Cold-Climate Heat Pump vs. Gas Furnace Running Cost Calculator
Convert annual therms, furnace AFUE, and seasonal heat pump COP into delivered kilowatt-hours of heat, economic balance points, and 10-year cumulative savings.
Cold-Climate Heat Pump vs. Gas Furnace Running Cost Calculator
10-Year Cumulative Comparison
3.5%/yr tariff escalation assumptionCompare cold-climate inverter heat pump COP efficiency against 80%–96% AFUE natural gas, propane, and oil furnaces with 10-year cumulative fuel cost curves.
How to Compare Heat Pump COP Against Natural Gas, Propane & Oil AFUE
Combustion furnaces create heat by burning fuel (achieving 80% to 96% Annual Fuel Utilization Efficiency, or AFUE). Electric heat pumps do not create heat by electrical resistance—they use a vapor-compression refrigerant cycle to move existing thermal energy from outdoor air into your home. At a seasonal Coefficient of Performance (COP) of 3.2, a heat pump delivers 3.20 kWh of space heat for every 1.00 kWh of electricity consumed (320% efficiency).
Using data from the NEEP Cold Climate Air Source Heat Pump Product List and US EIA Winter Fuels Outlook, the table below compares the exact cost per 1,000,000 BTU (10 Therms / 293 kWh) of delivered space heat across all four major heating fuels:
| Heating System Type | Fuel / Tariff Rate | Seasonal Efficiency | Cost per 1 Million BTU Delivered | 850-Therm Home Annual Bill |
|---|---|---|---|---|
| Electric Baseboard / Strip Heat | $0.18 / kWh | 100% (COP 1.0) | $52.75 / MMBtu | $4,125 / yr |
| Fuel Oil Furnace (#2 Heating Oil) | $3.75 / gallon | 83% AFUE | $32.65 / MMBtu | $2,553 / yr |
| Propane (LP) Condensing Furnace | $2.65 / gallon | 92% AFUE | $31.46 / MMBtu | $2,460 / yr |
| Natural Gas Furnace (Standard) | $1.42 / therm | 80% AFUE | $17.75 / MMBtu | $1,388 / yr |
| Cold-Climate Inverter Heat Pump | $0.16 / kWh TOU | 330% (COP 3.3) | $14.21 / MMBtu | $1,111 / yr |
Three Worked Heat Pump vs. Furnace Case Studies Across US Climate Zones
To understand how local fuel prices, existing ductwork static pressure, and seasonal outdoor temperatures interact, examine these three complete residential thermodynamic calculations:
- Case Study 1 — Minneapolis / Chicago Cold-Winter Home (2,400 sq ft, 1,050 Therms/yr, 92% AFUE Gas vs. COP 2.95 ccASHP): Burning 1,050 therms at 92% AFUE delivers
1,050 × 29.307 × 0.92 = 28,310 kWhof winter space heat. At $1.35/therm, annual natural gas cost is $1,418. A cold-climate inverter heat pump achieving a seasonal COP of 2.95 requires28,310 ÷ 2.95 = 9,596 kWhof electricity. On a standard $0.16/kWh rate ($1,535/yr), running the heat pump 100% of the winter down to -10°F costs $117 more than gas—which is why configuring a Hybrid Dual-Fuel switchover at 24°F (using the heat pump above 24°F at COP 3.6 and the 92% gas furnace below 24°F) cuts the combined bill to $1,140/year while saving $180/summer on high-SEER2 air conditioning. - Case Study 2 — New Hampshire / Maine Rural Home on Fuel Oil or Propane (2,000 sq ft, 750 Gallons Oil = 1,035 Therms at 83% AFUE): At $3.75/gallon for #2 heating oil, winter heating costs $2,812/year to deliver 25,168 kWh of space heat. Replacing the oil burner with a 3-ton cold-climate heat pump (seasonal COP 2.85 at $0.21/kWh New England winter electric tariff) consumes 8,831 kWh ($1,854/year)—delivering an immediate $958/year net heating bill reduction with no dual-fuel switchover needed down to -5°F.
