table 2 Calculation of connected load for indoor lighting and energy requirement
List out the control strategies applied to reduce wastage.
Floor Level Room/
Area
Room Dimensions (Length X Width)
Calculated average Lighting (Lux) levels
Recommended lighting levels as per NBC
Code Luminaire
Lamps Ballast Luminaire
wattage
Luminous Efficacy
Make Description Type Make Lumen
output
Wattage Type Make Power
loss
(W)
(Lamp+
Ballast)
Achieved Minimum
recom-
mended
A-1 Philips TBC-22 CFL Phil-
ips
600 10 Elec-
tronic
Phil-
ips
2 12 50 50
An energy efficient approach to design for energy efficient lighting aims to cover the following
aspects.
Illuminance level for specified task
Use of efficient lighting equipment e.g. lamps, luminaries and control gears
Use of appropriate controls.
Explore possibilities of daylight integration
Ensure effective maintenance
Additionally the following parameters are also critical to a good lighting design
Room surface brightness
Glare reduction
Uniform light distribution
Good lamp coloration
Design for specified illumination level as recommended by the National
Building Code 2005
The basic intent in an efficient lighting design to achieve the desired illumination level and light
quality at minimum energy use. For the purpose of achieving the desired objectives, the following
procedure should be followed to ensure efficient lighting
Illumination level for specified task should be maintained at all times as recommended by
National building code 2005.
The National Building Code recommends a range of illumination levels for a activity as
Guidance Notes
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
circumstances may be significantly different for different interiors used for the same application
or for different conditions for the same kind of activity. Each range consists of three successive
steps of recommended scale of illuminance. For working interiors, the middle value of each range
represents the recommended service illuminance that should be used unless one or more of the
factors mentioned below apply.
The higher value of the range should be used when:
Unusually low reflectance or contrasts are present in the task;
Errors are costly to rectify
Visual work is critical
Accuracy or high productivity is of great importance; and
The visual capacity of the worker makes it necessary.
The lower value of the range may be used when:
Reflectance or contrast are unusually high;
Speed and accuracy is not important; and
The task is executed only occasionally.
Where a visual task is required to be carried out through an interior, general illumination level
meeting the recommended value on the working plane is necessary; where the precise height and
location of the task are not known or cannot be easily specified, the recommended value is that
on horizontal 850 mm above floor level.
Where the task is localised, the recommended value is that for the task only; it need not, and
sometimes should not, be the general level of illumination used throughout the interior. Some
processes, such as industrial inspection process, call for lighting of specialized design, in which
case the level of illumination is only one of the several factors to be taken into account.
Lighting Design
Lighting systems and equipment shall comply with the provisions of Energy Conservation
Building Code as outlined below:
Interior spaces of buildings, Exterior building features, including facades, illuminated roofs,
architectural features, entrances, exits, loading docks, and illuminated canopies, and,Exterior
building grounds lighting that is provided through the building's electrical service.
Exceptions:
The following lighting equipment and applications shall not be considered when determining the
interior lighting power allowance, nor shall the wattage for such lighting be included in the
installed interior lighting power. However, any such lighting shall not be exempt unless it is an
addition to general lighting and is controlled by an independent control device.
1. Display or accent lighting that is an essential element for the function performed in
galleries, museums, and monuments,
2. Lighting that is integral to equipment or instrumentation and is installed by its
manufacturer,
3. Lighting specifically designed for medical or dental procedures and lighting integral to
medical equipment,
4. Lighting integral to food warming and food preparation equipment,
5. Lighting for plant growth or maintenance,
6. Lighting in spaces specifically designed for use by the visually impaired,
7. Lighting in retail display windows, provided the display area is enclosed by ceiling height
partitions,
8. Lighting in interior spaces that have been specifically designated as a registered interior
historic landmark
9. Lighting that is an integral part of advertising or directional signage,
10. Exit signs
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11. Lighting that is for sale or lighting educational demonstration systems,
12. Lighting for theatrical purposes, including performance, stage, and film or video
production
13. Athletic playing areas with permanent facilities for television broadcasting.
Interior Lighting Power and Design
The installed interior lighting power for a building shall not exceed the interior lighting power
allowance determined in accordance with either Table 3 or 4.
