Based on our experience, the table below highlights our recommendations for heat pump system types for the various climate zones in the U.S. It also provides the efficiency specifications we used in modeling the heat pump system performance. These systems balance the trade-offs between annual heating costs, installation costs, and maximizing the greenhouse gas (GHG) emission benefits of heat pumps vs. gas heating.
| Heat Pump System | Specifications | Climate Zones | Comments |
|---|---|---|---|
| T1ES – Tier 1 heat pump (HP) with electric strip backup heating | Energy Star minimum efficiency requirements: HSPF2 7.8+, SEER2 15.2+; changeover temperature to electric strip of 15 F. | 2 or 3 | A backup furnace is not required for zones 2 and 3. |
| T2ES – Tier 2 HP with electric strip backup heating | Energy Star “most efficient” requirements: HSPF2 8.1+, SEER2 16.9+; changeover temperature to electric strip of 15 F. | 2, 3, or 4 | Tier 2 is a slightly more efficient HP than Tier 1, with slightly higher initial cost. For zone 4, we recommend also comparing T2GF and CCES. |
| T1GF – Tier 1 HP with gas furnace backup heating | See Tier 1 specs above; we recommend a changeover temperature to the gas furnace of 30 F. | 4 or 5 | For zones 4 and 5, having a backup furnace will reduce the annual heating costs slightly, and will also reduce the initial costs compared to CCES. |
| T2GF – Tier 2 HP with gas furnace backup heating | See Tier 2 specs above; we recommend a changeover temperature to the gas furnace of 30 F. | 4, 5, or 6 | This system will have slightly lower heating costs than T1GF, with slightly higher initial cost. |
| CCES – Cold-climate, ducted whole house HP with electric strip supplemental heating | Variable-speed compressor, SEER2 19.5, HSPF2 8.5; changeover temperature to electric strip of -5 F. | 4 or 5 | This system will have similar heating costs compared to T2GF, with higher initial costs. |
| CCGFX – Cold-climate whole house with gas furnace supplemental heating | See cold-climate specs above; changeover temperature to gas furnace of 15 F. | 6 or 7 | This system will have similar heating costs to the T2GF system, with greater GHG emission benefits. We recommend this system only for existing homes. |
| CCGF – Cold climate whole house with gas furnace supplemental heating | Same cold-climate specs as for CCGFX above (SEER2 19.5, HSPF2 8.5); but for new homes, we recommend a changeover temperature of 5 degrees F rather than 15 F, to maximize the GHG reduction benefits. | 6 or 7 | The gas furnace backup will reduce heating costs compared to CCES for zone 6. We recommend this system for new homes. (We do not recommend CCES or CCMSES for zone 7.) |
| CCMSES – Energy Star very high efficiency cold climate ducted or mini-split system, with electric supplemental heating | SEER2 21.8, HSPF2 9.8; changeover temperature of -10 F. | 5 or 6 | This system will have lower heating costs than CCES, with slightly higher initial costs. Because it’s more expensive, we only recommend CCMSES for new homes. |
Don’t know your climate zone? Check the Department of Energy’s regional map below.
(Enter your zip code in the search, then click anywhere on the map.)