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2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors Presented by: name title date California Commissioning Collaborative.

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Presentation on theme: "2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors Presented by: name title date California Commissioning Collaborative."— Presentation transcript:

1 2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors Presented by: name title date California Commissioning Collaborative

2 Title 24 2008 Acceptance Testing 2 What this talk will cover Description of acceptance testing requirements in 2008 Title 24 The motivation behind the requirements How acceptance testing affects design and specification practices How it impacts compliance documentation New responsibilities of the designer and the contractor Impacts on plan review and inspection

3 Title 24 2008 Acceptance Testing 3 Overview Building Efficiency a product of: –Materials and equipment –Installation and set-up –Occupant patterns and control Traditional standards –Specify materials, equipment, controls –Law of diminishing returns for more efficient equipment 2008 Title 24 standards – Acceptance Tests –Ensure equipment works as intended

4 Title 24 2008 Acceptance Testing 4 What is acceptance testing? Two components of acceptance testing –Construction inspection Is the specified equipment installed and calibrated? –Functional performance testing Does the equipment work as intended? Tests designed to uncover specification, installation or set-up problems Not replacing commissioning –Commissioning = broader scope

5 Title 24 2008 Acceptance Testing 5 Is acceptance testing needed? PIER Small Commercial HVAC survey* Small commercial buildings < 4 yrs old –64% of economizers failed Cooling energy increased by 37% –38% of supply fans cycling during occupancy Violation of Title 24 –30% unoccupied fan operation Increase of fan and heating energy –8% no outside air –8% simultaneous heating and cooling * http://www.energy.ca.gov/reports/2003-11-17_500-03-082.PDFhttp://www.energy.ca.gov/reports/2003-11-17_500-03-082.PDF

6 Title 24 2008 Acceptance Testing 6 Who benefits from acceptance tests? The designer –System installed and controlled according to code design intent –Reputation based on correct equipment operation The contractor –Technician’s work is reviewed –Fewer call-backs The owner –Equipment works right the first time –Energy cost savings Society –Less pollution associated with reduced energy consumption

7 Title 24 2008 Acceptance Testing 7 Acceptance Tests Required self-certification that equipment and systems were tested and work as intended Requires someone with a license to sign off on the testing (architect, engineer or contractor) Only one test (air distribution efficiency) requires 3d party verification –Home Energy Rating Service (HERS)

8 Title 24 2008 Acceptance Testing 8 Resources 2008 Standards (Title 24) 2008 Standards Nonresidential Appendices NA 7 – Reference – not needed for design or testing 2008 Nonresidential Energy Standards Compliance Manual –Chapter 4 – Mechanical Systems –Chapter 10 – Acceptance Requirements –End of Manual – Compliance and Acceptance Forms CEC Resources –http://www.energy.ca.gov/title24/2008standards/http://www.energy.ca.gov/title24/2008standards/ –CEC Bldg Standards Hotline 1-800-772-3300

9 Title 24 2008 Acceptance Testing 9 Acceptance Chapter in Nonresidential Manual Overview of compliance process At-A-Glance – 2 page overview of test –Purpose  Estimated Time –Benefits  Warnings or Cautions –Instrumentation  Test conditions –Acceptance Criteria Detailed test description

10 Title 24 2008 Acceptance Testing 10 Acceptance and Compliance Forms Compliance forms –Filled out by designer –MECH-1-C (C for compliance) –Reviewed by plans checker Acceptance Forms –Filled out by person conducting test –Reviewed by person with a license –Usually contractor, TAB or commissioning agent –MECH-1-A to MECH (A for acceptance) –Collected by Inspector prior to CO (Certificate of Occupancy) Forms in Appendix A of the Nonresidential Compliance Manual

11 Title 24 2008 Acceptance Testing 11 Code Enforcement Process: Plans and Specifications Compliance documentation with equipment specification and forms –MECH-1C lists all tests and which equipment must be tested –MECH-3C lists design minimum outside air Criteria for outside air tests (NJ.3.1 & 3.2) Plan checker reviews and approves or asks for modifications –All AC systems should be listed with appropraite tests

12 Title 24 2008 Acceptance Testing 12 Code Enforcement Process: Testing and Inspection Installing contractor or other “eligible professional” conducts tests and fills out MECH-#A acceptance forms –Equipment fixed until it passes all tests Completed forms handed to inspector along with other documentation –Inspector makes sure documentation is filled out correctly –Incomplete documentation is returned to contractor Certificate of Occupancy granted when building is in full compliance

