2005 title 24 nonresidential acceptance requirements mechanical designer training presented by tav...

2005 Title 24 Nonresidential Acceptance Requirements

Mechanical Designer TrainingPresented by

Tav Commins

California Energy Commission

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Overview

First Energy Codes for California developed in 1973.

Code is updated every three years.

Residential Code and Nonresidential Code

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Overview

Two ways to comply (Prescriptive and Performance)

Prescriptive – Listed values for efficiency of equipment, walls and the maximum amount of glass that may be installed.

Performance – The building is modeled using a approved computer program.

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Overview

All conditioned buildings must comply with the energy code.

All nonconditioned commercial buildings must comply with the indoor lighting requirements.

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Overview

October 1st 2005 latest code revision went into place.

Commercial and Residential buildings now require verification that key pieces of equipment were installed properly.

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When must the tests be conducted?

All new construction

In existing buildings when that piece of equipment is replaced.

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Overview

Building Efficiency is a product of:Design, materials & equipment Installation and set-upOccupant patterns and control

Traditional standardsSpecify materials, equipment, controlsLaw of diminishing returns for more eff equip

2005 Title 24 Part 6 Energy StandardsAssure equipment works as intended

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What is Acceptance Testing?

Two components of acceptance testingConstruction inspection

Is the specified equipment that is required to be installed actually there

Equipment testingDoes the equipment work as intended

Functional “performance” tests

Does Not replace commissioningCommissioning – broader scope

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Project OverviewDefinition of Acceptance Testing Requirements

Acceptance Testing requirements are defined as the application of targeted inspection checks and testing to determine whether specific building systems conform to the criteria set forth in the Standards and to the plans and specifications.

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Is Acceptance Testing Needed?

PIER Small Commercial HVAC survey http://www.energy.ca.gov/reports/2003-11-17_500-03-082.PDF

Small commercial buildings < 4 yrs old 64% of economizers failed

Cooling energy increased by 37%

38% of supply fans cycling during occupancyViolation of Title 24, §121(c)1

30% unoccupied fan operationIncrease of fan and heating energy

8% no outside air8% simultaneous heating and cooling

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What Systems are Included

HVAC

All packaged HVAC systems

All built-up HVAC systems

Hydronic systems

Lighting Controls

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Acceptance Tests

Required self-certification that equipment was tested and works as intended by the Standards

Liability trail results from cheating on test

Only one test (air distribution efficiency-leakage) requires 3rd party testingHome Energy Rating Service (HERS)

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Resources

2005 Building Energy Efficiency Standards for Residential and Nonresidential (Title 24)2005 Nonresidential Energy Compliance ManualChapter 4 – Mechanical SystemsChapter 8 – Acceptance RequirementsEnd of Manual - Compliance and Acceptance

FormsCEC Resourceshttp://www.energy.ca.gov/title24CEC Bldg Standards Hotline (800)772-3300

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Acceptance Chapter (Chapter 8) Nonresidential Manual

Overview of compliance process

At-A-Glance - 2 page overview of testPurpose Estimated TimeBenefits Warnings or CautionsInstrumentation Test conditionsAcceptance Criteria

Detailed test description

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Acceptance and Compliance Forms

Found in Appendix A of the Nonresidential Manual

Compliance formsFilled out by designerMECH-1-C (C for compliance)

Acceptance FormsFilled out by person conducting testUsually contractor, TAB or commissioning agentMECH-1-A (A for acceptance)

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Compliance Forms

Compliance documentation with equipment specification and formsMECH-1-C lists all tests and which

equipment must by testedMECH-1-C lists designated personnel to

perform testsMECH-3-C lists design minimum outside air

Criteria for outside air tests (NJ.3.1 & 3.2)

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Acceptance Forms

Installing contractor or other “eligible professional” conducts tests and fills out MECH-#-A acceptance forms

Equipment test - until it passes all tests

Completed forms handed to inspector along with other documentation

Certificate of Occupancy Granted

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Designer Has a Big Impact on Ease and Cost of Acceptance Tests

Designer clearly identifies testsProblem if covered equipment not specified

on MECH-1-C form and later needs testing

Designer specifies equipmentPre-calibrated equipment is cheaper

Designer builds in test capabilitiesTest ports and pre-installed gagesValves for isolating equipment

