Heat pump vs. gas furnace in Great Falls, MT
Here in Great Falls, the honest answer is that a heat pump raises your annual running cost. $3,500 is what Great Falls would pay extra to go electric rather than replace the furnace and AC with the same again, once the $2,000 federal credit is applied. The heat pump would cost about $372 more a year to run than the furnace it replaces — a premium with no payback. There's no spin on that: Great Falls's numbers say wait.
Why Great Falls's climate drives this number
7144 heating degree days pile up here every year, so Great Falls has one of the harshest winters in the country; the cooling side runs to 434 cooling degree days, where summers add a moderate cooling load. Sizing runs off the design temperature, not the average day: -27.9°F here (record low -36.9°F), which works out to a seasonal COP of 2.3 for the cold-climate class of unit this climate calls for. Great Falls needs the cold-climate class of unit: past a 25°F design temperature a standard heat pump falls back on resistance backup often enough to eat the savings. These numbers come from GREAT FALLS INTERNATIONAL AIR, the closest NOAA station, 4.3 miles out.
Great Falls's running-cost comparison, in dollars
A 2000-square-foot house here would pull roughly 7,865 heating kilowatt-hours annually on top of cooling, totalling about $1,117 a year on electricity. The gas furnace it replaces burns roughly 74 Mcf a year at 8.99 per Mcf here, for a running cost near $745 a year (electricity here runs 13.56¢/kWh). Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs past the 15-year equipment life, for a 15-year net position $9,073 behind.
If your home heats with electric baseboard instead of gas
Gas isn't universal in Great Falls — many houses run on electric heat already. Against electric-resistance heat — baseboard or an electric furnace, both 100% efficient but still just resistance — the case for switching gets stronger here. Switching saves about $1,413 a year here — a heat pump moving heat rather than generating it needs far less electricity than resistance coils — so the extra $8,000 spent up front comes back in about 5.7 years.
Great Falls against the rest of the country
Ranked against the other 3206 cities covered, Great Falls comes in at 40 for heating severity — 1 would be the coldest place in the dataset — and 669 by population, where 1 is largest. That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step for 60,013 people in Great Falls
About 60,013 people live in Great Falls, Montana, and every number on this page is what a contractor would actually work from when quoting a system here — the point isn't to replace that quote, it's to tell you whether to bother asking for one. Here, there's no cost penalty to waiting until your current furnace or AC actually needs replacing.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
The methodology guide walks through exactly how Great Falls's 2.3 seasonal COP and the rest of this page's numbers get built. Great Falls's -27.9°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.