At This Winter's Prices a Heat Pump Needs a COP of 3.2 to Beat an 80% Gas Furnace, and 1.6 to Beat Propane
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Using EIA's October 2026 forecast for winter 2026-27, see what the same heat costs from your current fuel and from an air-source heat pump, the efficiency the heat pump needs to break even, and how long the extra cost takes to pay back.
It depends on the fuel you’re replacing
A heat pump moves heat instead of making it, so each kWh delivers 2 to 4 kWh of heat. Whether that’s cheap depends on what a kWh costs next to the fuel it replaces.
We used EIA’s October 2026 Short-Term Energy Outlook forecast for this winter (the average of its Q4 2026 and Q1 2027 residential prices): electricity 18.25¢ a kWh, natural gas $13.84 per thousand cubic feet ($1.336 a therm), propane $2.515 a gallon and heating oil $5.43 a gallon. The heating load is the average for gas-heated homes in EIA’s 2020 Residential Energy Consumption Survey, 44.9 million Btu of gas a year, which at 80% efficiency is 35.9 million Btu of heat. Here is what the heat pump saves (or costs) a year against each fuel:
| Seasonal COP | Natural gas, 80% | Propane, 80% | Heating oil, 80% | Electric resistance |
|---|---|---|---|---|
| 2.2 (federal minimum, 7.5 HSPF2) | −$273 | $361 | $902 | $1,048 |
| 2.37 (ENERGY STAR ducted, 8.1 HSPF2) | −$211 | $424 | $965 | $1,111 |
| 3.0 | −$41 | $594 | $1,135 | $1,281 |
| 3.5 | $51 | $686 | $1,226 | $1,372 |
Against propane, oil and electric resistance, even a minimum-efficiency heat pump wins clearly. Against natural gas at national-average prices it doesn’t: the heat pump needs a seasonal COP of 3.2 just to match an 80% furnace, and 3.8 to match a 95% condensing one. Gas is cheap per unit of heat this winter, at $16.70 per million Btu delivered by an 80% furnace against $22.57 from a heat pump at COP 2.37.
That doesn’t settle it for gas homes. If your air conditioner is due for replacement too, a heat pump does both jobs, and the extra cost can be close to zero. If you can disconnect gas entirely, the monthly customer charge goes away. And your own electricity-to-gas price ratio may be very different from the national average: the break-even is that ratio times 29.3 times the furnace efficiency, worked out for 20 price pairs.
How the math works
- Heat delivered:
fuel used × heat content × efficiency(EIA heat content: 100,000 Btu per therm, 91,452 per gallon of propane, 137,381 per gallon of heating oil, 3,412 per kWh) - Heat pump electricity:
heat delivered ÷ 3,412 ÷ seasonal COP - Yearly saving:
current fuel cost + fixed charges avoided − heat pump electricity cost - Break-even COP:
(electricity price × 1,000,000 ÷ 3,412) ÷ current cost per million Btu delivered
Seasonal COP is roughly HSPF2 ÷ 3.412. The federal minimum for split-system heat pumps since 2023 is 7.5 HSPF2 (COP 2.2), and ENERGY STAR asks for 8.1 for ducted systems (2.37). HSPF2 is rated for a moderate climate, so a cold climate averages lower unless you buy a cold-climate model; ENERGY STAR’s Cold Climate label requires a COP of at least 1.75 at 5°F.
The federal 30% credit for heat pumps (Section 25C) ended for equipment placed in service after December 31, 2025, so enter the extra cost after any state or utility rebate only.
Where this doesn’t apply
- Your prices differ a lot from the national average. The answer for gas homes turns on the ratio of your electricity price to your gas price. Use the per-unit totals from your own bills.
- Very cold climates without a cold-climate unit. Backup resistance heat on the coldest days pulls the seasonal COP down. Lower the COP rather than assuming the rated HSPF2.
- Heating load estimates. Fuel bills include water heating and cooking. Subtract a summer month’s usage from each winter month to isolate heating.
- Cooling. A heat pump also cools, usually more efficiently than an old central air unit. The calculator only counts heating.
- Ductwork and electrical upgrades. A home without ducts, or one that needs a panel upgrade, pays for that work on top of the heat pump. Get it in the quote before comparing.
What to actually do
- Pull a year of bills and work out your heating-only use and your all-in price per unit.
- Enter your electricity price and the HSPF2 of the model you’re quoted, divided by 3.412.
- If you heat with propane, oil or electric resistance, the running-cost case is usually strong; focus on the installed price.
- If you heat with gas, compare your COP with the break-even. If it’s close, the deciding factors are whether you need new air conditioning anyway and whether you’d drop gas service.
- Ask installers for the cold-climate performance (COP at 5°F), not only the HSPF2, if your winters go well below freezing.