How the comparison works
Every system has to deliver the same amount of heat to your home. What changes is how much energy it buys to do it, and what that energy costs.
- Electric resistance: heat ÷ 3,412 BTU per kWh.
- Gas furnace: heat ÷ 100,000 BTU per therm ÷ AFUE.
- Heat pump: heat ÷ 3,412 BTU per kWh ÷ seasonal COP.
Example: heating a mid-size home
40 million BTU of heat a year — roughly a 2,000 sq ft home in a mixed climate — at 17.5¢/kWh and an example $1.50 per therm, with a 95% furnace and a heat pump COP of 2.8.
| System | Energy used | Per year |
|---|---|---|
| Electric resistance | 11,723 kWh | $2,051.58 |
| Natural gas furnace | 421 therms | $631.58 |
| Heat pump | 4,187 kWh | $732.71 |
Before you switch systems
- Operating cost is only part of the picture — installation, rebates and tax credits matter too.
- In very cold climates, check a heat pump's rated performance at low temperatures.
- Insulation and air sealing reduce the heat you need, whatever system you choose.
Frequently asked questions
Is a heat pump cheaper than gas heat?
It depends on your electricity and gas prices. With electricity at 17.5¢/kWh, a heat pump with a seasonal COP of 2.8 beats a 95% gas furnace when gas costs more than about $1.74 per therm. Colder climates lower a heat pump's COP; cheaper electricity raises its advantage.
Why is electric resistance heat so expensive?
Baseboards, space heaters and electric furnaces turn one unit of electricity into one unit of heat. A heat pump moves heat from outside instead, delivering two to four units of heat per unit of electricity — and electricity usually costs more per unit of energy than gas.
What is AFUE?
Annual Fuel Utilization Efficiency is the share of a furnace's fuel that becomes heat in your home over a season. An 80% AFUE furnace loses a fifth of its gas up the flue; condensing furnaces reach 95% or more.
What is a heat pump's COP?
The coefficient of performance is the heat delivered per unit of electricity. A seasonal COP of 3 means three units of heat for every unit of electricity across the winter. It falls as outdoor temperatures drop.
How do I estimate how much heat my home needs?
The best source is last winter's bills. If you heat with gas, winter therms × furnace efficiency ÷ 10 gives the heat delivered in MMBtu. Otherwise, use the home size and climate estimate as a starting point.
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