What measures apply to space-conditioning systems, ducts and VAV controls?

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

• CALGreen § 160.2 High relevance — show source text

  B. Space-conditioning zone controls. Each space-conditioning zone shall have controls designed in accordance with i or ii: i. Each space-conditioning zone shall have controls that prevent: a. Reheating; and b. Recooling; and c. Simultaneous provisions of heating and cooling to the same zone, such as mixing or simultaneous supply of air that has been previously mechanically heated and air that has been previously cooled either by cooling equipment or by economizer systems; or ii. Zones served by variable air-volume systems that are designed and controlled to reduce, to a minimum, the volume of reheated, recooled or mixed air are allowed only if the controls meet all of the following requirements: a. For each zone with direct digital controls (DDC), the volume of primary air that is reheated, recooled or mixed air supply shall not exceed the larger of: I. 50 percent of the peak primary airflow; or II. The design zone outdoor airflow rate as specified by Section 160.2(c)3. b. The volume of primary air in the deadband shall not exceed the design zone outdoor airflow rate as specified by Section 160.2(c)3. c. The first stage of heating consists of modulating the zone supply air temperature setpoint up to a maximum setpoint no higher than 95ºF while the airflow is maintained at the deadband flow rate. d. The second stage of heating consists of modulating the airflow rate from the deadband flow rate up to the heating maximum flow rate.

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  MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

  e. For each zone without DDC, the volume of primary air that is reheated, recooled or mixed air supply shall not exceed the larger of the following: I. 30 percent of the peak primary airflow; or II. The design zone outdoor airflow rate as specified by Section 160.2(c)3. Exception 1 to Section 170.2(c)4B: Zones with special pressurization relationships or cross-contamination control needs.

  Exception 2 to Section 170.2(c)4B: Zones served by space-conditioning systems in which at least 75 percent of the energy for reheating, or providing warm air in mixing systems, is provided from a site-recovered or site-solar energy

  source.

  Exception 3 to Section 170.2(c)4B: Zones in which specific humidity levels are required to satisfy exempt process loads. Computer rooms or other spaces where the only process load is from IT equipment may not use this exception. Exception 4 to Section 170.2(c)4B: Zones with a peak supply-air quantity of 300 cfm or less.

  TABLE 170.2-C—EXHAUST, RETURN, RELIEF, TRANSFER FAN POWER ALLOWANCES (WATT/CFM)	Col2	Col3	Col4	Col5	Col6	Col7
  	MULTI-ZONE VAV SYSTEMS ≤ 5,000 cfm	MULTI-ZONE VAV SYSTEMS > 5,000 and ≤ 10,000 cfm1	MULTI-ZONE VAV SYSTEMS **> 10,

• 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 § 1.4.2. High relevance — show source text

  7. Backdraft dampers. All fan systems, regardless of volumetric capacity, that exchange air between the building conditioned space and the outside of the building shall be provided with backdraft or automatic dampers to prevent unintended air leakage through the fan system when the fan system is not operating.

  8. Gravity ventilation dampers. All gravity ventilating systems that serve conditioned space shall be provided with either automatic or readily accessible, manually operated dampers in all openings to the outside except combustion inlet and outlet air openings and elevator shaft vents.

  9. Protection of insulation. Insulation shall be protected from damage, including that due to sunlight, moisture, equipment maintenance and wind, but not limited to the following: Insulation exposed to weather shall be suitable for outdoor service, e.g., protected by aluminum, sheet metal, painted canvas or plastic cover. Cellular foam insulation shall be protected as above or painted with a coating that is water retardant and provides shielding from solar radiation that can cause degradation of the material.

  10. Porous inner core flex duct. Flexible ducts having porous inner cores shall have a non-porous layer or air barrier between the inner core and the outer vapor barrier.