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Key Statements in MECH-1-C

The plans meet codeI am qualified to sign these formsList of all mechanical acceptance tests with blanks for:Equipment to be testedWho will test equipment

Installing Contractor Design ProfessionalAgent Selected by Owner

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MECH-1-C Note to Bidders

“Since the MECH-1-C will be part of the plans, completion of this section will allow the responsible party to budget accordingly”

Be careful to budget appropriately

Make note of this section to potential bidders

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Compliance forms end in “–C”

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People Certified to Perform Tests

The installing contractor, engineer of record, TAB contractor, or owner’s agent (i.e. 3rd party Cx provider)

The building inspector has the authority to require the Acceptance Agent to demonstrate competence, to his/her satisfaction

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Equipment Specification

Equipment specification can reduce level of acceptance testing and cost Thermostats with Pre-programmed schedules

Factory calibrated sensors with documentation Pressure sensor for Variable Frequency Drive (VFD) control Air flow monitoring station Demand Control Ventilation (DCV) CO2 sensor

calibrated ± 75 ppm Supply water temp reset sensor

Alternative is field calibration against reference sensor by using acceptance protocols

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Air-side acceptance test forms

Acceptance Forms ACM Section and Test

MECH-2-ANJ 3.1 Variable Air Volume Systems Outdoor Air

NJ 3.2 Constant Volume Systems Outdoor Air

MECH-3-A NJ 4.1 Constant Volume Packaged HVAC Systems

MECH-4-A NJ 7.1 (Air-side) Economizer

MECH-5-A NJ 5.1 Air Distribution

MECH-6-A NJ 8.1 Demand Control Ventilation

MECH-7-A NJ 9.1 Supply Fan Variable Flow Controls

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Hydronic Acceptance Forms

Acceptance Forms ACM Section and Test

MECH-8-A

NJ 10.1 Variable Flow Controls

NJ 10.2 Automatic Isolation Controls

NJ 10.3 Supply Water Temperature Reset Controls

NJ 10.4 Water-loop Heat Pump Controls

NJ 10.5 Variable Frequency Drive Controls

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MECH-2-A Outside Air

Same form used to document outside air acceptance for:CAV – constant air volume NJ.3.2VAV – variable air volume NJ.3.1

Measured minimum outside air must be within 10% of design minimum outside air

Test and Balance (TAB) contractor is probably the best qualified and has proper flow measurement tools available

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MECH-2-A VAV Outdoor Air

“Sensor used to control outdoor air flow must have calibration certificate or be field calibrated”Air flow monitoring stationPressure across dedicated fixed damper

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MECH-2-A VAV Outdoor Air

Contractor must set minimum outdoor air within 10% of design outdoor air at full flow and at minimum flow

Control strategies discussed in Mechanical Chapter of Nonresidential Manual

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MECH-2-A Outside Air Measurement

Calibrated air flow station

Pitot traverse in a straight section of duct

Pitot traverse across O/A inlet

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MECH-3-A Constant Volume Packaged HVAC Test

Thermostats or zone temperature controlThermostat or zone temperature sensor is

located in zone served by unitT-stat has capability of 5º deadband between

heating and coolingOccupied, unoccupied and holiday schedule

programmedOne hour pre-occupancy “purge” – turns on

fans 1 hour before occupied.Set-up and set-backs programmed as per

design instructions

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MECH-3-A Constant Volume Packaged HVAC Systems

Residential thermostats won’t workOccupied: Fan must run continuously Unoccupied: Fan runs intermittently to supply load

Timed manual override of unoccupied settings

Outside air damper positionMinimum position during occupied periodClosed during unoccupied periods

Test likely conducted by HVAC contractor and perhaps Controls contractor

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MECH-4-A Economizer Construction Inspection

Likely performed by HVAC contractorHigh limit setpoint not greater than listed in Table 144-C per Standards Section 144(e)3High limit sensors are factory calibrated with calibration

certificate or field calibrated. Which is easier?

