Home heat

Gas furnace or heat pump?

What each costs to run for a year. Fill in what you know; anything you leave blank uses a typical rating or United States (national average)'s average price.

Your numbers

Your state (for average prices)

Gas your furnace burned for heat last year therms

Heating only: your winter bills minus what the water heater, range and dryer use (about your summer months). Blank = 600.

Furnace efficiency (AFUE) %

On the furnace label: about 80% for older units, 90-98% for condensing ones. Blank = 95.

Heat pump rating (HSPF2) HSPF2

From the heat pump spec sheet. HSPF2 is rated for a mild test climate; use a lower number for a cold one. Blank = 7.5.

Prices blank = United States (national average) average

Natural gas price $ per therm

Electricity price $ per kWh

Your bill's price per unit, taxes and delivery charges included, is the most accurate number. Where the averages come from

Purchase prices and CO2 (optional)

Price of the gas model $

Price of the electric model $

Rebates or credits you will actually get for the electric one $

Your grid's CO2 per kWh kg CO2 per kWh

Payback is worked out only when both purchase prices are filled in. Count only rebates or credits you know you qualify for.

Fill in what you know, then Compare

Pressing Compare with every box blank shows the typical case with United States (national average)'s average prices. Then change one number at a time to see what moves the result.

Gas your furnace burned for heat last year600 therms
Furnace efficiency (AFUE)95 %
Heat pump rating (HSPF2)7.5 HSPF2

Household Ledger $1.95/month or $19.50/year, or $1.00 for one printable report Free during preview