  11. Duct system sealing and leakage testing. When space-conditioning systems utilize forced air duct systems to supply conditioned air to an occupiable space, the ducts shall be sealed as confirmed through field verification and diagnostic testing in accordance with all applicable procedures specified in Reference Residential Appendix RA3.1, and conforming to one of the following Subsections A, B or C as applicable. Air handler airflow for calculation of duct leakage rate compliance targets shall be determined according to methods specified in Reference Residential Appendix RA3.1.4.2. A. For single-family dwellings and townhouses with the air-handling unit installed and the ducts connected directly to the air handler, the total leakage of the duct system shall not exceed 5 percent of the air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.1. B. For single-family dwellings and townhouses at the rough-in stage of construction prior to installation of the dwelling’s interior finishing: i. Air-handling unit installed. If the air-handling unit is installed and the ducts are connected directly to the air handler, the total leakage of the duct system shall not exceed 5 percent of the air handler airflow as determined utilizing the procedures in Reference Residential Appendix Sections RA3.1.4.3.2, RA3.1.4.3.2.1 and RA3.1.4.3.3. ii. Air-handling unit not yet installed. If the air-handling unit is not yet installed, the total leakage of the duct system shall not exceed 4 percent of the air handler airflow as determined utilizing the procedures in Reference Residential Appendix Sections RA3.1.4.3.2, RA3.1.4.3.2.2 and RA3.1.4.3.3.

  12. Air filtration.

  A. System types specified in Subsections i, ii, and iii shall be provided with air filters in accordance with Sections 150.0(m)12B, 150.0(m)12C, and 150.0(m)12D. System types specified in Subsection i shall also comply with Section 150.0(m)12E.

  i. Mechanical space-conditioning systems that supply air to an occupiable space through ductwork exceeding 10 feet (3 m) in length. ii. Mechanical supply-only ventilation systems and makeup air systems that provide outside air to an occupiable

  space.

• CALGreen § 110.0 High relevance — show source text

  (a) Additions. Additions shall meet either Item 1 or 2 below.

  1. Prescriptive approach. The envelope and lighting of the addition, any newly installed space-conditioning system, electrical power distribution system, or water-heating system; any addition to an outdoor lighting system; and any new sign installed in conjunction with an indoor or outdoor addition shall meet the applicable requirements of Sections 110.0 through 120.7, 120.9 through 130.5 and 140.2 through 140.9.
  2. Performance approach. A. The envelope and indoor lighting in the conditioned space of the addition, and any newly installed space-conditioning system, electrical power distribution system, or water-heating system, shall meet the applicable requirements of Sections 110.0 through 120.7, 120.9 through 130.5; and

  B. Either:

  i. The addition alone shall comply with Section 140.1; or ii. Existing plus addition plus alteration. The standard design for existing plus addition, plus alteration energy use is the combination of the existing building’s unaltered components to remain, existing building altered components that are the more efficient, in LSC, of either the existing conditions, or the requirements of Section 141.0(b)2, plus the proposed addition’s energy use meeting the requirements of Section 140.1. The proposed design energy use is the combination of the existing building’s unaltered components to remain and the altered component’s energy features, plus the proposed energy features of the addition.

  Exception 1 to Section 141.0(a): When heating, cooling or service water heating to an addition are provided by expanding existing systems, the existing systems and equipment need not comply with Sections 110.0 through 120.9 or Sections 140.4 through 140.5.

  Exception 2 to Section 141.0(a): Where an existing system with electric reheat is expanded by adding variable air volume (VAV) boxes to serve an addition, total electric reheat capacity may be expanded so that the total capacity does not exceed 150 percent of the existing installed electric heating capacity in any one permit, and the system need not comply with Section 140.4(g). Additional electric reheat capacity in excess of 150 percent of the existing installed electric heating capacity may be added subject to the requirements of Section 140.4(g).

  Exception 3 to Section 141.0(a): Duct sealing. When ducts are extended from an existing duct system to serve the addition, the existing duct system and the extended ducts shall meet the applicable requirements specified in Section 141.0(b)2D.

  Exception 4 to Section 141.0(a): Additions that increase the area of the roof by 2,000 square feet or less are not required to comply with Section 110.10.

  Exception 5 to Section 141.0(a): A gas hot water boiler system with a total system input of at least 1 MMBtu/h but no more than 10 MMBtu/h added to an existing building is not required to comply with Section 140.4(k)8.

  Exception 6 to Section 141.0(a): A gas service water-heating system with a total system input of at least 1 MMBtu/h added to an existing building is not required to comply with Section 140.5(c).

  Exception 7 to Section 141.0(a) : Section 140.4(a)2 shall not apply to new space-conditioning systems or components.