13 Title 24 2008 Acceptance Testing 13 Designer has a big impact on ease and cost of acceptance tests Designer clearly identifies tests –Problem if covered equipment not specified on MECH-1C form and later needs testing Designer specifies equipment –Pre-calibrated equipment is cheaper Designer builds in test capabilities –Test ports and pre-installed gauges –Valves for isolating equipment

14 Title 24 2008 Acceptance Testing 14 Key Statements in MECH-1C The plans meet code I am qualified to sign these forms List of all mechanical acceptance tests with blanks for: –Equipment to be tested –Checkboxes to indicate which tests apply to the equipment listed

15 Title 24 2008 Acceptance Testing 15 HVAC Acceptance Tests Defined in Standards’ Mandatory Section 125 Detailed in the Appendix NA7 Nonresidential Compliance Manual –Test Descriptions in Chapter 10 –Forms in Appendix A

16 Title 24 2008 Acceptance Testing 16 Acceptance Requirements (1 of 2) ACM Section and Test Standard Section Additional Standard Section Certificate of Acceptance NA 7.5.1.1 Variable Air Volume Systems Outdoor Air 125(a)1121MECH-2A NA 7.5.1.2 Constant Volume Systems Outdoor Air NA 7.5.2 Constant Volume Packaged HVAC Systems125(a)2122MECH-3A NA 7.5.3 Air Distribution125(a)3 124, 144(k) or 149(b)1DMECH-4A NA 7.5.4 (Air-Side) Economizer125(a)4144(e)MECH-5A NA 7.5.5 Demand Control Ventilation125(a)5121(c)3&4MECH-6A NA 7.5.6 Supply Fan Variable Flow Controls125(a)6144(c)2MECH-7A NA 7.5.7 Valve Leakage Test125(a)7 & 8144(j)2 or 3MECH-8A NA 7.5.8 Supply Water Temperature Reset Controls125(a)9144(j)4MECH-9A NA 7.5.9 Hydronic System Variable Flow Controls125(a)7144(j)6MECH-10A NA 7.5.10 Automatic Demand Shed Controls125(a)10122(h)MECH-11A Updated for 2008

17 Title 24 2008 Acceptance Testing 17 New Acceptance Requirements (2 of 2) for Compliance Credit Measures ACM Section and Test Standard Section Additional Standard Section Certificate of Acceptance NA 7.5.1.11 FDD for Packaged DX Systems125(a)11MECH-12A NA 7.5.1.12 FDD for AHUS and Zone Terminal Units125(a)12MECH-13A NA 7.5.1.13 Distributed Energy Storage DX AC Systems125(a)13MECH-14A NA 7.5.1.14 Thermal Energy Storage Systems125(a)14MECH-15A

18 Title 24 2008 Acceptance Testing 18 Acceptance Tests Always Applied to Single Zone Rooftop Units MECH-2A - Outdoor Air for CAV –Measured outside air within 10% of the values listed on MECH-3C MECH-3A - Constant Volume & Single- Zone Unitary –Verifies that sequence of operation is correct Setup and setback works Fan turns off – unoccupied period When fan off – O/A damper closed No simultaneous heating and cooling

19 Title 24 2008 Acceptance Testing 19 Acceptance Tests - Single Zone Rooftop Units – sometimes in order of likelihood MECH-5A - Economizer Controls –Only if the unit has an economizer MECH-6A - Demand Control Ventilation –Required for high density applications Retail (first floor) Auditoriums Schools are specifically exempt MECH-4A - Air Distribution Ducts –Duct leakage test –Only if > 25% of duct surface area outdoors or in ventilated attic (not plenum) –Change-outs ducts not inc conditioned space

20 Title 24 2008 Acceptance Testing 20 Acceptance Tests Always Applied to Variable Air Volume Systems MECH-2A - Outdoor Air for VAV –Measured outside air within 10% of the values listed on MECH-3C at high and low flowrate MECH-7A Supply Fan VAV –Fan slows down at lower loads –For DDC to zone, duct pressure drops MECH-5A - Economizer Controls –Systems over > 75,000 Btu/h required to have an economizer

21 Title 24 2008 Acceptance Testing 21 Direct Digital Control to the Zone System has a central automated control that receives feedback from all zones –Allows pressure reset of variable flow fans or pumps Pressure dropped until most open damper or coil valve is almost full open. Thus all zones have enough pressure. –Allows resetting of zone temperature in response to a utility signal (demand response) –Allows adjusting outside air in response to CO2 level in zones

22 Title 24 2008 Acceptance Testing 22 Acceptance Tests Frequently Applied to VAV Systems with DDC to the Zone MECH-11A Automatic Demand Shed Control –Setup in response to utility signal MECH-6A Demand Control Ventilation –Required for high density applications Retail (first floor) Auditoriums Exempted: Schools, healthcare, social service