Building area method
Determination of interior lighting power allowance (watts) by the building area method
shall be in accordance with the following:
Determine the allowed lighting power density from Table 3 for each appropriate building
area type.
Calculate the gross lighted floor area for each building area type.
The interior lighting power allowance is the sum of the products of the gross lighted floor
area of each building area times the allowed lighting power density for that building area
types.
Space Function Method
Determination of interior lighting power allowance (watts) by the space function method
shall be in accordance with the following:
Determine the appropriate building type as per the proposed use and the allowed lighting
power density.
For each space enclosed by partitions 80% or greater than ceiling height, determine the
gross interior floor area by measuring to the center of the partition wall. Include the floor
area of balconies or other projections. Retail spaces do not have to comply with the 80%
partition height requirements.
The interior lighting power allowance is the sum of the lighting power allowances for all
spaces. The lighting power allowance for a space is the product of the gross lighted floor
area of the space times the allowed lighting power density for that space.
Table 3 Interior Lighting Power - Building Area Method
In cases where both a general building area type and a specific building area type are listed, the
specific building area type shall apply.
Building Area Type LPD (W/m2) Building Area Type LPD (W/m2)
Automotive Facility 9.7 Multifamily Residential 7.5
Convention Center 12.9 Museum 11.8
Dining: Bar Lounge/Leisure 14.0 Office 10.8
Dining: Cafeteria/Fast Food 15.1 Parking Garage 3.2
Dining: Family 17.2 Performing Arts Theater 17.2
Dormitory/Hostel 10.8 Police/Fire Station 10.8
Gymnasium 11.8 Post Office/Town Hall/ 11.8
Healthcare-Clinic 10.8 Religious Building 14.0
Hospital/Health Care 12.9 Retail/Mall 16.1
Hotel 10.8 School/University 12.9
Library 14.0 Sports Arena 11.8
Manufacturing Facility 14.0 Transportation 10.8
Motel 10.8 Warehouse 8.6
Motion Picture Theater 12.9 Workshop 15.1
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Table 4: Interior Lighting Power –Space Function Method
Space Function LPD (W/m2) Space Function LPD (W/m2)
Office-enclosed 11.8 Library
Office-open plan 11.8 Card File & Cataloging 11.8
Conference/Meeting/Multipurpose 14.0 Stacks 18.3
Classroom/Lecture/Training 15.1 Reading Area 12.9
Lobby 14.0 Hospital
For Hotel 11.8 Emergency 29.1
For Performing Arts Theater 35.5 Recovery 8.6
For Motion Picture Theater 11.8 Nurse Station 10.8
Audience/Seating Area 9.7 Exam Treatment 16.1
For Gymnasium 4.3 Pharmacy 12.9
Patient Room 7.5
For Convention Center 7.5 Operating Room 23.7
For Religious Buildings 18.3 Nursery 6.5
For Sports Arena 4.3 Medical Supply 15.1
For Performing Arts Theater 28.0 Physical Therapy 9.7
For Motion Picture Theater 12.9 Radiology 4.3
For Transportation 5.4 Laundry – Washing 6.5
Atrium-first three floors 6.5 Automotive – Service Repair 7.5
Atrium-each additional floor 2.2 Manufacturing
Lounge/Recreation 12.9 Low Bay (<8m ceiling) 12.9
For Hospital 8.6 High Bay (>8m ceiling) 18.3
Dining Area 9.7 Detailed Manufacturing 22.6
For Hotel 14.0 Equipment Room 12.9
For Motel 12.9 Control Room 5.4
For Bar Lounge/Leisure Dining 15.1 Hotel/Motel Guest Rooms 11.8
For Family Dining 22.6 Dormitory – Living Quarters 11.8
Food Preparation 12.9 Museum
Laboratory 15.1 General Exhibition 10.8
Restrooms 9.7 Restoration 18.3
Dressing/Locker/Fitting Room 6.5 Bank Office – Banking Activity Area 16.1
Corridor/Transition 5.4 Retail
For Hospital 10.8 Sales Area 18.3
For Manufacturing Facility 5.4 Mall Concourse 18.3
Stairs-active 6.5 Sports Arena
Active Storage 8.6 Ring Sports Area 29.1
For Hospital 9.7 Court Sports Area 24.8
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
Installed Interior Lighting Power
The installed interior lighting power calculated for all power used by the luminaires, including
lamps, ballasts, current regulators, and control devices except as specifically exempted in the
previous paragraph. If two or more independently operating lighting systems in a space are
controlled to prevent simultaneous user operation, the installed interior lighting power shall be
based solely on the lighting system with the highest power.
