Furnaces
ENERGY STAR certified gas and oil furnaces, with AFUE efficiency, fuel type and the regions each model is certified for.
2,500 models · 57 brands
- Best
- 99%
- Median
- 96.1%
- Worst
- 95%
AFUE across 2,500 models that report it.
Gas furnaces are rated by annual fuel utilisation efficiency (AFUE) — the percentage of fuel energy that becomes heat in the building. A 96% AFUE furnace sends 96 cents of every fuel dollar into the ductwork; a 80% AFUE furnace loses 20 cents up the flue. Over a 20-year life, the difference in a cold climate is thousands of dollars.
Single-stage furnaces run at full capacity or off. Two-stage models run at a lower, quieter output most of the time and switch to full capacity only on the coldest days. Variable-speed (modulating) furnaces adjust output continuously to match the load, providing the most even temperature and highest efficiency.
Most efficient
Ranked by AFUE, an efficiency ratio that does not scale with size.
| Model | Brand | AFUE |
|---|---|---|
| SLP99UH090XV60C* | Lennox | 99% |
| 59MN7C060C21--20 | Carrier | 98.5% |
| SLP99UH135XV60D* | Lennox | 98.4% |
| 987MC60060C21 | Bryant | 98.3% |
| SLP99UH090XV48C* | Lennox | 98.2% |
| SLP99UH070XV36B* | Lennox | 98.1% |
| SLP99UH090XV36C* | Lennox | 98.1% |
| SLP99UH110XV60C* | Lennox | 98.1% |