23 Title 24 2008 Acceptance Testing 23 Acceptance Tests Usually Applied to Hydronic Systems MECH-8A - Valve Leakage Test –Check isolation valves on boilers and chillers –Test all valves on rest of system MECH-10A - Hydronic System Variable Flow Control –Under low coil load, fan speed drops –Under low coil load, system that is DDC to zone, pressure drops MECH-9A - Supply Water Temp. Reset –Reset required only for systems > 500,000 Btu/h. –If system has controls, test required

24 Title 24 2008 Acceptance Testing 24 Compliance forms end in “–C”

25 Title 24 2008 Acceptance Testing 25  5  VAV AHU 1 & 2 2  CHW System 1  CV RTU 1 to 5 Checks in red indicate tests that would always be done for these system types

26 Title 24 2008 Acceptance Testing 26 What is an acceptable package of acceptance tests All Acceptance Tests listed on MECH-1C are completed All signature blocks legible and signed All values filled in & specific to equipment –Identical values for all tests indicate tests not being conducted All tests should be “Passed”

27 Title 24 2008 Acceptance Testing 27 Changes in 2008 Revisions to MECH-1C Certificate of Compliance New Field Inspection Checklist New Installation Certificate (10-103(a)3A) Reorganized Acceptance Test Forms (Certificates of Acceptance) T24 2008 HVAC Forms

28 Title 24 2008 Acceptance Testing 28 The not so fine print Systems Acceptance. Before occupancy permit is granted … … all control devices shall be certified as meeting the Acceptance Requirements Systems Acceptance. Before occupancy permit is granted. All newly installed HVAC equipment must be tested using the Acceptance Requirements. The MECH-1C form is not completed and is not to be accepted by the building department unless the correct boxes are checked. The building inspector must receive the properly filled out and signed forms before the building can receive final occupancy. Do you see a pattern??

29 Title 24 2008 Acceptance Testing 29 New Field Inspection Checklist Filled out by designer or Title 24 documentation author (or automatically by compliance software) Used by field inspector to help identify critical components Title 24 2008

30 Title 24 2008 Acceptance Testing 30 Installation Certificate Completed by licensed person responsible for building construction or installation of the mechanical system Certifies that installed system meets code requirements Title 24 2008 There is no longer a MECH 1A Form!

31 Title 24 2008 Acceptance Testing 31 Project information (typical) Technician block (typical) Reviewer block (typical) Acceptance forms end in “-#A”

32 Title 24 2008 Acceptance Testing 32 People Qualified to Certify Tests “Responsible Person” California licensed engineer, or architect –Eligible under Division 3 of the Business & Professions Code... to take responsibility for the scope of work –Mechanical and civil engineers California licensed contractor

33 Title 24 2008 Acceptance Testing 33 California Contractors typically eligible to take responsibility for acceptance tests A General Engineering Contractor B General Building Contractor C-4 Boiler, Hot Water Heating System Fitting Contractor C-20 Warm-air Heating, Ventilation & Air Conditioning Contractor C-36 Plumbing Contractor C-38 Refrigeration Contractor C-43 Sheet Metal Contractor D-62 Air and Water Balancing C-10 Electrical Contractor (controls) C-7 Low Voltage Systems Contractor (controls) Other contractors with related classifications

34 Title 24 2008 Acceptance Testing 34 Construction inspection (typical) Functional Testing block (typical)

35 Title 24 2008 Acceptance Testing 35 Test summary (Typical)

36 Title 24 2008 Acceptance Testing 36 Completed acceptance tests are a condition of the Certificate of Occupancy Late installation of a given piece of equipment is no excuse All other equipment can be tested and a conditional permit granted for the late piece of equipment

37 Title 24 2008 Acceptance Testing 37 Simple Spot Tests – Summer Economizer Have contractor place all AC in cooling mode in early morning –All economizers should be open Have contractor place in heating mode –All economizers should be closed Have contractor place systems back in cooling mode –All economizers should close when it is hot out

38 Title 24 2008 Acceptance Testing 38 Simple spot tests VAV system – summer Have contractor set cooling setpoint low –Fan speed should increase – listen or look at VFD output Have contractor set cooling setpoint high –Fan speed should decrease

39 Title 24 2008 Acceptance Testing 39 Minimum Outdoor Ventilation Air Acceptance MECH-2A Appendix NA 7.5.1

40 Title 24 2008 Acceptance Testing 40 Why is minimum outside air important Too little O/A – sick building syndrome –Often too little O/A at low flow for VAV systems Too much O/A – huge energy penalty –Hot summer day - 3 tons extra cooling for each 1,000 cfm excess outside air. Without adjusted O/A – easily 100% excess outside air

41 Title 24 2008 Acceptance Testing 41 Outside air dampers When in heating mode or in cooling mode where bringing outside air would increase load on building… ….outside air dampers are set or controlled to allow the minimum outside air needed to protect health and dispel normal odors.