Luminaire Wattage
Luminaire wattage incorporated into the installed interior lighting power shall be determined in
accordance with the following:
a. The wattage of incandescent luminaires with medium base sockets and not containing
permanently installed ballasts shall be the maximum labeled wattage of the luminaires.
b. The wattage of luminaires containing permanently installed ballasts shall be the operating
input wattage of the specified lamp/ballast combination based on values from
manufacturers’ catalogs or values from independent testing laboratory reports.
c. The wattage of all other miscellaneous luminaire types not described in (a) or (b) shall be
the specified wattage of the luminaires.
d. The wattage of lighting track, plug-in busway, and flexible-lighting systems that allow the
addition and/or relocation of luminaires without altering the wiring of the system shall be
the larger of the specified wattage of the luminaires included in the system or 135 W/m (45
W/ft). Systems with integral overload protection, such as fuses or circuit breakers, shall be
rated at 100% of the maximum rated load of the limiting device.
Luminiare efficiency
The efficiency of a luminare is the percentage of lamp lumens produced that exit the fixture. Use
of louvers improve visual comfort, reduce glare but reduces efficiency. It is thus important to
determine the best compromise between efficiency and visual comfort probability while choosing
luminaries. A lighting simulation is necessary to determine the type of luminaire and lamp
combination for a specific application. Efficient luminare also plays an important role for energy
conservation in lighting. The choice of a luminare should be such that it is efficient not only
initially but also throughout its life.
Following luminaries are recommended by the NBC 2005 for different locations:
a. For offices semi-direct of luminaries are recommended so that both the work plane
illumination and surround luminance can be effectively enhanced.
b. For corridors and staircases direct type of luminaries with wide spread of light distribution
are recommended.
c. In residential buildings, bare fluorescent tubes are recommended. Wherever the
incandescent lamps are employed, they should be provided with white enamelled conical
reflectors at an inclination of about 45°from vertical.
Inactive Storage 3.2 Indoor Field Area 15.1
For Museum 8.6 Warehouse
Electrical/Mechanical 16.1 Fine Material Storage 15.1
Workshop 20.5 Medium/Bulky Material Storage 9.7
Sleeping Quarters 3.2 Parking Garage – Garage Area 2.2
Convention Center – Exhibit Space 14.0 Transportation
Airport – Concourse 6.5
Air/Train/Bus – Baggage Area 10.8
Terminal – Ticket Counter 16.1
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Ballasts
All discharge lamps, including fluorescents, require ballast for proper operation. Typical ballast
losses are taken as approximately 15% of the lamp wattage. It is important to include calculation
of ballast losses when comparing consumption and savings fo different kinds of lamps. New
electronic or solid state ballasts, now available in market, save approximately 20—30% in energy
consumption over standard ballasts.
Lamps available in market
There are lamps that can deliver all the above qualities and still consume less than half the
electricity of some other (mostly technologically older) types. The reduction in energy consumption
is possible with proper choice of lighting fixtures and the lamp types. Lighting output and wattage
should be seen before choosing the lights. There are four types of lights commonly used in houses
these are:
Incandescent lamps
Incandescent lamps are the oldest electrical light sources and produce light by
the electric heating of a filament to such a high temperature that radiation in the
visible region of the spectrum is emitted. GLS (general lighting service) lamp is
shown in figure. The HPS lamps radiate energy across a large part of the visible
spectrum, but give a moderately poor colour rendering they have a distinct yellow
or golden appearance. Due to the high efficacy, they are commonly used for
lighting of public places.
Fluorescent lamps.
