HVAC Design, Equipment and Controls (A6.207)

Grounded in the retrieved California Green Building Standards Code (CALGreen) — click a citation to read the verbatim passage:

• CALGreen § 106.11. High relevance — show source text

  **Locate orient and shade the building as
  required in Section A6.106.11.||||| |SECTION A6.205 Building Envelope||||| |A6.205.1 Fenestration products and exterior doors.
  A6.205.1.1 Certification of fenestration products and exterior door other than field-
  fabricated.||||| |A6.205.1.2 Installation of field-fabricated fenestration and exterior doors.||||| |A6.205.2 Joints and other openings.||||| |A6.205.3 Installation and roofing products.|||||

  2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A6.1-37

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

  NONRESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST [OSHPD 1, 2 and 4] — continued

  FEATURE OR MEASURE	COMPLIANCE LEVELS	Col3	Col4	NOTES
  FEATURE OR MEASURE	Mandatory CALGreen	VOLUNTARY CALGreen	VOLUNTARY CALGreen	VOLUNTARY CALGreen
  FEATURE OR MEASURE	Mandatory CALGreen	Tier 1	Tier 2	Tier 2
  SECTION A6.207 HVAC Design, Equipment and Installation
  A6.207.1 Space-conditioning equipment certification by manufacturers. A6.207.1.1 Efficiency. A6.207.1.2 Controls for heat pumps with supplementary electric resistance heaters. A6.207.1.3 Thermostats. A6.207.1.4 Gas-and oil-fired furnace standby loss controls.		    	    
  A6.207.2 Space conditioning systems. A6.207.2.1 Supply air temperature reset controls. A6.207.2.2 Electric resistance heating. A6.207.2.3 Heat rejection systems. A6.207.2.4 Hydronic system measures. A6.207.2.5 Air distribution system duct leakage sealing. **A6.207.2.6 Variable air volume control for single zone systems.

• CALGreen § 802.3 High relevance — show source text

  (5) Building occupant and O&M personnel expectations E 802.3 Basis of Design (BOD). A written explanation of how the design of the HVAC system meets the owner’s project requirements shall be completed at the design phase of the building project, and updated as necessary during the design and construction phases. The basis of design document shall cover not less than the following systems:

  (1) Heating, ventilation, air conditioning (HVAC) systems and controls

  (2) Water heating systems

  (3) Renewable energy systems E 802.4 Commissioning Plan. A commissioning plan shall be completed to document the approach to how the project will be commissioned, and shall be started during the design phase of the building project. The commissioning plan shall include not less than the following:

  (1) General project information

  (2) Commissioning goals

  (3) Systems to be commissioned. Plans to test systems and components shall include not less than the following:

  (a) A detailed explanation of the original design intent.

  (b) Equipment and systems to be tested, including the extent of tests.

  (c) Functions to be tested.

  (d) Conditions under which the test shall be performed.

  (e) Measurable criteria for acceptable performance.

  (4) Commissioning team information.

  (5) Commissioning process activities, schedules, and responsibilities. Plans for the completion of commissioning requirements listed in Section E 802.5 through Section E 802.7 shall be included.

  E 802.5 Functional Performance Testing. Functional performance tests shall demonstrate the correct installation and operation of each component, system, and system-to-system interface in accordance with the approved plans and specifications. Functional performance testing reports shall contain information addressing each of the building components tested, the testing methods utilized, and readings and adjustments made.

  E 802.6 Post Construction Documentation and Train- ing. A system manual and systems operations training are required.

  E 802.6.1 Systems Manual. Documentation of the operational aspects of the HVAC system shall be completed within the systems manual and delivered to the building owner and facilities operator. The systems manual shall include not less than the following:

  (1) Site information, including facility description, history, and current requirements.

  (2) Site contact information.

  (3) Basic O&M, including general site operating procedures, basic troubleshooting, recommended maintenance requirements, and site events log.

  (4) Major systems.

  (5) Site equipment inventory and maintenance notes.

  (6) Equipment/system warranty documentation and information.

  (7) “As-Built” design drawings.

  (8) Other resources and documentation.