42 Title 24 2008 Acceptance Testing 42 Purpose of Outdoor Air Acc. Test Verification of minimum OutSide Air (OSA) as scheduled on plans Verification that minimum OSA is provided throughout the range of operation in a VAV system and at design for CV systems Measured CFM of minimum outside air at min flow and full flow must be within 10% of design CFM on MECH-3C

43 Title 24 2008 Acceptance Testing 43 Design Minimum Outside Air MECH-3C VAV-O = office space, VAV-A = assembly space, Min O/A in Column I VAV-O 1,000 0.15 150 5 75 150 160 350 400 400 300 N/A VAV-A 1,000 0.15 150 34 510 510 510 1,200 400 1,200 550 N/A Totals 39 660 670 0 Min O/A for MECH-2A 67 x 0.5 = 34

44 Title 24 2008 Acceptance Testing 44 Fixed Minimum OA Damper Position only allowed for constant volume systems Outdoor Air Intake Return Air Minimum Signal Pot. Signal from SAT Controller For VAV systems does NOT WORK since mixed air plenum pressure varies!! Outdoor air flow will vary proportional to supply air flow

45 Title 24 2008 Acceptance Testing 45 Test Procedure CV System 1.Disable economizer (if applicable) 2.Disable DCV (if applicable) 3.Measure and record OSA 4.Restore boxes, economizer and DCV controls Setup Test Clean up

46 Title 24 2008 Acceptance Testing 46 How to Disable an Economizer Drop high-limit control setpoint below current OA temperature or enthalpy (all controls), or Raise OA temperature or enthalpy reading above high limit control setpoint (DDC controls), or Disable economizer control block (DDC controls)

47 Title 24 2008 Acceptance Testing 47 How to Disable and Engage DCV Controls Disable DCV –Raise CO2 setpoint significantly above current CO2 reading (all controls) Engage DCV –Lower CO2 setpoint to lowest possible setpoint (all controls)

48 Title 24 2008 Acceptance Testing 48 How to Measure OSA AFMS (air flow monitoring station) –If part of the system Calibrated damper (if part of the system) Traverse of OSA louver/duct Traverse of SA and RA ducts (differential) For each test OSA must be +/-10% of design Note: on small packaged units you might have to provide a temporary sheet metal hood on the OSA intake to get a good reading

49 Title 24 2008 Acceptance Testing 49 Construction Inspection Calibration of AFMS or calibrated damper (if part of the system) Verify that there is a provision for dynamic control of OSA (if VAV) Verify that there is a provision for minimum OSA (if CV)

50 Title 24 2008 Acceptance Testing 50 VAV Acceptable O/A Control Dual Minimum Minimum damper position is set proportionally based on fan speed between setpoints determined when the fan is at full speed and minimum speed Low cost Affected by wind, stack effect, filter loading

51 Title 24 2008 Acceptance Testing 51 Example Method of Dynamic OSA Control: Injection Fan Signal from SAT Controller

52 Title 24 2008 Acceptance Testing 52 Outdoor Air Intake Return Air Signal from SAT Controller Example Method of Dynamic OSA Control: Fixed Damper with DP control ∆P correlated to flow for fixed orifice Can be 1 section or entire OA damper

53 Title 24 2008 Acceptance Testing 53 Test Procedure VAV System 1.Disable economizer (if applicable) 2.Disable DCV (if applicable) 3.Drive all boxes to minimum airflow 4.Measure and record OSA 5.Drive all boxes to design airflow 6.Measure and record OSA 7.Restore boxes, economizer and DCV controls 8.System passes if measured OSA in steps 4 & 6 are within 10% of design OSA Combine tests to save time and $$ –MECH-2A full airflow test with DCV disabled –MECH-6A. full airflow test with DCV enabled Setup Test 1 Test 2 Clean up

54 Title 24 2008 Acceptance Testing 54 How to Drive VAV Boxes Open Set zone cooling temperature setpoint below the current zone temperature (all controls) Override the VAV box airflow setpoint (DDC controls) With DDC controls you might want to specify preset functions to drive all boxes to design airflow and minimum airflow to speed up the tests Note: if you override the VAV box damper you may provide more than the design maximum airflow