  2025 CALIFORNIA ENERGY CODE 149

• CALGreen § 120.4 High relevance — show source text

  The system is not a single package air-cooled commercial unitary air conditioner or heat pump; and 2. The cooling capacity of the system is less than 54,000 Btu/h. D. Altered duct systems. New or replacement space-conditioning system ducts installed to serve an existing building shall meet the requirements of Section 120.4 (a) through (f) and meet i, ii or iii below: i. Entirely new or complete replacement duct systems installed as part of an alteration shall be leakage tested in accordance with Section 120.4(g). This applies to replacement duct systems installed as part of an alteration that are constructed of at least 75 percent new duct material. Up to 25 percent of that alteration may consist of reused parts from the building’s existing duct system (including registers, grilles, boots, air handlers, coils, plenums and ducts) if the reused parts are accessible and can be sealed to prevent leakage. ii. If the new ducts are an extension of an existing duct system and the combined new and existing duct system meets the criteria in Subsections 1, 2, 3 and 4 below, the duct system shall be sealed to a leakage rate not to exceed 15 percent of the nominal air handler airflow rate as confirmed through acceptance testing, in accordance with the applicable procedures in Reference Nonresidential Appendix NA7.5.3:

  1. The duct system does not serve a healthcare facility;
  2. The duct system provides conditioned air to an occupiable space for a constant volume, single zone, space-conditioning system;
  3. The space-conditioning system serves less than 5,000 square feet of conditioned floor area; and
  4. The combined surface area of the ducts located outdoors or in unconditioned space is more than 25 percent of the total surface area of the entire duct system. Exception 1 to Section 141.0(b)2Dii: When it is not possible to achieve the duct leakage criteria in Section 141.0(b)2Dii, then all accessible leaks shall be sealed and verified through a visual inspection and a smoke test performed by a certified mechanical acceptance test technician utilizing the methods specified in Reference Nonresidential Appendix NA7.5.3. Exception 2 to Section 141.0(b)2Dii: Duct sealing. Existing duct systems that are extended, which are constructed insulated or sealed with asbestos are not required to comply with Subsection 141.0(b)2Dii. iii. If new ducts installed as part of an alteration are not required to comply with leakage testing specified by Section 141.0(b)2Di or 141.0(b)2Dii, then the new ducts shall meet the duct leakage testing requirements of CMC Section 603.9.2.

  E. Altered space-conditioning systems. When a space-conditioning system is altered by the installation or replacement of space-conditioning system equipment (including replacement of the air handler, outdoor condensing unit of a split system air conditioner or heat pump, or cooling or heating coil: i. For all altered units where the existing thermostat does not comply with the requirements for demand responsive controls specified in Section 110.12, the existing thermostat shall be replaced with a demand responsive thermostat that complies with Section 110.12. All newly installed space-conditioning systems requiring a thermostat shall be equipped with a demand responsive thermostat that complies with Section 110.12; and ii. The duct system that is connected to the new or replaced space-conditioning system equipment shall be sealed in accordance with Section 141.0(b)2Dii.

• CALGreen § 180.2 High relevance — show source text

  Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|

  2. Space-conditioning systems . A. Space-conditioning systems serving dwelling units. i. Entirely new or complete replacement space-conditioning systems installed as part of an alteration shall include all the system heating or cooling equipment, including but not limited to: condensing unit, cooling or heating coil, and air handler for split systems; or complete replacement of a packaged unit; plus entirely new or replacement duct system [Section 180.2(b)2Aiib]. Entirely new or complete replacement space-conditioning systems shall meet the requirements of Sections 160.2(a)1, 160.3(a)1, 160.3(b)1 through 3, 160.3(b)5, 160.3(b)6, 160.3(c)1, 170.2(c)3B and 180.2(b)2Av, and Table 180.2-C.

  ii. Altered duct systems—duct sealing: In all climate zones, when more than 25 feet of new or replacement space-conditioning system ducts are installed, the ducts shall comply with the applicable requirements of Subsections a and b below. New ducts located in unconditioned space shall meet the applicable requirements of Sections 160.3(b)5A through J and the duct insulation requirements of Table 180.2-C, and a. The altered duct system, regardless of location, shall be sealed as confirmed through field verification and diagnostic testing in accordance with all applicable procedures for duct sealing of altered existing duct systems as specified in Reference Residential Appendix RA3.1, utilizing the leakage compliance criteria specified in Subsection I or II below.