  E 802.6.2 Systems Operations Training. The training of the appropriate maintenance staff for each equipment type or system shall include not less than the following:

  (1) System/Equipment overview (what it is, what it does, and what other systems or equipment it interfaces with).

  (2) Review of the information in the systems manual.

  (3) Review of the record drawings on the system/equip ment.

  E 802.7 Commissioning Report. A complete report of commissioning process activities undertaken through the design, construction, and post-construction phases of the building project shall be completed and provided to the

  owner.

  Part II

  E 803.0 Commissioning Acceptance.

  E 803.1 General. Part II of this appendix provides a means of verifying the commissioning requirements of Section E 802.1. The activities specified in Part II of this appendix includes three aspects, as described as follows:

• CALGreen § 207.1.1 High relevance — show source text

  **
  A6.207.1.1 Efficiency.
  A6.207.1.2 Controls for heat pumps with supplementary electric resistance heaters.
  A6.207.1.3 Thermostats.
  A6.207.1.4 Gas-and oil-fired furnace standby loss controls.||
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  || |A6.207.2 Space conditioning systems.
  A6.207.2.1 Supply air temperature reset controls.
  A6.207.2.2 Electric resistance heating.
  A6.207.2.3 Heat rejection systems.
  A6.207.2.4 Hydronic system measures.
  A6.207.2.5 Air distribution system duct leakage sealing.
  A6.207.2.6 Variable air volume control for single zone systems.||
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  || |A6.207.3 Service water-heating systems and equipment.
  A6.207.3.1 Certification by manufacturers.
  A6.207.3.2 Efficiency.
  A6.207.3.3 Installation.||
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  || |A6.207.4 Natural gas central furnaces, cooking equipment and pool and spa heaters.
  Pilot lights prohibited.||||| |A6.207.5 Controls for space-conditioning systems.
  A6.207.5.1 Thermostatic controls for each zone.
  A6.207.5.2 Criteria for zonal thermostatic controls.
  A6.207.5.3 Heat pump controls.
  A6.207.5.4 Dampers for air supply and exhaust equipment.
  A6.207.5.5 Automatic demand shed controls.||
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  || |A6.207.6 Pipe insulation.||||| |SECTION A6.209 Lighting||||| |A6.209.1 Lighting control devices, ballasts and luminaires.
  A6.209.1.1 All devices: Instructions and calibration.
  A6.209.1.2 Indicator lights.
  **A6.209.1.3 Automatic time switch control devices.

• CALGreen § 801.0 High relevance — show source text

  Part I

  E 801.0 Heating, Ventilation, and Air Conditioning Systems Commissioning. E 801.1 Applicability. The provisions of this section apply to the commissioning of commercial and institutional HVAC systems.

  E 802.0 Commissioning. E 802.1 Commissioning Requirements. HVAC commissioning shall be included in the design and construction processes of the project to verify that the HVAC systems and components meet the owner’s project requirements and in accordance with this appendix. Commissioning shall be performed in accordance with this appendix by personnel trained and certified in commissioning by a nationally recognized organization. Commissioning requirements shall include the following:

  (1) Owner’s project requirements

  (2) Basis of design

  (3) Commissioning measures shown in the construction doc uments

  (4) Commissioning plan

  (5) Functional performance

  (6) Testing

  (7) Post construction documentation and training

  (8) Commissioning report

  2025 CALIFORNIA MECHANICAL CODE 479

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  APPENDIX E

  HVAC systems and components covered by this appendix as well as process equipment and controls, and renewable energy systems shall be included in the scope of the commissioning requirements. E 802.2 Owner’s Project Requirements (OPR). The performance goals and requirements of the HVAC system shall be documented before the design phase of the project begins. This documentation shall include not less than the following:

  (1) Environmental and sustainability goals

  (2) Energy efficiency goals

  (3) Indoor environmental quality requirements

  (4) Equipment and systems performance goals

  (5) Building occupant and O&M personnel expectations E 802.3 Basis of Design (BOD). A written explanation of how the design of the HVAC system meets the owner’s project requirements shall be completed at the design phase of the building project, and updated as necessary during the design and construction phases. The basis of design document shall cover not less than the following systems:

  (1) Heating, ventilation, air conditioning (HVAC) systems and controls

  (2) Water heating systems

  (3) Renewable energy systems E 802.4 Commissioning Plan. A commissioning plan shall be completed to document the approach to how the project will be commissioned, and shall be started during the design phase of the building project. The commissioning plan shall include not less than the following:

  (1) General project information

  (2) Commissioning goals

  (3) Systems to be commissioned. Plans to test systems and components shall include not less than the following:

  (a) A detailed explanation of the original design intent.