55 Title 24 2008 Acceptance Testing 55 How to Drive System to Minimum Airflow Set zone cooling temperature setpoint above the current zone temperature (all controls) Override the VAV box control airflow setpoint (DDC controls, could be preset) Manually slow down fan until airflow is ~30% of design airflow (all controls, requires AFMS or duct traverse)

56 Title 24 2008 Acceptance Testing 56 Project information (typical) Technician block (typical) Reviewer block (typical)

57 Title 24 2008 Acceptance Testing 57 Title 24 2008 Construction inspection (typical) Testing block (typical)  1,910 2,000 3.2 mins  92. 5 95.5   1,850 2,000 3 mins AH 12 nd Floor Offices   Project XYC, Somewhere, California

58 Title 24 2008 Acceptance Testing 58 Test summary (Typical) AH 1 2 nd Floor Offices Project XYC, Somewhere, California 

59 Title 24 2008 Acceptance Testing 59 Reasons to Reject the MECH-2A Signatures or names are missing for technician or reviewer Ratio of measured flowrate to design outside air flow rate (Percent OSA) –>110% –<90% Suspicious if all tests: –Measured airflow equal to design airflow rate

60 Title 24 2008 Acceptance Testing 60 Packaged HVAC Controls MECH-3A

61 Title 24 2008 Acceptance Testing 61 Purpose Check thermostat, setpoints and scheduling controls Verify that heating, economizer and cooling are properly sequenced Verify operation in occupied and unoccupied modes

62 Title 24 2008 Acceptance Testing 62

63 Title 24 2008 Acceptance Testing 63 MECH-3A Functional Tests Simulate various operating modes –Heating load occupied, no-load occupied, heating load unoccupied, no load unoccupied, etc. –Each condition is a column on the table Check for various HVAC unit responses –Different responses represented by each row –Areas grayed out are incorrect responses –Areas with check boxes are correct responses Test and fix until under each operating mode only responses are those indicated by check box

64 Title 24 2008 Acceptance Testing 64

65 Title 24 2008 Acceptance Testing 65 Occupied Mode Test Procedure 1.Heating –Supply fan operates continuously –OSA is provided –No cooling occurs –Verify that all heating stages work 2.Dead Band –Supply fan operates continuously –OSA is provided –No heating or cooling occurs 3.Cooling –Supply fan operates continuously –OSA is provided –No heating occurs –Verify that all cooling stages work Note the cooling test is repeated under economizer acceptance

66 Title 24 2008 Acceptance Testing 66 How to drive the unit into heating, cooling or deadband Cooling –Move thermostat cooling setpoint below the current room temperature Dead Band –Move the thermostat cooling setpoint above the current room temperature, and –Move the thermostat heating setpoint below the current room temperature Heating –Move the thermostat heating setpoint above the current room temperature

67 Title 24 2008 Acceptance Testing 67 Unoccupied Mode Test Procedure 4.Heating –Supply fan cycles on with call for heating (and off when satisfied) –OSA is closed or cycles with supply fan –No cooling occurs 5.Dead Band –Supply fan is off –OSA damper is closed –No heating or cooling occurs 6.Cooling –Supply fan cycles on with call for heating (and off when satisfied) –OSA is closed or cycles with supply fan –No heating occurs Again, the cooling test is repeated under economizer acceptance

68 Title 24 2008 Acceptance Testing 68 How to move the unit into “unoccupied” mode Adjust the schedule so that the unit is scheduled off at the current time, or Reset the current time so that it is outside of the scheduled occupied period

69 Title 24 2008 Acceptance Testing 69 Override Mode Test Procedure 7.Enable after hours override –System goes to “occupied” mode –System returns to “unoccupied” mode after timed delay 8.Return system to normal operation –Reset all setpoints –Remove any jumpers

70 Title 24 2008 Acceptance Testing 70 How to activate the after-hours override Put the unit into “unoccupied” mode (see previous slide) Push the after-hours button on the thermostat

71 Title 24 2008 Acceptance Testing 71 Air-Side Economizer MECH-5A

72 Title 24 2008 Acceptance Testing 72 Purpose Check economizer installation and provision for exhaust or relief Test economizer operation When a call for cooling and it is cool outside the economizer brings in outside air Other times min O/A

73 Title 24 2008 Acceptance Testing 73 Overview References –Standard Sections §144(e) and §125(a)4 –Form MECH-5A –Non-Residential Appendix NA 7.5.4 –Nonresidential Compliance Manual 10.6.10 Scope –All new systems with air-side economizers –No functional testing required if economizer is factory installed and certified operational None certified currently

