Compare what each system really costs to run using COP vs AFUE and your local fuel prices — then see payback time after the 2026 federal $2,000 tax credit.
Get heat-pump install quotes from vetted local pros and compare against a furnace replacement.
Get local install quotes → Sponsored placeholderAFUE (Annual Fuel Utilization Efficiency) is the share of a fuel's energy a furnace turns into heat: 96% AFUE means $0.96 of every $1 of gas becomes warmth. COP (Coefficient of Performance) is how many units of heat a heat pump moves per unit of electricity — a COP of 3 is effectively 300% efficient, because the pump moves existing heat rather than burning fuel. The catch: a heat pump runs on electricity (often pricier per delivered BTU) and its COP falls as the weather gets colder, while a furnace's AFUE is constant. That tension is exactly what this calculator resolves at your prices.
For an annual heating load Q in BTU: heat-pump cost = Q ÷ (COP × 3,412) × elec$/kWh, furnace cost = Q ÷ (AFUE × 100,000) × gas$/therm. At the national defaults (electricity $0.165/kWh, gas $1.30/therm, COP 3.0, AFUE 0.95) a 50 million-BTU/yr home runs about $806/yr on a heat pump vs $684/yr on the furnace — the furnace is slightly cheaper to run until electricity gets cheaper or the COP rises.
The single number that decides it: breakevenCOP = (elec$/kWh × 100,000 × AFUE) ÷ (gas$/therm × 3,412). If your real seasonal COP beats the breakeven, the heat pump is cheaper to run. We show both side by side so you can see how much margin you have — and how a colder winter (which lowers COP) could flip it.
A heat pump's COP drops as outdoor temperature falls — a standard unit can sink toward ~1.5 around 5°F. Modern cold-climate heat pumps (CCHP) hold a usable COP far lower, and a dual-fuel / hybrid setup keeps a gas furnace as backup for the coldest hours. Use the climate selector (or lower the COP slider) to stress-test your worst months.
The federal 25C credit covers 30% of a qualifying heat pump, capped at $2,000 per year, and many state/utility rebates stack on top (editable field above). Because a heat pump both heats and cools, replacing a furnace and an air conditioner together makes the upfront premium much smaller — worth modelling if your AC is also near end of life.
It depends on your seasonal COP and your local electricity-to-gas price ratio. Compare your COP to the breakeven COP shown above — if it's higher, the heat pump wins on running cost.
Modern cold-climate heat pumps keep heating well below freezing; their COP just drops as it gets colder. A dual-fuel/hybrid system pairs one with a gas backup for the coldest hours.
The federal 25C credit returns 30% of a qualifying heat pump's cost, up to $2,000 per year. State and utility rebates can stack on top.
Furnaces often last 15–20 years; heat pumps roughly 12–15 (they also provide cooling, replacing a separate AC). Factor replacement timing into total cost of ownership.
A hybrid runs the heat pump in mild weather and switches to the gas furnace when COP drops below the breakeven — capturing most of the savings while keeping cold-snap comfort.
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