Heat Pump Residential Registered Vendor FAQ

The heating capacity of multi-zone heat pumps counts toward the home’s peak heating load, but their cost isn’t rebate-eligible.

Example: Two single-zones on the first floor and a multi-zone serving the second floor bedrooms. The heating capacity of the single-zones and multi-zone combined could count toward the peak heating load at design temperature.

There are several options. Some capacities can be found:

1. in product literature,
2. online,
3. on our list of commonly rebated heat pump capacities.

If you can’t find the capacity, we recommend asking your distributor.

Some advantages of single-zone heat pumps are 1) they provide backup for one another, 2) they provide better comfort, and 3) they cost less to operate.

1. Backup

If one single-zone heat pump needs service, the other heat pumps will continue to operate. With a multi-zone, any failure can lead to a “no heat” situation.

2. Better comfort

a. Single-zone heat pumps can more effectively dehumidify homes as a result of their ability to run longer at lower capacities.

b. Using multiple, single-zone heat pumps allows for the option to run them in different modes simultaneously (e.g., heat in one room, dry-mode in another, fan-only in a third, etc.). Multi-zone indoor units all need to operate in either heating or cooling mode simultaneously.

c. Single-zone, heat pump compressors turn off when there’s no heat needed. With multi-zone heat pumps, if any indoor unit calls for heat, hot refrigerant flows through all indoor units, even the ones not calling for heat. This is worsened by the fan that runs to sample room temperature. The result can be overheated rooms.

3. Cost less to operate.

There are three reasons that single-zone heat pumps offer lower operating costs.

a. One reason is that they are simply more efficient. Their AHRI HSPF ratings are up to 15.2 compared to just 12.8 for multi-zone systems.

b. Another reason that single-zone heat pumps cost less to operate is that they have better turndown ratios (i.e., the ratios between their highest and lowest rated capacities). This means that when heat demand is low (fall and spring) they can run continuously at slow speed rather than having to inefficiently cycle on and off View Example. Single-zone heat pumps also offer more capacity at lower temperatures compared to multi-zone heat pumps View Example.

c. The third reason that single-zone heat pumps cost less to run is that users can turn off one single-zone heat pump at a time to further avoid short cycling.

There are several types of homes that are ideal for this program. Here are a few examples:

1. New construction where heat pumps eliminate the expense of fuel tanks, boilers, chimneys, ductwork, and radiators

2. Homes heated with expensive fuels (electric baseboard, propane, kerosene) where the potential for cost savings is the greatest

3. Houses that just need one or two more heat pumps (small, well-insulated, open concept, heated by single pellet/gas stove or wall furnace)

Supplemental heat can be provided by anything except for the primary, fossil-fueled heating system: wood or pellet stoves, electric baseboard, electric radiant, or even a fossil-fuel room heater.

When paired with the indoor units shown in the CEE Residential HVAC – Air-Source Heat Pumps Product Model Listings, all the outdoor units on our list of rebate-eligible heat pumps are federal tax credit-eligible (for upgrades completed on or before 12/31/2025).

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