  TABLE 180.2-C—DUCT INSULATION R-VALUE	Col2	Col3
  Climate Zone	3, 5 through 7	1, 2, 4, 8 through 16
  Duct_R-_Value	R-6	R-8

  I. Entirely new or complete replacement duct system. If the new ducts form an entirely new or complete replacement duct system directly connected to the air handler, the duct system shall meet one of the following requirements: A. The total leakage of the duct system shall not exceed 12 percent of the air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.1,

  or

  B. The duct system leakage to outside shall not exceed 6 percent of the air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.4. Entirely new or complete replacement duct systems installed as part of an alteration are constructed of at least 75 percent new duct material, and up to 25 percent may consist of reused parts from the dwelling unit's existing duct system, including but not limited to registers, grilles, boots, air handler, coil, plenums and duct material, if the reused parts are accessible and can be sealed to prevent leakage. Entirely new or complete replacement duct systems shall also conform to the requirements of Sections 160.2(a)1 and 160.3(b)5L. If the air handler and ducts are located within a vented attic, the requirements of Section 180.2(b)1Bi shall also be met. II. Extension of an existing duct system.

• CALGreen § 180.2 High relevance — show source text

  See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.|1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.|

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  MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS AND REPAIRS TO EXISTING MULTIFAMILY BUILDINGS

  Exception 1 to Section 180.2(b)2Bi: Section 180.2(b)2Av does not apply to replacement of electric reheat of equivalent or lower capacity electric resistance space heaters, when natural gas is not available. Exception 2 to Section 180.2(b)2Bi: Operable wall or roof openings that have been previously installed without interlock controls are exempt from complying with Section 170.2(c)4L. Exception 3 to Section 180.2(b)2Bi: Section 170.2(c)4Ci is not applicable to systems that meet both of the following:

  1. The system is not a single package air-cooled commercial unitary air conditioner or heat pump; and
  2. The cooling capacity of the system is less than 54,000 Btu/h. ii. Altered duct systems. When new or replacement space-conditioning system ducts are installed to serve an existing building, the new ducts shall meet the requirements of Section 160.3(c)2 and meet a or b below:

  a. Reserved.

  b. Entirely new or replacement duct systems installed as part of an alteration shall be leakage-tested in accordance with Section 160.2(c)2H. Entirely new or replacement duct systems installed as part of an alteration shall be constructed of at least 75 percent new duct material, and up to 25 percent may consist of reused parts from the building's existing duct system, including registers, grilles, boots, air handlers, coils, plenums and ducts, if the reused parts are accessible and can be sealed to prevent leakage. Exception 1 to Section 180.2(b)2Biib: When it is not possible to achieve the duct leakage criteria in Section 180.2(b)2Biib, all accessible leaks shall be sealed and verified through a visual inspection and a smoke test performed by a certified mechanical acceptance test technician utilizing the methods specified in Reference Nonresidential Appendix NA7.5.3 Exception 2 to Section 180.2(b)2Biib: Duct sealing. Existing duct systems that are extended, which are constructed, insulated or sealed with asbestos, are not required to comply with Subsection 180.2(b)2Biib. c. If the new ducts are an extension of an existing duct system, the combined new and existing duct system meets the criteria in Subsections I, II and III below. The duct system shall be sealed to a leakage rate not to exceed 15 percent of the nominal air handler airflow rate as confirmed through acceptance testing, in accordance with Reference Nonresidential Appendix NA7.5.3: I. The duct system provides conditioned air to an occupiable space for a constant volume, single zone, space-conditioning system; and II. The space-conditioning system serves less than 5,000 square feet of conditioned floor area; and III. The combined surface area of the ducts located in the following spaces is more than 25 percent of the total surface area of the entire duct system:

  A. Outdoors;

• 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 § 140.4 High relevance — show source text

  C. New or replacement space-conditioning systems or components other than new or replacement space-conditioning system ducts shall meet the requirements of Section 140.4 applicable to the systems or components being altered and meet the following: i. Additional fan power allowances are available when determining the fan power budget (Fan kW budget ) as specified in Table 141.0-D. These values can be added to the fan power allowance values in Table 140.4-A and Table 140.4-B.