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MECH-4-A Economizer Construction Inspection

Integrated economizer §144(e)2BCapable of providing partial cooling even when

additional mechanical cooling is needed to meet the load

EMS systems – cooling coil modulates to provide remainder of load

Stand-alone systems – two stage thermostat is minimally compliant

When outdoor air temp below high limit, economizer provides 1st stage coolingWhen O/A > high limit first stage of cooling provided by compressor2nd stage of cooling provided by compressor

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MECH-4-A EconomizerEquipment testing

Not required if economizer is factory installed and testedAttach manufacturer’s certification

Field installed or if no factory certification Simulate cooling load and enable economizer

O/A damper opens, return damper closes and relief is provided by relief damper or exhaust damperMechanical cooling enabled only if economizer can’t meet load

Simulate cooling load and disable economizerO/A damper closes, return damper opensMechanical cooling enabled

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MECH-5-A Air Distribution §144(k)

Small (<5,000 sf) CV systems only

When > 25% of duct surface is outdoors or in unconditioned space

Place greater than 75% of ducts under insulated roof – test not needed

Ducts must be tested for duct leakage by the installing contractor and verified by a 3rd party HERS rater.

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MECH-5-A Construction Inspection

DrawbandsStainless steel worm drive or UV resistant nylon duct ties

Must use UL 181 tape or mastic

Cloth backed duct tape not used unless with drawbands and mastic

R-8 insulation on all ducts in unconditioned spaces

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MECH-5-A Duct testing

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MECH5-A Leakage TestNew Construction

Rated flow from capacity400 cfm/ton21.7 cfm/kBtuh heating only systems

Seal all diffusersPressurize system to 25 Pa (0.1 in WC) with fan with calibrated orifice (duct blaster)Measured leakage no greater than 6% of rated flowConducted by HVAC contractor. Must seal all leakesVerified by HERS rater

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MECH-5-A Duct Sealing on Retrofits§144(k), 149(b)1D&E

Applies to small Constant Volume system with ducts in unconditioned spaces when:Any amount of ducts replaced or added, orChangeout of HVAC system, or Major repair (new condenser, new coil)

Existing ducts:Leakage ≤15% of rated supply flow, or>60% reduction of leakage prior to sealing ducts with all

visible leaks sealed, orCan’t access the ducts and all visible leaks are sealed as

certified by a HERS raterExceptionsAsbestosExisting ducts that were previously certified

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MECH-6-A Demand Control Ventilation

Likely conducted by controls contractorConstruction InspectionSensor mounted in room between 1 and 6

ft from floorCalibration

Factory calibrated with manufacturer’s certification of ± 75 ppm accuracyField calibrated using reference gas or reference sensorWhich is easier?

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MECH-6-A DCV Equipment Test

Simulate a high CO2 loadDecrease CO2 setpoint or breathe on

sensorOutside air damper modulates open

To design outside air setting from MECH-3-C

Simulate a low CO2 loadIncrease CO2 setpoint, don’t breath on

sensorOutside air modulates to minimum position

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MECH-7-A Supply Fan Variable Frequency Drive

Construction inspectionFactory calibrated pressure sensors with certificate

(don’t lose these!)Field calibration against a reference sensor

Equipment testingFull flow – all boxes calling for cooling

Measured pressure within 10% of control pressure

Reduced flow – boxes not calling for coolingMeasured pressure within 10% of control pressure

Reduced flow pressure ≤ full flow pressure

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MECH-8-A Hydronic Tests

Construction inspectionConfirm piping, sensors and controls are

located as shown on plansSensors are factory calibrated or field

calibratedTemperature for temperature reset

Pressure for VFD control

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Summary

Acceptance tests assure that your design intent for energy savings is executedMost automatic controls have an associated acceptance testThe designer identifies which tests get applied to which equipment on the MECH-1-C formConstruction bids need to account for the costs of conducting and documenting the acceptance testsSpecifying factory calibrated and factory installed equipment can dramatically reduce testing costsSome designs reduce the amount of testing needed ducts run under an insulated roof factory installed economizers

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Resources – 2005/2008 Standard

Energy Efficiency Hotline

Open 8:00 to 12:00 and 1: to 4:30E-mail: title24@energy.state.ca.usPhone: 916-654-5106 orPhone: 1-800-772-3300http://www.energy.ca.gov/title24/California Commissioning Collaborative

www.cacx.org

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QuestionsUm Bob, I

have a question….