2005 Title 24 Nonresidential Acceptance Requirements
Mechanical Designer TrainingPresented by
Tav Commins
California Energy Commission
2
Overview
First Energy Codes for California developed in 1973.
Code is updated every three years.
Residential Code and Nonresidential Code
3
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.
4
Overview
All conditioned buildings must comply with the energy code.
All nonconditioned commercial buildings must comply with the indoor lighting requirements.
5
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.
6
When must the tests be conducted?
All new construction
In existing buildings when that piece of equipment is replaced.
7
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
8
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
9
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.
10
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
11
What Systems are Included
HVAC
All packaged HVAC systems
All built-up HVAC systems
Hydronic systems
Lighting Controls
12
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)
13
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
14
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
15
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)
16
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)
17
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
18
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
19
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
20
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
21
Compliance forms end in “–C”
22
23
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
24
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
25
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
26
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
27
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
28
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
29
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
30
MECH-2-A Outside Air Measurement
Calibrated air flow station
Pitot traverse in a straight section of duct
Pitot traverse across O/A inlet
31
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
32
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
33
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?
34
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
35
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
36
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.
37
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
38
MECH-5-A Duct testing
39
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
40
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
41
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?
42
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
43
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
44
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
45
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
46
Resources – 2005/2008 Standard
Energy Efficiency Hotline
Open 8:00 to 12:00 and 1: to 4:30E-mail: [email protected]: 916-654-5106 orPhone: 1-800-772-3300http://www.energy.ca.gov/title24/California Commissioning Collaborative
www.cacx.org
47
QuestionsUm Bob, I
have a question….