The lamp, in the form of a long tubular bulb with an electrode sealed into each end, contains
mercury vapour at low pressure with a small amount of inert gas for starting and regulation.
Standard fluorescent lamps
They are 40-W lamps with a diameter of 38 mm. Their lumen output varies
between 2450 lm and 2270 lm, and colour temperature from warm water
(4300 K) to cool daylight (6500 k). They are also available in 20 W and 80
W.
T5 lamps
These are fluorescent lamps with a diameter of 16 mm, which is 40% less
than the diameter of existing slim fluorescent lamps. They are designed for
higher efficacy and system miniaturization. The daylight life of T5 lamps is
also very long, around 18 000 hours as compared to 8000 hours of
standard fluorescent lamps.
Compact Fluorescent Lamps
CFLs (Compact fluorescent lamps) produce light in the same manner as linear fluorescent lamp.
Their tube diameter is usually 5/8 inch (T5) or smaller. CFL power is 5-55W. Typical CFLs have
been presented in figure
Keeping all the above in mind, there are lamps that can deliver all the
above qualities with comparatively less consumption of electricity of
some other (mostly technologically older) types. Bureau of Energy
Efficiency (BEE) has labelled these lamps and one can obtain the list
of BEE labelled lamps on its official website.
Light Emitting Diodes:
A Light Emitting Diode (LED) is a semiconductor device which converts electricity to light. Though
it has been in around since 1960, it is only until now that it is being explored for residential and
commercial application . Each diode is about 1/4 inch in diameter and operates at about a tenth of a watt. LEDs are small in size but can be grouped together for higher intensity. The efficacy of
Fig 1 Incandescent Lamp
Fig 2 Fluorescent Linear Lamps
Fig 3 Compact Fluorescent Light
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
a typical residential application LED is approximately 20 lumens per watt though 100 lumens per
watt have been created in laboratory conditions. LEDs are better at placing lighting in a single
direction than incandescent or fluorescent bulbs. LED strip lights can be installed under counters, in hallways, and in staircases; concentrated arrays can be used for room lighting.
Waterproof, outdoor fixtures are also available. Some manufacturers consider applications such
as gardens, walkways, and decorative fixtures outside garage doors to be the most cost-efficient.
LED lights are more rugged and damage-resistant than compact fluorescents and incandescent
bulbs. LED lights don't flicker. They are very heat sensitive; excessive heat or inappropriate
applications dramatically reduce both light output and lifetime. Uses include:
Task and reading lamps
Linear strip lighting (under kitchen cabinets)
Recessed lighting/ceiling cans ·
Porch/outdoor/landscaping lighting
Art lighting
Night lights
Stair and walkway lighting
Pendants and overhead
Retrofit bulbs for lamps
LEDs last considerably longer than incandescent or fluorescent lighting. LEDs don't typically
burn out like traditional lighting, but rather gradually decrease in light output.
Ultrasonic sensors –
These detect movement by sensing disturbances in high-frequency ultrasonic patterns. Because
this technology emits ultrasonic waves that are reflected around the room surfaces, it does not
require a direct line of sight. It is more sensitive to motion towards and away from the sensor and
its sensitivity decreases relative to its distances from the sensor. It also does not have a definable
coverage pattern or field of view. These characteristics make it suitable for use in layer-enclosed
areas that may have cabinets, shelving, partitions, or other obstructions. If necessary, these
technologies can also be combined into one product to improve detection and reduce the
likelihood of triggering a false on or off mode.
Photocells
These measure the amount of natural light available and suitable for both indoor and outdoor
applications. When available light falls below a specified level, a control unit switches the lights
on (or adjusts a driver to provide more light). Photocells can be programmed so that lights do not
flip on and off on partially cloudy days
Case Study of lighting design of a large office room
Energy efficient lighting optimisation
The main objective of lighting system optimisation is to achieve energy efficiency as recommended
in the Energy Conservation Building Code (ECBC) 2007 without compromising on visual comfort
requirements of the National Building Code (NBC) 2005.
Cost effectiveness of a lighting scheme is also considered as an important factor in optimisation
process. The lighting design optimisation has been carried out for typical room. The lighting
analysis has been done using standard lighting simulation software for various areas as
mentioned above.