  (b) Equipment and systems to be tested, including the extent of tests.

  (c) Functions to be tested.

  (d) Conditions under which the test shall be performed.

  (e) Measurable criteria for acceptable performance.

  (4) Commissioning team information.

  (5) Commissioning process activities, schedules, and responsibilities. Plans for the completion of commissioning requirements listed in Section E 802.5 through Section E 802.7 shall be included.

  E 802.5 Functional Performance Testing. Functional performance tests shall demonstrate the correct installation and operation of each component, system, and system-to-system interface in accordance with the approved plans and specifications. Functional performance testing reports shall contain information addressing each of the building components tested, the testing methods utilized, and readings and adjustments made.

• CALGreen § 204.4.1 High relevance — show source text

  The owner shall document the Owner’s Project Requirements (OPR). The design team shall develop the Basis of Design (BOD). The CxA shall review these documents for clarity and completeness. The owner and design team shall be responsible for updates to their respective documents, develop and incorporate commissioning requirements into the construction documents and develop and implement a commissioning plan. The CxA shall verify the installation and performance of the systems to be commissioned, verify that training and operation and maintenance documentation have been provided to the owner’s operations staff and complete a commissioning report.

  Commissioning process activities shall be completed for the following energy-related systems, at a minimum:

  1. Heating, ventilating, air conditioning and refrigeration (HVAC&R) systems (mechanical and passive) and associated controls.
  2. Lighting and daylighting controls.
  3. Domestic hot water systems.
  4. Renewable energy systems (wind, solar, etc.).
  5. Building envelope systems.

  A6.204.4.1 Owner’s Project Requirements (OPR). The expectations and requirements of the building shall be documented by the owner and the designer before the design phase of the project begins. This shall be reviewed by the CxA. At a minimum, this documentation shall include the following:

  1. Environmental and sustainability goals.
  2. Energy efficiency goals.
  3. Indoor environmental quality requirements.

  2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A6.1-3

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

  4. Equipment and systems expectations.
  5. Building occupant and O&M personnel expectations.

  A6.204.4.2 Basis of Design (BOD). A written explanation of how the design of the building systems meets the Owner’s Project Requirements shall be completed at the design phase of the building project and updated as necessary during the design and construction phases. This shall be reviewed by the CxA. At a minimum, the Basis of Design document shall cover the following systems:

  1. Heating, ventilation, air conditioning (HVAC) systems and controls.
  2. Indoor lighting system and controls.
  3. Water heating system.
  4. Renewable energy systems.

  A6.204.4.3 Commissioning plan. A commissioning plan shall be completed to document the approach to how the project will be commissioned and shall be started during the design phase of the building project. This shall be reviewed by the CxA. The Commissioning Plan shall include the following at a minimum:

  1. General project information.
  2. Commissioning goals.
  3. Systems to be commissioned. Plans to test systems and components shall include at a minimum: a. A detailed explanation of the original design intent; b. Equipment and systems to be tested, including the extent of tests; c. Functions to be tested;

  d. Conditions under which the test shall be performed; and e. Measurable criteria for acceptable performance. 4. Commissioning team information. 5. Commissioning process activities, schedules and responsibilities – plans for the completion of commissioning requirements listed in Sections A6.204.4.4 through A6.204.4.6 shall be included.

• CALGreen § 120.8 High relevance — show source text

  Nonresidential buildings other than healthcare facilities, with conditioned space of 10,000 square feet or more, shall comply with the applicable requirements of Sections 120.8(a) through 120.8(i) in the building design and construction processes. All building systems and components covered by Sections 110.0, 120.0, 130.0, and 140.0 shall be included in the scope of the commissioning requirements in this Section, excluding those related solely to covered processes.

