California contractors in climate zones 2, and 9 through 16, will be required to do duct sealing when changing out HVAC equipment in existing residential buildings. Ducts that leak 15% (6% for newly constructed buildings or an entirely new duct system) or more must be repaired to reduce the leaks. After your contractor tests and fixes the ducts, you choose whether to have an approved third-party field verifier check to make sure the duct testing and sealing was done properly or to have your house included in a random sample where one in seven duct systems are checked. Third party field verification is performed by a certified field verification and diagnostic testing rater (HERS rater). These new requirements apply when replacing the air handler, the outdoor condensing unit of a split system air conditioner or heat pump, cooling or heating coil, or the furnace heat exchanger.
In addition to the duct sealing requirements described, when a split space conditioning system is “altered” in residential buildings in climate zones 2 and 8 through 15, contractors are required to do a refrigerant charge measurement using Commission-approved protocols. This must be verified by a certified HERS rater.
If your installation includes all new equipment and ductwork in climate zones 10 - 15, your contractor must verify the cooling coil airflow in the system is at least 350 cfm per nominal ton and the wattage for the fan (fan watt draw) is equal to or less than 0.58 watts per cfm.