In addition to the requirements for all heat pump projects:

- new heat pumps sized to meet less than 90% of the total home heating load at an 8F outdoor design temperature, per ASHRAE 2021 Design Conditions, are eligible for partial home heat pump rebates if they are supplementing or replacing oil, propane, electric resistance, ETS or existing heat pumps, or if they are replacing natural gas as a secondary source of heating. 

-  integrated controls must be installed in homes with oil or propane backup to qualify for rebates on partial-home air-source or air-to-water heat pumps. 

- Integrated controls are not required if the backup heating system is heat pumps, electric resistance or ETS. 

- Integrated controls are not required if the heat pump meets 100% of the heating needs for a distinct zone in a home, meaning that there is no other heating equipment serving that zone with which to integrate the heat pump.

- Integrated controls are not required for partial-home ground-source heat pumps. 

- integrated controls must be set at or below these maximum switchover temperatures:

- A heat pump sized for whole home AC, but inadequate for whole home heating is eligible for a partial-home heat pump rebate. Integrated controls are required for air-source or air-to-water heat pumps, when the primary heating system uses fossil fuels. Installers must design the system to be able to meet the home's heating needs at the defined maximum switch-over temperature above, so that the new heat pump system is heating-ready.