  Nonresidential buildings other than healthcare facilities, with conditioned space of less than 10,000 square feet shall comply with the design review requirements specified in Sections 120.8(d), and shall include any measures or requirements necessary for completing this review in the construction documents in a manner consistent with Section 120.8(e).

  Healthcare facilities shall instead comply with the applicable requirements of Chapter 7 of the California Administrative Code (Title 24, Part 1).

  NOTE: Nonresidential buildings include nonresidential spaces such as nonresidential function areas within hotel/motel and highrise residential buildings. The requirements of Section 120.8 apply based on the square footage of the nonresidential spaces.

  The commissioning described in this Section is in addition to any commissioning required by Title 24, Part 11, Section 5.410.2, 5.410.4 and subsections.

  (a) Summary of commissioning requirements. Commissioning shall include completion of the following items:

  1. Owner’s or owner representative’s project requirements;

  2025 CALIFORNIA ENERGY CODE 91

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  NONRESIDENTIAL, HOTEL/MOTEL OCCUPANCIES, AND COVERED PROCESSES—MANDATORY REQUIREMENTS

  2. Basis of design;
  3. Design phase design review;
  4. Commissioning measures shown in the construction documents;
  5. Commissioning plan;
  6. Functional performance testing;
  7. Documentation and training; and
  8. Commissioning report.

  (b) Owner’s or Owner Representative’s Project Requirements (OPR). The energy-related expectations and requirements of the building shall be documented before the design phase of the project begins. This documentation shall include the following:

  1. Energy efficiency goals;
  2. Ventilation requirements;
  3. Project documentation requirements, including facility functions, hours of operation, and need for after-hours operation;
  4. Equipment and systems expectations; and
  5. Building envelope performance expectations.

  (c) Basis of design (BOD). A written explanation of how the design of the building systems and components meets the OPR shall be completed at the design phase of the building project, and updated as necessary during the design and construction phases. The basis of design document shall cover the following systems and components:

  1. Heating, ventilation, air conditioning (HVAC) systems and controls;
  2. Indoor lighting system and controls;
  3. Water heating systems and controls;
  4. Any other building equipment or system listed in the OPR; and
  5. Any building envelope component considered in the OPR.

  (d) Design phase design review.

  1. Design reviewer requirements. The design reviewer shall be the signer of the Design Review Kickoff Certificate(s) of Compliance and Construction Document Design Review Checklist Certificate(s) of Compliance as specified in Part 1 Section 10-103(a)1.
  2. Design review kickoff. During the schematic design phase of the building project, the owner or owner’s representative, design team and design reviewer must meet to discuss the project scope, schedule and how the design reviewer will coordinate with the project team.
• CALGreen § 90.1 High relevance — show source text

  (1) Monitor zone damper positions or other indicator of need for static pressure.

  (2) Automatically detect those zones that are capable of excessively driving the reset logic and generate an alarm to the system operator.

  (3) Readily allow operator removal of zones from the reset algorithm. [ASHRAE 90.1:6.5.3.2.3]

  E 503.5.6.2.3 Return and Relief Fan Con-

  trol. Return and relief fans used to meet Section E 503.5.1.4 shall comply with all of the following:

  (1) Relief air rate shall be controlled to maintain building pressure either directly, or indirectly through differential supplyreturn airflow tracking. Systems with constant speed or multispeed supply fans shall also be allowed to control the relief system based on outdoor air damper position.

  (2) Fans shall have variable-speed control or other devices that will result in total return/relief fan system demand of no more than 30 percent of total design power at 50 percent of total design fan flow.

  2025 CALIFORNIA MECHANICAL CODE 437

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  APPENDIX E

  Exceptions:

  (1) Return or relief fans with total motor size less than or equal to 0.5 hp (0.37 kW).

  (2) Staged relief fans with a minimum of four stages. [ASHRAE 90.1:6.5.3.2.4]

  E 503.5.6.3 Multiple-Zone VAV System Venti- lation Optimization Control. Multiple-zone VAV systems with DDC of individual zone boxes reporting to a central control panel shall include means to automatically reduce outdoor air intake flow below design rates in response to changes in system ventilation efficiency in accordance with Section 404.0 or ASHRAE 62.1.

