120,000 BTU furnaces
Every certified furnace at this input rating, gas and oil, ranked by AFUE — the share of fuel that becomes heat in the house.
Data current as of July 12, 2026 · 661 certified units · source AHRI + ENERGY STAR
Which efficiency tier is worth buying at this size?
Furnace installed cost tracks the efficiency tier, not the size — so the decision at any input rating is which tier to buy, and there are two steps. Running costs below come from the certified units at this size over a 40 MMBtu season, the default our operating-cost calculator uses.
Step 1 · 80% → condensing
16-year payback
About $2,000 more to install, saving $122 a year in gas. Inside the life of a furnace — this step is worth taking.
Step 2 · condensing → modulating
Never
Another $2,750 to install for $12 a year. The gas saving is nearly nothing because the first step already captured it — buy this tier for quiet, even heat and better humidity control, not for the bill.
At this size
173 of 661
certified units are condensing (90%+ AFUE), running about $707 a year against $830 for the 80% band.
Install bands are US national typical for a like-for-like swap, compiled 2026-07-16; a condensing furnace also needs new PVC venting and a condensate drain, which is part of why the step costs what it does. Gas cost per MMBtu is computed from certified AFUE and EIA average prices — see our methodology.
Highest AFUE in this group
FUJITSU FF98MV511524UPS*A
AFUE 98.6 · $17.04 per MMBtu to run.
See installed costs →AFUE is the share of fuel a furnace turns into heat in your home. 96% AFUE wastes 4 cents of every dollar.
Every unit here is the same input rating, so the ranking is efficiency at a fixed size. Sizing is a heat-loss calculation, not a rule of thumb — a bigger furnace short-cycles rather than heating better.
The 20 highest-AFUE of 661 certified units · 2 with a verified place to buy
| Brand & model | AFUE | Input | Fuel | $/MMBtu | Buy | |
|---|---|---|---|---|---|---|
| FUJITSU FF98MV511524UPS*A | 98.6 | 112,000 BTU | Natural Gas, Propane Gas | $17.04 | Get quotes | |
| RHEEM R98MV1155A24UPS | 98.6 | 112,000 BTU | Natural Gas, Propane Gas | $17.04 | Get quotes | |
| LENNOX SLP99UH110XV60C* | 98.1 | 110,000 BTU | Natural Gas, Propane Gas | $17.13 | Get quotes | |
| GE NF98U110M5CR | 98.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.14 | Get quotes | |
| AIREASE A98USMV110C20S*-* | 98.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.14 | Get quotes | |
| COLEMAN BY JOHNSON CONTROLS CP9C120D20MP13 | 98.0 | 120,000 BTU | Natural Gas, Propane Gas | $17.14 | Get quotes | |
| LENNOX SLP99DF110XV60C* | 97.5 | 110,000 BTU | Natural Gas, Propane Gas | $17.23 | Get quotes | |
| CARRIER 59MN7C120C24--22 | 97.2 | 120,000 BTU | Natural Gas, Propane Gas | $17.28 | Buy | |
| THERMAL ZONE TZ97UP2V115D5SA | 97.0 | 112,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| FUJITSU FF97TV511524UPS*A | 97.0 | 112,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| DURASTAR DR97UPAW1152524S | 97.0 | 112,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| RHEEM R972V1155A24UPS | 97.0 | 112,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| LENNOX ML297DF110XV60C* | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| LENNOX ML297UH110XV60C* | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| GE NF97D110T5CR* | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| GE NF97U110T5CR* | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| KEPLER 97G2UH110CV20*-* | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| BOSCH BGH97M120D5A | 97.0 | 120,000 BTU | Natural Gas, Propane Gas | $17.32 | Buy | |
| BLUERIDGE B97UR1102V5C | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| GE NF97D110V5CR | 97.0 | 110,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes |
Showing the top 20 by AFUE. All 661 certified units in this group are filterable in the full database — we rank here rather than dump, because a table nobody can read is not a resource.
Capacity and efficiency are AHRI-certified values; $/MMBtu is computed by us from EIA energy prices — see methodology. Input rating is the fuel the burner consumes; output is lower by exactly the AFUE.