For cooling systems: SEER = (seasonal cooling BTU) / (seasonal watt-hours). We estimate seasonal output from capacity x typical cooling hours.
| Year | Central AC (SEER) | Heat Pump Cool (SEER) | Heat Pump Heat (HSPF) | Gas Furnace (AFUE) | Boiler (AFUE) |
|---|---|---|---|---|---|
| Pre-1992 | - | - | - | - | - |
| 1992 | 10.0 | 10.0 | 6.8 | 78% | 80% |
| 2006 | 13.0 | 13.0 | 7.7 | 78% | 80% |
| 2015 | 14.0 (S) / 13.0 (N) | 14.0 | 8.2 | 80% | 82% |
| 2023+ | 15.0 (S) / 14.0 (N) | 15.0 (S) / 14.0 (N) | 8.8 | 80% (N) / 80% (S) | 82% |
| Energy Star | 16.0+ | 16.0+ | 9.0+ | 97%+ | 90%+ |
S = South/Southwest region, N = North region. Standards shown are federal minimums. 2023+ uses SEER2 metric (values shown are approximate SEER equivalents).
| Rating | Stands For | Applies To | What It Measures | Higher = ? |
|---|---|---|---|---|
| SEER | Seasonal Energy Efficiency Ratio | AC, Heat Pump (cooling) | Cooling BTU per watt-hour over a season | Better |
| EER | Energy Efficiency Ratio | AC, Heat Pump (cooling) | Cooling BTU per watt at 95F outdoor | Better |
| HSPF | Heating Seasonal Performance Factor | Heat Pump (heating) | Heating BTU per watt-hour over a season | Better |
| AFUE | Annual Fuel Utilization Efficiency | Furnace, Boiler | % of fuel converted to usable heat | Better |