2008 title 24 nonresidential hvac acceptance testing for building officials contractors n.
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2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors

2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors

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2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors

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

  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. 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. 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. 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 *

  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. 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. 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 • • CEC Bldg Standards Hotline 1-800-772-3300

  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. 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. 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. Code Enforcement Process: Testing and Inspection • Installing contractor or other “eligible professional” conducts tests and fills out MECH-#Aacceptance 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. 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. 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. 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. Acceptance Requirements (1 of 2) Updated for 2008

  17. New Acceptance Requirements (2 of 2)for Compliance Credit Measures

  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. 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. 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. 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. 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. 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. Compliance forms end in “–C”

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

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

  31. Project information(typical) Technician block(typical) Reviewer block(typical) Acceptance forms end in “-#A”

  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. 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. Construction inspection (typical) Functional Testing block (typical)

  35. Test summary(Typical)

  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. 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. 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. Minimum Outdoor Ventilation Air Acceptance MECH-2AAppendix NA 7.5.1

  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. 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. 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. Design Minimum Outside Air MECH-3CVAV-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. Fixed Minimum OA Damper Position only allowed for constant volume systems For VAV systems does NOT WORK since mixed air plenum pressure varies!! Outdoor air flow will vary proportional to supply air flow Outdoor Air Intake Minimum Signal Pot. Return Air Signal from SAT Controller

  45. Test Procedure CV System Disable economizer (if applicable) Disable DCV (if applicable) Measure and record OSA Restore boxes, economizer and DCV controls Setup Test Clean up

  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. 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. 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. 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. VAV Acceptable O/A ControlDual 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