Philips Lighting India Ltd has provided the electronic photometric files, which are used in the
software for analysis. The methodology followed for the lighting design optimisation is as follows:
Step 1: Analysis of lighting schemes as proposed by the architect/ consultant using lighting
simulation software. Check the conformance of calculated lighting levels with recommended
lighting levels in National Building Code (NBC) 2005Check the conformance of calculated
lighting power densities (LPD) defined as ratio of connected lighting load to built-up area
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
(W/m2) with recommended LPDs in Energy Conservation Building Code (ECBC) 2007.
Step 2: Modification of proposed lighting scheme if required to meet NBC 2005 recom-
mended lighting levels.
Step 3: Design and recommend an optimised lighting scheme meeting recommendations of
both NBC 2005 and ECBC 2007.
Step 4: Life cycle cost analysis of proposed, modified and recommended lighting schemes
Step 1: Analysis of the proposed lighting scheme:
Assumptions
The following assumptions have been made for the analysis.
Project maintenance factor : 0.8
Reflectance of ceiling : 0.7
Reflectance of walls : 0.5
Reflectance of floor : 0.1
Luminaire type : Batten type fixture equivalent to Philips TMC501
Lamp type : 40W fluorescent lamps (2450 lm)
The lighting schemes and calculated lighting levels of a typical room is as follows:
Table 5 : Calculated lighting levels for typical large rooms
Fig 4: Iso-contour diagram and rendered image of proposed case
Observations
It has been observed from the above Table-5 that the average lighting level of the above room is
well below the recommended lighting levels as per NBC-2005 standard. In order to provide
adequate visual comfort the proposed design need to be modified.
Step 2: Modified lighting schemes to meet NBC 2005 illumination levels.
Area Fixture type Lamp type No. of Fixture in
each area
Average Illumina-
tion Level
(Lux)
NBC Recom-
mended Illumina-
tion level
(Lux)
LPD
(W/m2)
ECBC Recom-
mended LPD
(W/m2)
Reading room
(Library)
TMC 501 or
equivalent with
copper ballast
1x 40W TLD 15 99.4 300 5.7 12.9
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The modified scheme along with calculated lighting level is given in table-6 below. The
assumptions taken in Step-1 also holds good for Step-2 analysis.
Table 6: Modified Schemes along with calculated lighting level
Fig 5: Iso-contour diagram and rendered image of modified case
Observations
As shown in the table 6, with modified lighting schemes the recommended illumination levels
have been achieved, however, the LPD in that room exceeds the recommended LPD of ECBC-2007
making designs highly energy inefficient. Therefore it is required to design lighting schemes in
such a way that will not only meet the required lighting level but also be energy efficient.
Step 3: Recommended lighting scheme:
Various combinations of efficient luminaire (luminaire with mirror optics reflector to reflect more
light to the work plane and bat wing louvers to control the glare effectively) with efficient lamps
having luminous efficacy more than the 40 W TL have been tried. Life cycle cost analysis was also
carried of few selected combinations. Based on performance, efficiency and cost the final
optimised scheme has been selected and it would include following lighting equipment.
1. Luminaire type : Philips TCS306 or equivalent with electronic ballast (as shown in
Annexure-2)
2 Lamp type :36 W tri-phosphor coated Fluorescent lamp with high lumen output of
3250 e.g., Philips Trulite
The performance (lighting levels) and efficiency (LPD) of optimized lighting schemes are given in
table below.
Table 7 Calculated lighting levels and LPD of optimized lighting schemes
Area
Fixture type Lamp Type No. of Fixture in
each area
Average Illumination
Level
(Lux)
NBC Recommended
Illumination level
(Lux)
LPD
(W/m2)
ECBC Recommended
LPD
(W/m2)
Reading
room(Library)
TMC 501 or equivalent
with copper ballast
1x 40W
TLD 48 313 300 18.4 12.9
Area Fixture type Lamp type No. of Fixture
in each area
Average Illumination Level
(Lux)
NBC Recom-
mended Illumina-
tion level
(Lux)
LPD
(W/m2)
ECBC Recom-
mended LPD
(W/m2)
Reading room
(Library)
TCS 306 or
equivalent with
2x 36W Trulite 15 306 300 7.5 12.9
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(The life cycle cost analysis for the proposed, modified and recommended schemes for a typical
space has been given in Annexure-1.)