74 Title 24 2008 Acceptance Testing 74

75 Title 24 2008 Acceptance Testing 75 High Limit Switch

76 Title 24 2008 Acceptance Testing 76 Economizer Functional Testing Step 1:Disable demand control ventilation (DCV) systems (if applicable) Step 2:Enable the economizer and simulate a cooling demand –Economizer damper is 100 percent open and return air damper is 100 percent closed. –For systems > 75,000 Btu/h economizer is integrated 100 % open when the cooling demand can no longer be met by the economizer alone. –All applicable fans and dampers operate as intended to maintain building pressure. –The unit heating is disabled. Step 3:Disable the economizer and simulate a cooling demand. –Economizer damper closes to its minimum position. –All applicable fans and dampers operate as intended to maintain building pressure. –The unit heating is disabled Step 4:Simulate a heating demand and set the economizer so that it is capable of operating (i.e. actual outdoor air conditions are below lockout setpoint). –The economizer is at minimum position Step 5:Restore DCV systems and remove all system overrides

77 Title 24 2008 Acceptance Testing 77 How to Disable an Economizer Drop high-limit control setpoint below current OA temperature or enthalpy (all controls), or Raise OA temperature or enthalpy reading above high limit control setpoint (DDC controls), or Disable economizer control block (DDC controls) Do the opposite to enable economizer

78 Title 24 2008 Acceptance Testing 78

79 Title 24 2008 Acceptance Testing 79 VAV Supply Air Acceptance Test MECH-7A Drawing courtesy of Steven Taylor

80 Title 24 2008 Acceptance Testing 80 Purpose Check calibration and setpoint of pressure sensor for VAV systems Check stability of control on VAV systems at full and part load Make sure fan speed slows with reduced load, supply air pressure does not rise For DDC to zone system, system air pressure drops at reduced load

81 Title 24 2008 Acceptance Testing 81 Overview References –Standard Sections §144(c)2B, C & D and §125(a)6 –Non-Residential Appendix 7.5.6 –Nonresidential Compliance Manual 10.6.14 Scope –New VAV fans greater than or equal to 10 hp –Both prescriptive and performance approach

82 Title 24 2008 Acceptance Testing 82 Construction Inspection - Verify Discharge static pressure sensors are either factory calibrated or field-calibrated. The static pressure location, setpoint, and reset control meets the requirements of §144(c)2C and §144(c)2D. –Sensor Location so set point < 1/3 the total design static P (i.e. near the end of the duct) except for DDC to zone systems w/ pressure reset –If located below major duct splits, sensors in each major branch, take lowest value for control –DDC to Zone, Set Point Reset. pressure set point based on the zone w/ most need zone damper needing most pressure is nearly wide open.

83 Title 24 2008 Acceptance Testing 83 Construction Inspection

84 Title 24 2008 Acceptance Testing 84 Test Procedure You may have to disable SA temperature reset during this test to prevent unwanted flow fluctuations 1.Drive boxes to achieve design airflow (refer to min OSA test for how to do this) 2.Record measured SP (must be +/- 10% of setpoint) 3.Note if fan speed stabilizes within 5 minutes

85 Title 24 2008 Acceptance Testing 85 Test Procedure 4.Drive boxes to achieve minimum airflow (refer to min OSA test for how to do this) 5.Record measured duct static pressure (must be +/- 10% of setpoint) 6.For DDC to zone systems, pressure setpoint must be reduced 7.Note if fan speed stabilizes within 5 minutes

86 Title 24 2008 Acceptance Testing 86 Functional Performance Testing

87 Title 24 2008 Acceptance Testing 87 Demand Control Ventilation (DCV) MECH-6A

88 Title 24 2008 Acceptance Testing 88 Demand Control Ventilation Requirements (§121(c)4) Where DCV is applied, it must meet the following: –One sensor for each space that meets the criteria of 121(c)3B –Sensor must be CO2 –Sensor must be located in the breathing zone between 3’ and 6’ AFF or at the anticipated level of the occupant’s heads –Maintain setpoint of 600ppm + OSA ppm 400 PPM default or dynamically measured –No greater than design ventilation @ 15 cfm/person –No less than ventilation from Table 121-A (cfm/ft 2 ) –Design ventilation for spaces without DCV

89 Title 24 2008 Acceptance Testing 89 Do Return CO 2 Sensors Work? Return is diluted by other Zones and does not track the critical zone No. Separate sensors are needed in each high density space

90 Title 24 2008 Acceptance Testing 90 Purpose Check DCV calibration and installation Test DCV at: –High CO2 levels –Low CO2 levels