  Exceptions:

  (1) VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fanpowered terminal units.

  (2) Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake flow requirements. [ASHRAE 90.1:6.5.3.3]

  E 503.5.6.4 Supply Air Temperature Reset Controls. Multiple zone HVAC systems shall include controls that are capable of and configured to automatically reset the supply air temperature in response to representative building loads, or to outdoor air temperature. The controls shall reset the supply air temperature to at least 25 percent of the difference between the design supply air temperature and the design room air temperature. Controls that adjust the reset based on zone humidity shall be permitted in Climate Zones 0B, 1B, 2B, 3B, 3C, and 4 through 8. HVAC zone that are expected to experience relatively constant loads shall have maximum airflow designed to accommodate the fully reset supply air temperature.

  HVAC zones that are expected to experience relatively constant loads typically include electronic equipment rooms and interior zones.

  Exceptions:

  (1) Systems in Climate Zones 0A, 1A, and 3A with less than 3000 cubic feet per minute (1.4 m [3] /s) of design outdoor air.

• CALGreen § 90.1 High relevance — show source text

  Exceptions:

  (1) VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fanpowered terminal units.

  (2) Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake flow requirements. [ASHRAE 90.1:6.5.3.3]

  E 503.5.6.4 Supply Air Temperature Reset Controls. Multiple zone HVAC systems shall include controls that are capable of and configured to automatically reset the supply air temperature in response to representative building loads, or to outdoor air temperature. The controls shall reset the supply air temperature to at least 25 percent of the difference between the design supply air temperature and the design room air temperature. Controls that adjust the reset based on zone humidity shall be permitted in Climate Zones 0B, 1B, 2B, 3B, 3C, and 4 through 8. HVAC zone that are expected to experience relatively constant loads shall have maximum airflow designed to accommodate the fully reset supply air temperature.

  HVAC zones that are expected to experience relatively constant loads typically include electronic equipment rooms and interior zones.

  Exceptions:

  (1) Systems in Climate Zones 0A, 1A, and 3A with less than 3000 cubic feet per minute (1.4 m [3] /s) of design outdoor air.

  (2) Systems in Climate Zone 2A with less than 10 000 cubic feet per minute (4.7 m [3] /s) of design outdoor air.

  (3) Systems in Climate Zones 0A, 1A, 2A, and 3A with at least 80 percent outdoor air and employing exhaust air energy recovery complying with Section E 503.5.10.1.

  (4) Systems that prevent reheating, recooling, or mixing of heated and cooled supply air.

  (5) Systems in which at least 75 percent of the energy for reheating (on an annual basis) is from site recovered energy or on-site renewable energy. [ASHRAE 90.1:6.5.3.5]

  E 503.5.6.5 Fractional Horsepower Fan Motors. Motors for fans that are [1] ⁄ 12 hp (62.1 W) or more and less than 1 hp (0.7 kW) shall be electronically-commutated motors or shall have a motor efficiency of not less than 70 percent where rated in accordance with DOE 10 CFR 431. These motors

  shall also have the means to adjust motor speed for either balancing or remote control. Belt-driven fans shall be permitted to use sheave adjustments for airflow balancing in lieu of a varying motor speed.

  Exceptions:

  (1) Motors in the airstream within fan coils and terminal units that operate when providing heating to the space served.

  (2) Motors installed in space conditioning equipment certified in accordance with Section E

  503.4 through Section E 503.4.4.1.

  (3) Motors shown in Table E 503.5.6.5(1) or Table E 503.5.6.5(2). [ASHRAE 90.1:6.5.3.6]

  E 503.5.6.6 Low Power Fans. Fans that are not

• CALGreen § 6.1507 High relevance — show source text

  LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
  2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
  Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
  where× = Condenser DT + LIFT
  COPadj = Kadj * COPstd|

  A6.207.1.2 Controls for heat pumps with supplementary electric resistance heaters. Heat pumps with supplementary electric resistance heaters shall have controls:

  A6.207.1.2.1 That prevent supplementary heater operation when the heating load can be met by the heat pump alone; and

• CALGreen § 90.1 High relevance — show source text

  trols capable of and configured to automatically restart and temporarily operate the mechanical cooling system as required to maintain zone temperatures below an adjustable cooling setpoint of not less than 5°F (3°C) above the occupied cooling setpoint or to prevent high space humidity levels.