- Case Study 3 — Raleigh / Atlanta / Seattle Mild-Winter Home (1,900 sq ft, 520 Therms/yr, 80% AFUE Furnace vs. COP 3.75 Heat Pump): Delivering 12,191 kWh of heat with an older 80% furnace at $1.52/therm costs $790/year. Because winter temperatures rarely drop below 28°F, a variable-speed heat pump averages a seasonal COP of 3.75, consuming just 3,251 kWh of electricity at $0.14/kWh ($455/year)—saving $335/year on heating plus $210/year on summer cooling.
Critical Ductwork Check: External Static Pressure (0.50 in. w.c. Rule)
Heat pumps move roughly 380 to 450 CFM (Cubic Feet per Minute) of air per ton at lower supply-air temperatures (98°F–108°F) than combustion gas furnaces (which blast 130°F–140°F air at 320 CFM/ton). Before replacing a gas furnace with a central ducted heat pump, ask your HVAC contractor to measure Total External Static Pressure (TESP) across the air handler using a digital manometer. If existing return-air ducts are undersized (TESP above 0.70 inches of water column), enlarging the return drop and switching to a deep 4-inch or 5-inch MERV 11 pleated media filter prevents blower motor noise and preserves rated COP.
Worked Examples & Common Mistakes: Heat Pump vs. Furnace Fuel Math
Here are two worked winter heating comparisons showing how electricity-to-fuel price ratios determine annual savings (check your local utility rate for electricity, natural gas, or propane):
Delivered heat: 900 therms × 29.307 kWh/therm × 0.80 AFUE = 21,101 kWh thermal. Current gas cost: 900 × $1.45 = $1,305/yr. A cold-climate heat pump with a seasonal COP of 3.2 uses 21,101 ÷ 3.2 = 6,594 kWh of electricity, costing 6,594 × $0.16 = $1,055/yr—saving $250/yr on heating plus ~$160/yr on high-SEER2 summer cooling.
One gallon of propane contains 91,500 BTU (0.915 therms), so 850 gallons equals 778 therms costing $2,423/yr. At 85% AFUE, delivered heat is 19,380 kWh thermal. A COP 3.1 heat pump at $0.17/kWh electricity delivers that heat for just (19,380 ÷ 3.1) × $0.17 = $1,063/yr—saving $1,360 every winter.
Common Mistakes When Switching from a Gas Furnace to a Heat Pump
- Leaving Auxiliary Electric Resistance Heat Strips Unlocked Above 25°F: If a thermostat triggers 10 kW electric resistance backup strips (COP 1.0) during every morning setback recovery, winter electric bills will spike. Set heat-pump-maintains temperatures steady and lock out electric strips above 20°F–25°F.
- Not Checking Static Pressure on Existing Furnace Ductwork: Heat pumps move roughly 380–420 CFM per ton compared to 300–350 CFM for high-temp gas furnaces. Have your contractor measure external static pressure (target ≤ 0.5" w.c.) before installation.
Additional Heat Pump vs. Gas Furnace FAQs
How do I convert HSPF2 into seasonal Coefficient of Performance (COP)?
North American heat pumps list heating efficiency as HSPF2 (Heating Seasonal Performance Factor 2, measured in BTU per watt-hour). Because 1 watt-hour equals 3.412 BTU, divide the unit's HSPF2 rating by 3.412 to estimate its seasonal average COP: for example, an HSPF2 of 10.2 equals a seasonal COP of ~3.0 (10.2 ÷ 3.412 = 2.99).
Does replacing a gas furnace with a heat pump also replace my central air conditioner?
Yes—a heat pump is a reversible refrigeration cycle that provides both winter space heating and high-efficiency (16–20+ SEER2) summer central air conditioning using the same outdoor condenser and indoor coil. When comparing upfront quotes, compare the heat pump cost against the combined cost of a new furnace plus a new central AC.