Is a heat pump worth it in Boise City?
In Boise City, a heat pump would cost more to run each year than what you have now. Against a like-for-like gas furnace and AC swap, going electric costs $3,500 more up front here (already netting out a $2,000 tax credit). The heat pump would cost about $72 more a year to run than the furnace it replaces — a premium with no payback. There's no spin on that: Boise City's numbers say wait.
The climate behind Boise City's payback figure
Boise City has a real but manageable winter — 4976 heating degree days a year against a 65°F base — and summers are hot enough that cooling matters as much as heating, at 1428 cooling degree days. 7°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of 3°F on file. Worked through the model, that's a seasonal COP of 2.87 on the cold-climate unit fit for this climate. Boise City 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. Source: NOAA station BOISE AIR TERMINAL/GOWEN FD A, 2.2 miles from Boise City — the closest one on record.
The month-to-month numbers for Boise City
Modelled on a typical 2000-square-foot house, the heat pump draws about 4,390 kWh a year to keep it warm, plus cooling, for a combined electric bill near $702 a year. The gas furnace it replaces burns roughly 52 Mcf a year at 7.69 per Mcf here, for a running cost near $630 a year (electricity here runs 12.52¢/kWh). Buy it outright, not incrementally, and payback stretches to beyond the 15-year equipment life; over 15 years the net position sits $4,578 behind.
Electric resistance heat in Boise City, compared
Not every home in Boise City has gas service. Swap the comparison to resistance heat instead of gas, and Boise City's answer improves. The saving here runs about $1,107 a year, which recovers the extra $8,000 spent going electric in roughly 7.2 years.
Where Boise City ranks in this dataset
Boise City lands at position 739 out of 3206 cities on heating severity (coldest is 1), and 95 out of 3206 by population size (biggest is 1). That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step for 237,963 people in Boise City
About 237,963 people live in Boise City, Idaho, 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.
Ask a local HVAC contractor for a quote before committing either way.
More on how this number was built
Nothing above is a black box: the methodology guide shows the full arithmetic behind Boise City's 2.87 seasonal COP and payback figure. Boise City's 7°F design temperature is below the 25°F line, which is why a cold-climate unit is the right call here — see what that changes in the cold-climate unit guide.