  2025 CALIFORNIA ENERGY CODE 151

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  NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES— ADDITIONS, ALTERATIONS AND REPAIRS

  TABLE 141.0-D—ADDITIONAL FAN POWER ALLOWANCES	Col2	Col3	Col4	Col5	Col6	Col7
  AIRFLOW	MULTI-ZONE VAV SYSTEMS1 ≤5,000 cfm	MULTI-ZONE VAV SYSTEMS1 >5,000 and ≤10,000 cfm	MULTI-ZONE VAV SYSTEMS1 >10,000 cfm	ALL OTHER FAN SYSTEMS ≤5,000 cfm	ALL OTHER FAN SYSTEMS >5,000 and ≤10,000 cfm	ALL OTHER FAN SYSTEMS >10,000 cfm
  Supply Fan System Additional Allowance	0.135	0.114	0.105	0.139	0.12	0.107
  Supply Fan System Additional Allowance in Unit with Adapter Curb	0.033	0.033	0.043	0.000	0.000	0.000
  Exhaust/Relief/Return/Transfer Fan System Additional Allowance	0.07	0.061	0.054	0.07	0.062	0.055
  Exhaust/Relief/Return/Transfer Fan System Additional Allowance in Unit with Adapter Curb	0.016	0.017	0.022	0.000	0.000	0.000
  1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) for the definition of a multi-zone VAV system.	1. See FAN SYSTEM,

• CALGreen § 150.2 High relevance — show source text

  Exception to Section 150.2(b)1Diib: Duct sealing. Existing duct systems that are extended, which are constructed, insulated or sealed with asbestos.

  c. Altered ducts and duct system components in garage spaces. When new or replacement space-conditioning ducts, air-handling units, cooling or heating coils, or plenums are located in a garage space, compliance with either I or II below is required. I. The measured system duct leakage shall be less than or equal to 6 percent of system air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.1; or II. All accessible leaks located in the garage space shall be sealed and verified through a visual inspection and a smoke test by a certified ECC-Rater utilizing the methods specified in Reference Residential Appendix RA3.1.4.3.5. E. Altered space-conditioning system—duct sealing. In all climate zones, when a space-conditioning system serving a single-family dwelling is altered by the installation or replacement of space-conditioning system equipment, including replacement of the air handler, outdoor condensing unit of a split system air conditioner or heat pump, or cooling or heating coil, the duct system that is connected to the altered space-conditioning system equipment shall be sealed, as confirmed through field verification and diagnostic testing in accordance with the applicable procedures for duct sealing of altered existing duct systems as specified in Reference Residential Appendix RA3.1, and the leakage compliance criteria specified in Subsection i, ii, or iii below. Additionally, when altered ducts, air-handling units, cooling or heating coils, or plenums are located in garage spaces, the system shall comply with Section 150.2(b)1Diic regardless of the length of any new or replacement space-conditioning ducts installed in the garage space. i. The measured duct leakage shall be equal to or less than 10 percent of system air handler airflow as determined utilizing the procedures in Reference Residential Appendix RA3.1.4.3.1; or ii. The measured duct leakage to outside shall be equal to or less than 7 percent of system air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.4; or iii. If it is not possible to meet the duct sealing requirements of either Section 150.2(b)1Ei or 150.2(b)1Eii, then all accessible leaks shall be sealed and verified through a visual inspection and a smoke test by a certified ECCRater utilizing the methods specified in Reference Residential Appendix Section RA3.1.4.3.5. Exception 1 to Section 150.2(b)1E: Duct sealing. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in the Reference Residential Appendix RA3.1. Exception 2 to Section 150.2(b)1E: Duct sealing. Duct systems with less than 40 linear feet as determined by visual inspection. Exception 3 to Section 150.2(b)1E: Duct sealing. Existing duct systems constructed, insulated or sealed with asbestos.

• CALGreen § 180.2 High relevance — show source text

  276 2025 CALIFORNIA ENERGY CODE

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  MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS AND REPAIRS TO EXISTING MULTIFAMILY BUILDINGS

  C. If it is not possible to meet the duct sealing requirements of either Section 180.2(b)2AiicI or II then all accessible leaks shall be sealed and verified through a visual inspection and a smoke test by a certified ECC-Rater utilizing the methods specified in Reference Residential Appendix RA3.1.4.3.5.