91 Title 24 2008 Acceptance Testing 91 Related Tests NA 7.5.1 Outdoor Air Acceptance NA 7.5.4 (Air-Side) Economizer Acceptance This test should be combined with minimum OSA and economizer acceptance tests to reduce time and costs

92 Title 24 2008 Acceptance Testing 92

93 Title 24 2008 Acceptance Testing 93 DCV Test Procedure Disable economizer controls Measure CO2 concentration –If dynamic control < 600 ppm above ambient concentration –Default ambient concentration 400 ppm, indoor air < 1,000 ppm Step 1:Simulate a signal at or slightly above the CO2 concentration setpoint required by §121(c)4C. Verify and document the following: –For single zone units, outdoor air damper modulates open to satisfy the total ventilation air called for in the Certificate of Compliance. –For multiple zone units, either outdoor air damper or zone damper modulate open to satisfy the zone ventilation requirements. Not required to have cfm greater than MECH-3C column I (design ventilation air cfm) Step 2: Simulate signal well below the CO2 setpoint. Verify : –For single zone units, outdoor air damper modulates to the design minimum value. –For multiple zone units, either outdoor air damper or zone damper modulate less open to satisfy the reduced zone ventilation requirements. CFM must be at least as much as MECH-3C Column D (Min CFM by Area) for DCV controlled zone + MECH-3C column I (design ventilation air cfm) for uncontrolled zones Step 3: Restore economizer controls and remove all system overrides initiated during the test.

94 Title 24 2008 Acceptance Testing 94 Overriding CO2 Controls To simulate high demand you need to decrease the sensor setpoint To simulate low demand you need to increase the sensor setpoint Best accuracy results from using calibrated gas

95 Title 24 2008 Acceptance Testing 95 Default is 400 ppm

96 Title 24 2008 Acceptance Testing 96 Duct Sealing Air Distribution Systems MECH-4A

97 Title 24 2008 Acceptance Testing 97 MECH-4-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 …. and verified as sealed by a HERS rater

98 Title 24 2008 Acceptance Testing 98 MECH-4-A Construction Inspection Drawbands –Stainless steel worm drive or –UV resistant nylon duct ties Duct leakage tests performed before access is blocked Duct tape not used unless with drawbands and mastic R-8 insulation Outdoor insulation protected from damage

99 Title 24 2008 Acceptance Testing 99

100 Title 24 2008 Acceptance Testing 100 MECH-4A Calculated supply fan flow Rated flow from capacity –400 cfm/ton –21.7 cfm/kBtuh heating only systems

101 Title 24 2008 Acceptance Testing 101 MECH4-A Leakage Test New Construction Seal all diffusers Pressurize system to 25 Pa (0.1 in WC) with fan with calibrated orifice (duct blaster) Measured leakage no greater than 6% of rated flow Likely conducted by HVAC contractor Verified by HERS rater

102 Title 24 2008 Acceptance Testing 102 MECH-4-A Duct testing

103 Title 24 2008 Acceptance Testing 103 MECH-4A Duct Testing Results New Construction or Alterations Alterations New

104 Title 24 2008 Acceptance Testing 104 MECH-4-A Duct Sealing on Retrofits §144(k), 149(b)1D&E Applies to small CV system with ducts outside or in unconditioned spaces when: –Ducts replaced –HVAC system is replaced or major repair (new compressor, new coil etc.) Existing duct leakage –≤15% of rated supply flow –>60% reduction of leakage prior to sealing ducts with all visible leaks sealed –Can’t get at the ducts and all visible leaks are sealed as certified by a HERS rater Exceptions –Asbestos –Existing ducts that were previously certified

105 Title 24 2008 Acceptance Testing 105 HERS Rater Sampling Test Validation All systems must best tested by person conducting acceptance tests Independent HERS rater verifies results through sampled re-testing of systems: –Verify the first system tested –Verify one out of the each group of 7 tested If that unit fails the test, test a second unit in the group of 7 if that fails test the other 5 in the group of 7 –Certify ALL of the tests made by the contractor –Enter all tests into the HERS database New groups of 7 applies to each new construction project (but not for retrofit)

106 Title 24 2008 Acceptance Testing 106 Automatic Demand Shed Controls

107 Title 24 2008 Acceptance Testing 107 Automatic Demand Shed Controls (122(h)) For systems with DDC to the zone: –Ability to reset thermostat setpoint up to 4°F on all “non-critical” zones through real or virtual DI. –System needs an adjustable rate of change for reset Shown by LBNL and Purdue to reduce on-peak demand by over 30%. Supported by ASHRAE Standard 55 (Table 5.2.5.2). All New!