  Exception: Radiant heating systems capable of and configured with a setback heating setpoint at not less than 4°F (2°C) below the occupied heating setpoint. [ASHRAE 90.1:6.4.3.3.2] E 503.4.6.3.3 Optimum Start Controls. Individual heating and cooling systems with setback controls and DDC shall have optimum start controls. The control algorithm shall, as a minimum, be a function of the difference between space temperature and occupied set point, the outdoor temperature, and the amount of time prior to scheduled occupancy. Mass radiant floor slab systems shall incorporate floor temperature into the optimum start algorithm.

  Exception: Residential spaces are not required to have optimum start controls. [ASHRAE 90.1:6.4.3.3.3] E 503.4.6.3.4 Zone Isolation. HVAC systems serving zones that are intended to operate or be occupied nonsimultaneously shall be divided into isolation areas. Zones shall be permitted to be grouped into a single isolation area provided it does not exceed 25 000 square feet (2322.6 m [2] ) of conditioned floor area and does not include more than one floor. Each isolation area shall be equipped with isolation devices capable of and configured to automatically shut off the supply of conditioned air and outdoor air to and exhaust air from the area. Each isolation area shall be controlled independently by a device meeting the requirements of Section E 503.4.6.3.1. For central systems and plants, controls and devices shall be provided to allow stable system and equipment operation for any length of time while serving only the smallest isolation area served by the system or plant.

  Exceptions: Isolation devices and controls are not required for the following:

  (1) Exhaust air and outdoor air connections to isolation zones where the fan system to which they connect is not more than 5000 ft [3] /min (2.3597 m [3] /s).

  (2) Exhaust airflow from a single isolation zone of less than 10 percent of the design airflow of the exhaust system to which it

  connects.

  (3) Zones intended to operate continuously or intended to be inoperative only when all other zones are inoperative. [ASHRAE 90.1:6.4.3.3.4]

  2025 CALIFORNIA MECHANICAL CODE 423

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  APPENDIX E

  E 503.4.6.3.5 Automatic Control of HVAC in Hotel/Motel Guest Rooms. Hotels and motels with more than 50 guest rooms shall be provided with automatic controls for the HVAC equipment serving each guest room capable of and configured according to the requirements in Section E 503.4.6.3.5.1. [ASHRAE 90.1:6.4.3.3.5]

• CALGreen § 403.3 High relevance — show source text

  ENERGY STAR equipment and appliances Appendix A6.1(OSHPD), A4.403.3, A5.204.1 General 4.201, 5.201, A5.201 Performance approach A4.203, A5.203 Outdoor lighting A5.203.1.1.1 Prescriptive approach Appendix A6.1(OSHPD), 203.3.1.2 Alterations to existing buildings A4.204.1, A4.204.1.2, A5.204.1,

  A5.204.1.1 Energy Efficient Steel Framing A5.213 Environmental Comfort 4.507, 5.507,

  A5.507

  Acoustical control A4.507, A5.507.5 Daylight A5.507.2 Lighting and thermal comfort controls A5.507.1

  Views A5.507.3

  Fireplaces 4.503, 5.503 Foundation Systems A4.403 Frost protected foundation systems A4.403.1

  Reduction in cement use A4.403.2 Framing, Energy Efficient Steel A5.213 Framing Techniques, Efficient A4.404, A5.404 Building systems A4.404.3 Lumber size A4.404.1

  Pre-cut materials and details A4.404.4 Wood framing A5.404.1

  Green Building Chapter 3 Mixed occupancy buildings 302 Phased projects 303 Voluntary tiers 304, 305 Voluntary measures 306

  HVAC Design, Equipment and Installation Appendix A6.1 (OSHPD), A5.207

  Indoor Air Quality And Exhaust 4.506, 5.506 Bathroom exhaust fans 4.506.1 Carbon dioxide monitoring 5.506.2 Carbon dioxide (CO 2 ) monitoring in classrooms 5.506.3

