100,000 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 · 941 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
20-year payback
About $2,000 more to install, saving $102 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 $9 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
190 of 941
certified units are condensing (90%+ AFUE), running about $707 a year against $810 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 FF98MV510021UPS*A
AFUE 98.1 · $17.13 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 941 certified units · 6 with a verified place to buy
| Brand & model | AFUE | Input | Fuel | $/MMBtu | Buy | |
|---|---|---|---|---|---|---|
| FUJITSU FF98MV510021UPS*A | 98.1 | 98,000 BTU | Natural Gas, Propane Gas | $17.13 | Get quotes | |
| RHEEM R98MV1005A21UPS | 98.1 | 98,000 BTU | Natural Gas, Propane Gas | $17.13 | Get quotes | |
| COLEMAN BY JOHNSON CONTROLS CP9C100C16MP13 | 97.7 | 100,000 BTU | Natural Gas, Propane Gas | $17.20 | Get quotes | |
| ECOER EVMF98M35100C5L | 97.5 | 100,000 BTU | Natural Gas, Propane Gas | $17.23 | Get quotes | |
| DAIKIN DR96TC1005DN | 97.5 | 100,000 BTU | Natural Gas, Propane Gas | $17.23 | Get quotes | |
| GOODMAN GRVT961005DN | 97.5 | 100,000 BTU | Natural Gas, Propane Gas | $17.23 | Buy | |
| CARRIER 59MN7C100C21--22 | 97.3 | 100,000 BTU | Natural Gas, Propane Gas | $17.27 | Buy | |
| THERMAL ZONE TZ97UP2V100C5SA | 97.0 | 98,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| FUJITSU FF97TV510021UPS*A | 97.0 | 98,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| DURASTAR DR97UPAW1002521S | 97.0 | 98,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| RHEEM R972V1005A21UPS | 97.0 | 98,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| BOSCH BGH97M100C5A | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Buy | |
| BOSCH BGH97M100D5A | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Buy | |
| Navien NPF700-100D5CH | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| DAIKIN DR97MC1005CN | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| DAIKIN DD97MC1005CN | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| GOODMAN GDVM971005CN | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Buy | |
| TEMPSTAR F97CTN1002122A | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| BRYANT 987TA66100C21 | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Get quotes | |
| CARRIER 59TN7A100C21--22 | 97.0 | 100,000 BTU | Natural Gas, Propane Gas | $17.32 | Buy |
Showing the top 20 by AFUE. All 941 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.