Section 150.2 – Energy Efficiency Standards for Additions and Alterations to Existing…

2025 California Energy Code is adopted without amendment, except as follows (additions underlined, deletions struck through):

Section 150.2(b)1C is hereby amended to read:

C. 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 150.2(b)1D.ii.a). Entirely new or complete replacement space- conditioning systems shall meet the requirements of Sections 150.0(h), 150.0(i), 150.0(j)1, 150.0(j)2, 150.0(m)1 through 150.0(m)10; 150.0(m)12; 150.0(m)13, 150.1(c)7, 150.2(b)1F.ii, 150.2(b)1G, and TABLE 150.2-A. Additionally, where an entirely new or complete replacement space conditioning system includes a new or replacement air-cooled air conditioner in Climate Zones 1 through 14 and 16, it shall meet the applicable requirements of Section 150.2(b)1Fiv. Where an entirely new or complete replacement space conditioning system includes a new or replacement heat pump, it shall meet the applicable requirements of Section 150.2(b)1.F.v.

Section 150.2(b)1.F. is hereby amended to read:

F. Altered space conditioning system - mechanical cooling. Alterations which install new or replacement air-cooled air conditioners shall meet the applicable requirements of subsections i and iv. Alterations which install new or replacement heat pumps shall meet the applicable requirements of subsections i, ii, iii, and v. All other alterations to refrigerant containing components such as the compressor, condensing coil, evaporator coil, refrigerant metering device, or refrigerant piping, shall meet the applicable requirements of subsections i, ii, and iii. When a space- conditioning system is an air conditioner or heat pump that is altered by the installation or replacement of refrigerant-containing system components such as the compressor, condensing coil, evaporator coil, refrigerant metering device or refrigerant piping, the altered system shall comply with the following requirements:

   i.  All thermostats associated with the system shall be replaced with setback thermostats meeting the requirements of Section 110.2(c).

   ii.  Air-cooled air conditioners in Climate Zones 2 and 8 through 15 and airsource heat pumps in all climate zones, including but not limited to

ducted split systems, ducted package systems, small duct high velocity air systems, and mini-split systems, shall comply with subsections a and b, unless the system is of a type that cannot be verified using the specified procedures. Systems that cannot comply with the requirements of 150.2(b)1.F.ii shall comply with Section 150.2(b)1.F.iii.

pumps in all climate zones, including but not limited to ducted split systems, ducted package systems, small duct high velocity air systems, and mini-split systems, shall comply with subsections a and b, unless the system is of a type that cannot be verified using the specified procedures. Systems that cannot comply with the requirements of 150.2(b)1.F.ii shall comply with Section 150.2(b)1.F.iii.

 Exception to Section 150.2(b)1.F.ii: Entirely new or complete replacement packaged systems for which the manufacturer has verified correct

system refrigerant charge prior to shipment from the factory are not required to have refrigerant charge confirmed through field verification and diagnostic testing. The installer of these packaged systems shall certify on the Certificate of Installation that the packaged system was pre-charged at the factory and has not been altered in a way that would affect the charge. Ducted systems shall comply with minimum system airflow rate requirement in Section 150.2(b)1.F.ii.a, provided that the system is of a type that can be verified using the procedure specified in RA3.3 or an approved alternative in RA1.

  a. Minimum system airflow rate shall comply with the applicable subsection I or II below as confirmed through field verification and diagnostic

testing in accordance with the procedures specified in Reference Residential Appendix Section RA3.3 or an approved alternative procedure as specified in Section RA1.

        I.  Small duct high velocity systems shall demonstrate a minimum system airflow rate greater than or equal to 250 cfm per ton of nominal

cooling capacity; or

        II.  All other air-cooled air conditioner or air-source heat pump systems shall demonstrate a minimum system airflow rate greater than or

equal to 300 cfm per ton of nominal cooling capacity.

  Exception 1 to Section 150.2(b)1.F.ii.a: Systems unable to comply with the minimum airflow rate requirement shall demonstrate

compliance using the procedures in Section RA3.3.3.1.5; and the system's thermostat shall conform to the specifications in Section 110.12.

  Exception 2 to Section 150.2(b)1.F.ii.a: Entirely new or complete replacement space conditioning systems, as specified by Section

150.2(b)1C, without zoning dampers may comply with the minimum airflow rate by meeting the applicable requirements in Tables-150.0-B or 150.0- C as confirmed by field verification and diagnostic testing in accordance with the procedures in Reference Residential Appendix Section RA3.1.4.4 and RA3.1.4.5. The design clean-filter pressure drop requirements of Section 150.0(m)12C for the system air filter device(s) shall conform to the requirements given in Tables150.0-B and 150.0-C.

  b. The installer shall charge the system according to manufacturer’s specifications. Refrigerant charge shall be verified according to one of

the following options, as applicable.