  Filters 5.504.5, A4.506.1 Outside air delivery 5.506.1 Indoor Moisture Control 4.505, 5.505.1 Concrete slab foundations 4.505.2

  2025 CALIFORNIA GREEN BUILDING STANDARDS CODE INDEX-1

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  INDEX

  Appendix A6.1 (OSHPD), Table A5.504.8.5 Covering of duct openings and protection of mechanical equipment during construction 4.504.1, 5.504.3 Environmental tobacco smoke control 5.504.7, Appendix A6.1 (OSHPD), A5.504.9 Finish material pollutant control 4.504.2, 5.504.4 Hazardous particulates and chemical pollutants A5.504.5 Indoor air quality (IAQ) during construction 5.504.1, A5.504.1 IAQ Post-construction A5.504.2 Paints and coatings 4.504.2.2, 5.504.4.3 Resilient flooring systems 4.504.4, 5.504.4.6, A4.504.2, A5.504.4.7 Thermal insulation 5.504.4.7, A4.504.3,

  A5.504.4.8

• CALGreen § 5-26 High relevance — show source text

  5-26 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  NONRESIDENTIAL MANDATORY MEASURES

  dance with this section by trained personnel with experience on projects of comparable size and complexity. For I-occupancies that are not regulated by OSHPD or for I-occupancies and L-occupancies that are not regulated by the California Energy Code Section 100.0 Scope, all requirements in Sections 5.410.2 through 5.410.2.6 shall apply.

  Note: For energy-related systems under the scope (Section 100) of the California Energy Code, including heating, ventilation, air conditioning (HVAC) systems and controls, indoor lighting systems and controls, as well as water heating systems and controls, refer to California Energy Code Section 120.8 for commissioning requirements.

  Commissioning requirements shall include:

  1. Owner’s or owner representative’s project requirements.
  2. Basis of design.
  3. Commissioning measures shown in the construction documents.
  4. Commissioning plan.
  5. Functional performance testing.
  6. Documentation and training.
  7. Commissioning report.

  Exceptions:

  1. Unconditioned warehouses of any size.

  2. Areas less than 10,000 square feet used for offices or other conditioned accessory spaces within unconditioned warehouses.

  3. Tenant improvements less than 10,000 square feet as described in Section 303.1.1.

  4. Open parking garages of any size, or open parking garage areas, of any size, within a structure.

  Note: For the purposes of this section, unconditioned shall mean a building, area or room which does not provide heating and/or air conditioning.

  Informational Note:

  1. Functional performance testing for heating, ventilation, air conditioning systems and lighting controls must be performed in compliance with the California Energy Code.

  5.410.2.1 Owner’s or Owner representative’s Project Requirements (OPR). [N] The expectations and requirements of the building appropriate to its phase shall be documented before the design phase of the project begins. This documentation shall include the following:

  1. Environmental and sustainability goals.
  2. Building sustainable goals.
  3. Indoor environmental quality requirements.
  4. Project program, including facility functions and hours of operation, and need for after hours operation.
  5. Equipment and systems expectations.
  6. Building occupant and operation and maintenance (O&M) personnel expectations.

  5.410.2.2 Basis of Design (BOD). [N] A written explanation of how the design of the building systems meets the OPR shall be completed at the design phase of the building project. The Basis of Design document shall cover the following systems:

  1. Renewable energy systems.

  2. Landscape irrigation systems.

  3. Water reuse systems.

  5.410.2.3 Commissioning plan. [N] Prior to permit issuance a commissioning plan shall be completed to document how the project will be commissioned. The commissioning plan shall include the following:

  1. General project information.
  2. Commissioning goals.
  3. Systems to be commissioned. Plans to test systems and components shall include: a. An explanation of the original design intent. b. Equipment and systems to be tested, including the extent of tests.

  c. Functions to be tested.

  d. Conditions under which the test shall be performed. e. Measurable criteria for acceptable performance. 4. Commissioning team information. 5. Commissioning process activities, schedules and responsibilities. Plans for the completion of commissioning shall be included.