  Exception to Section 180.2(b)2AiiaII: duct sealing. Existing duct systems that are extended, which are constructed, insulated or sealed with asbestos. Exception 1 to 180.2(b)2Aii: The field verification and ECC-Provider data registry requirements of Reference Residential Appendix RA2 and RA3 are not required for multifamily dwelling units in buildings four stories and greater. The installer shall certify that diagnostic testing was performed in accordance with the applicable procedures. iii. Altered space-conditioning system—duct sealing. In all climate zones, when a space-conditioning system serving a multifamily dwelling is altered by the installation or replacement of space-conditioning system equipment, including replacement of the air handler, outdoor condensing unit of a split system air conditioner or heat pump, or cooling or heating coil, the duct system that is connected to the altered space-conditioning system equipment shall be sealed, as confirmed through field verification and diagnostic testing in accordance with the applicable procedures for duct sealing of altered existing duct systems as specified in Reference Residential Appendix RA3.1 and the leakage compliance criteria specified in Subsection a, b or c below. a. The measured duct leakage shall be equal to or less than 15 percent of air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.1; or b. The measured duct leakage to outside shall be equal to or less than 10 percent of air handler airflow as determined utilizing the procedures in Reference Residential Appendix Section RA3.1.4.3.4; or c. If it is not possible to meet the duct sealing requirements of either Section 180.2(b)2Aiiia or b, then all accessible leaks shall be sealed and verified through a visual inspection and a smoke test by a certified ECC-Rater utilizing the methods specified in Reference Residential Appendix RA3.1.4.3.5. Exception 1 to Section 180.2(b)2Aiii : duct sealing. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in Reference Residential Appendix RA3.1. Exception 2 to Section 180.2(b)2Aiii: duct sealing. Duct systems with less than 40 linear feet as determined by visual inspection. Exception 3 to Section 180.2(b)2Aiii: duct sealing. Existing duct systems constructed, insulated or sealed with asbestos.

  Exception 4 to Section 180.2(b)2Aiii: The field verification and ECC-Provider data registry requirements of Reference Residential Appendix RA2 and RA3 are not required for multifamily dwelling units in buildings four stories and greater. The installer shall certify that diagnostic testing was performed in accordance with the applicable procedures. iv. **Altered space-conditioning system mechanical cooling.

• CALGreen § 1.4.3.8. High relevance — show source text

  A supplemental heating unit may be installed in a space served directly or indirectly by a primary heating system, provided that the unit thermal capacity does not exceed 2
  kilowatts or 7,000 Btu/h and is controlled by a time-limiting device not exceeding 30 minutes.
  11. For duct and air handler location: REQ denotes location in conditioned space. When the table indicates ducts and air handlers are in conditioned space, a verification is
  required as specified by Reference Residential Appendix RA3.1.4.3.8.
  12. New dwelling units with a conditioned floor area of 500 square feet or less in Climate Zone 5 may comply with a maximum_U_-factor of 0.30.
  13. Option B meets §150.1(c)9A.
  14. Option C meets §150.1(c)9B.|1. Install the specified_R_-value with an air space present between the roofing and the roof deck, such as standard installation of concrete or clay tile.
  2._ R_-values shown for below roof deck insulation are for wood-framed construction with insulation installed between the framing members. Alternatives including insulation
  above rafters or above roof deck shall comply with the performance standards.
  3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
  results in an assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
  lation products to be less than or equal to the required maximum_U_-factor.
  4. Assembly_U_-factors for roofs can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that results in an
  assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.2.2 to determine alternative insulation products to be less than or
  equal to the required maximum_U_-factor.R-values shown represent the required insulation to meet the maximum_U_-factor with cavity insulation alone.
  5. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
  6. “Interior” denotes insulation installed on the inside surface of the wall. “Exterior” denotes insulation installed on the exterior surface of the wall.
  7. Below grade “interior” denotes insulation installed on the inside surface of the wall, and below grade “exterior” denotes insulation installed on the outside surface of the wall.
  8. HSPF2 means heating seasonal performance factor.
  9. When whole-house fans are required (REQ), only those whole-house fans that are listed in the Home Ventilating Institute Certified Products Directory may be installed.
  Compliance requires installation of one or more WHFs whose total airflow cfm is capable of meeting or exceeding a minimum 1.5 cfm/square foot of conditioned floor area as
  specified by Section 150.1(c)12.
  10. A supplemental heating unit may be installed in a space served directly or indirectly by a primary heating system, provided that the unit thermal capacity does not exceed 2
  kilowatts or 7,000 Btu/h and is controlled by a time-limiting device not exceeding 30 minutes.
  11. For duct and air handler location: REQ denotes location in conditioned space.