        I. The installer and rater shall perform the standard charge verification procedure as specified in Reference Residential Appendix Section

RA3.2.2, or an approved alternative procedure as specified in Section RA1; or

II. The installer shall perform the weigh-in charging procedure as specified by Reference Residential Appendix Section RA3.2.3.1 provided the system is of a type that can be verified using the RA3.2.2 standard charge verification procedure and RA3.3 airflow rate verification procedure or approved alternatives in RA1. The ECC-Rater shall verify the charge using RA3.2.2 and RA3.3 or approved alternatives in RA1.

  Exception 1 to Section 150.2(b)1.F.ii.b: When the outdoor temperature is less than 55°F and the installer utilizes the weigh-in charging

procedure in Reference Residential Appendix Section RA3.2.3.1 to demonstrate compliance, the installer may elect to utilize the verification procedure in Reference Residential Appendix Section RA3.2.3.2. If the verification procedure in Section RA3.2.3.2 is used for compliance, the system's thermostat shall conform to the specifications in Section 110.12. Ducted systems shall comply with the minimum system airflow rate requirements in Section 150.2(b)1.F.ii.a.

   iii.  Air-cooled air conditioners in Climate Zones 2 and 8 through 15 and air-source heat pumps in all climate zones, including but not limited to

ducted split systems, ducted package systems, small duct high velocity, and mini-split systems, which are of a type that cannot comply with the requirements of 150.2(b)1.F.ii.b shall comply with subsections a and b, as applicable.

  a. The installer shall confirm the refrigerant charge using the weigh-in charging procedure specified in Reference Residential Appendix

Section RA3.2.3.1, as verified by an ECC-Rater according to the procedures specified in Reference Residential Appendix RA3.2.3.2; and

  b. Systems that utilize forced air ducts shall comply with the minimum system airflow rate requirement in Section 150.2(b)1.F.ii.a provided the

system is of a type that can be verified using the procedures in Section RA3.3 or an approved alternative procedure in Section RA1.

  Exception to Section 150.2(b)1.F.iii: Entirely new or complete replacement packaged systems for which the manufacturer has verified

correct system refrigerant charge prior to shipment from the factory are not required to have refrigerant charge confirmed through field verification and diagnostic testing. The installer of these packaged systems shall certify on the Certificate of Installation that the packaged system was pre- charged at the factory and has not been altered in a way that would affect the charge. Ducted systems shall comply with minimum system airflow rate requirement in Section 150.2(b)1.F.iii.b, provided that the system is of a type that can be verified using the procedure specified in Section RA3.3 or an approved alternative in Section RA1.

 iv. New or replacement air-cooled air conditioners in Climate Zones 1 through 14 and 16 shall meet the requirements of Section 150.2(b)1Fiva

or 150.2(b)1Fivb.

  a. Systems with existing duct distribution systems shall meet the following requirements:

        I.  In all climate zones, meet the airflow and fan efficacy requirements of Section 150.0(m)13B, 150.0(m)13C, or 150.0(m)13D;

Exception 1 to Section 150.2(b)1F.iv.a.I: Single zone central forced air systems and zonally controlled central forced air systems may demonstrate compliance with an airflow greater than or equal to 300 CFM per ton of nominal cooling capacity.

        II.  In all climate zones, meet the refrigerant charge verification requirements of Section 150.2(b)1.F.ii; and

        III.  In all climate zones, vented attics shall have insulation installed to achieve a U-factor of 0.020 or insulation installed at the ceiling level

shall result in an insulated thermal resistance of R-49 or greater for the insulation alone; luminaires not rated for insulation contact must be replaced or retrofitted with a fireproof cover that allows for insulation to be installed directly over the cover; and

    Exception 1 to Section 150.2(b)1F.iv.a.III: Dwelling units with at least R-38 existing insulation installed at the ceiling level.

    Exception 2 to Section 150.2(b)1.F.iv.a.III: Dwelling units where the alteration would directly cause the disturbance of asbestos unless

the alteration is made in conjunction with asbestos abatement.

    Exception 3 to Section 150.2(b)1.F.iv.a.III: Dwelling units with knob and tube wiring located in the vented attic.

    Exception 4 to Section 150.2(b)1F.iv.a.III: Where the accessible space in the attic is not large enough to accommodate the required R-

value, the entire accessible space shall be filled with insulation provided such installation does not violate Section 806.3 of Title 24, Part 2.5.

    Exception 5 to Section 150.2(b)1F.iv.a.III: Where the attic space above the altered dwelling unit is shared with other dwelling units and

the requirements of Section 150.2(b)1.F.iv.a.III are not triggered for the other dwelling units.

    IV.  In all climate zones, air seal all accessible areas of the ceiling plane between the attic and the conditioned space in accordance with