Observations
It is quite evident from the above table-7 that the optimized lighting schemes in most of the
spaces provide illuminations, which conform to the recommended lighting levels as recommended
in NBC-2005. The calculated LPD of these schemes are also below the recommended LPD in
ECBC-2007.Therefore the optimized lighting schemes are recommended for various spaces in the
building.
Conclusion:
The main findings of the study are as follows:
With proposed design the illumination level is very low. No doubt, lighting load will be less but
this may cause visual discomfort and not advisable.
Inefficient lighting equipment may produce required illumination but at a higher energy
demand which will add to the existing energy problem.
Use of efficient lighting equipment will not only produce the required illumination but also
provide check on the increasing energy demand. Therefore it highly recommended using these
equipment in place of inefficient lighting equipment used in existing lighting schemes. Using
efficient lighting equipment will definitely increase the initial or first cost but the total cost or
the life cycle cost which includes both the first cost and recurring cost (energy & maintenance
cost) of such lighting schemes if calculated for a period of fifteen years comes out to be less
than the LCC of a system which is designed with cheaper and inefficient equipment to
produce same illumination.
References
1. A Knowledge Bank for Sustainable Building Design – CD, MNRE & TERI, New Delhi
2. Energy Conservation Building Code 2007, Bureau of Energy Efficiency, Ministry of Power,
3. Government of India·ICAEN (Institut catala d’ Energia), 2004, Building Design Manual,
TERI Press, New Delhi·
4. BIS, 1988, Handbook on Functional Requirements of Buildings, Bureau of Indian Stan-
dards, New Delhi·
5. BIS, 2005, National Building Code of India 2005, Bureau of Indian Standards, New Delhi.
6. Outputs from AGI 32: Lighting simulation tool
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
Life cycle cost analysis of a typical space
Space: Reading room (Library)
Architectural details
Length : 14.37 M
Width : 10.00 M
Height : 3.0M
Lighting schemes & equipment cost
i. Proposed/Modified lighting schemes
Luminaire type : Single TMC 501 with copper ballast
Cost of luminaire : Rs. 510/-
Type of lamp : 40 W ordinary tube light
Cost of lamp : Rs. 46/-
ii. Recommended lighting scheme
Luminaire type : Twin TCS 306 with electronic ballast
Cost of luminaire : Rs. 2640/-
Type of lamp : 36 W Trulite
Cost of lamp : Rs. 80/-
Operating hours : 8 hrs and 300 days a year
Electricity tariff : Rs 6/kWh
Table8: Calculated lighting levels & LPD of various Lighting Schemes
Table 9: Life Cycle Cost Analysis and savings of Lighting Schemes
S No. Lighting scheme Luminaire type Lamp type No. of fixtures No of lamp. Avg.Lighting Level (lux) LPD
(W/m2)
1 Case -1(proposed)
TMC501or eqivalent
with copper ballast 40W TL 15 15 192 5.7
2 Case -2(modified)
TMC501or eqivalent
with copper ballast 40W TL 48 48 313 18.8
3
Case- 3(recommended)
TCS 306 or equiva-
lent with Electronic
2x36 W Trulite 15 30 306 7.5
Sl.No. Lighting scheme Total Load
( kW)
Energy Consumption
(kWh)
Initial Cost
(Rs)
Life Cycle Cost
(Rs)
1 Case -1(proposed) 0.8 1980 8340 135465
2 Case -2(modified) 2.6 6336 26688 439564
3 Case- 3(recommended) 1.1 2592 42000 231323
Annexure 1
Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL
Fig 6 Life Cycle Cost graph for lighting schemes
Observation:
As can be seen in the graph above, the recommended luminaries would have an initial incre-
mental cost of Rupees 15312/- for the room, however the pay- back period would be less than
one year. As compared to the modified lighting scheme, an amount of Rupees 208241 /- would
be saved over a period of fifteen years by applying the recommended scheme.