108 Title 24 2008 Acceptance Testing 108 Overview References –Standard Sections §122(b)4, §122(h) and §125(a)10 –Non-Residential Appendix NA 7.5.10 –Nonresidential Compliance Manual 10.6.19 Scope –New DDC Zone Controls

109 Title 24 2008 Acceptance Testing 109 Purpose To make sure that the demand shed controls are programmed and work when engaged Demand shed controls gives the owner the opportunity to temporarily turn up t-stats in all non-critical areas 4  F a few hours per year. –Utility financial incentives –Less likely to have a black-out

110 Title 24 2008 Acceptance Testing 110 Automatic demand shed controls NA7.5.10.1 Construction Inspection Prior to Acceptance Testing, verify and document the following: –That the EMCS interface enables activation of the central demand shed controls. NA7.5.10.2 Functional Testing Step 1: Engage the global demand shed system. Verify : –Cooling setpoint in non-critical spaces increases by the proper amount. –Cooling setpoints in critical spaces do not change. Step 2: Disengage the global demand shed system. Verify : –Cooling setpoint in non-critical spaces return to their original values. –Cooling setpoint in critical spaces do not change.

111 Title 24 2008 Acceptance Testing 111

112 Title 24 2008 Acceptance Testing 112

113 Title 24 2008 Acceptance Testing 113 Beyond Scope for Today ACM Section and TestStandard Section NA 7.5.1.11 FDD for Packaged DX Systems125(a)11 NA 7.5.1.12 FDD for AHUS and Zone Terminal Units125(a)12 NA 7.5.1.13 Distributed Energy Storage DX AC Systems125(a)13 NA 7.5.1.14 Thermal Energy Storage Systems125(a)14 These tests are documented in the Non-Residential Appendices and Non-Residential Compliance Manual. They are only required when you seek a compliance credit.

114 Title 24 2008 Acceptance Testing 114 Summary Acceptance tests assure that design intent for energy savings is executed All heating and cooling systems have at least one associated acceptance test The designer identifies which tests get applied to which equipment on the MECH-1-C form Plans examiner reviews MECH-1C form to assure all equipment has applicable tests specified –Compliance forms are rejected and returned to applicant if all applicable HVAC systems and tests are not called out Fully COMPLETED acceptance test forms with all systems PASSING must be given to inspector before building receives Certificate of Occupancy. –Schedule a challenge test if results are suspicious

115 Title 24 2008 Acceptance Testing 115 Sample Questions Which compliance form lists all acceptance tests that must be conducted? Who can be a “responsible person” for the acceptance tests? Are acceptance tests a requirement for a certificate of occupancy? Which acceptance test requires a third party HERS verification? Are any tests valid without 3d party verification? What is done if a system does not pass an acceptance test?

116 Title 24 2008 Acceptance Testing 116 More questions What tests are always required on constant air volume systems? What tests are always required of VAV? What tests are usually required of VAV systems with DDC to the zone?

117 Title 24 2008 Acceptance Testing 117 Outdoor Air Acceptance Test Questions Which compliance form contains the design ventilation air information? Measured ventilation air cfm must be within what percentage of design ventilation air cfm? a)5%, b) 10%, c) 30%, d)50% For VAV, variable air volume, systems outside air must be measured at design (full) flow and at what other supply air flowrate?

118 Title 24 2008 Acceptance Testing 118 Packaged A/C Acceptance Test Questions Select all true answers below When is supply fan on during occupied hrs: a) Heating call, b) Cooling call, c) No call for either heating or cooling When is supply fan on during unoccupied hrs: a)Heating call, b) Cooling call, c) No call for either heating or cooling When is the outside air damper completely closed?

119 Title 24 2008 Acceptance Testing 119 Air-side Economizer Test Questions True or False –Economizer open when call for cooling and outside air temp is below high limit setpoint –Economizer is open when call for heating and outside air temp is below high limit setpoint –Economizer closed when call for cooling and outside air temp is above high limit setpoint –Construction inspection not required for factory installed economizer w/ CEC certification.

120 Title 24 2008 Acceptance Testing 120 Resources – 2008 Standard Energy Efficiency Hotline –E-mail: title24@energy.state.ca.us –Phone: 916-654-5106 or –Phone: 1-800-772-3300 (toll free in Calif.)

121 Title 24 2008 Acceptance Testing 121 Acknowledgements California Commissioning Collaborative Pacific Gas & Electric Company –Codes & Standards Program California Energy Commission –Tav Commins, Project Manager Mark Hydeman, Taylor Engineering Jon McHugh, McHugh Energy Consultants


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