Will a heat pump pay off in Tukwila, WA?

This one's marginal in Tukwila: it only clears if you stay long enough. $3,500 is what Tukwila 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. Lower bills claw that back: about $336 saved annually, for a payback of roughly 10.4 years. Whether that's worth it in Tukwila depends on how many years you expect to own the place.

The climate behind Tukwila's payback figure

Degree days tell the story here: Tukwila racks up 4626 heating degree days each year (base 65°F), and summers rarely ask much of an air conditioner, with 260 cooling degree days on the cooling side. 19°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of 15.1°F on file. Worked through the model, that's a seasonal COP of 3.16 on the cold-climate unit fit for this climate. Below the 25°F line where a standard machine starts leaning on resistance backup, Tukwila sits firmly in cold-climate territory, so that's the class of unit priced here. These numbers come from SEATTLE-TACOMA INTERNATIONAL, the closest NOAA station, 2.9 miles out.

The month-to-month numbers for Tukwila

Modelled on a typical 2000-square-foot house, the heat pump draws about 3,707 kWh a year to keep it warm, plus cooling, for a combined electric bill near $561 a year. The gas furnace it replaces burns roughly 48 Mcf a year at 17.62 per Mcf here, for a running cost near $897 a year (electricity here runs 14.27¢/kWh). Looked at as a full purchase rather than an incremental one, payback here is roughly 40.1 years, leaving the 15-year total $1,546 ahead.

The other scenario: no gas furnace to begin with

Not every home in Tukwila has gas service. Swap the comparison to resistance heat instead of gas, and Tukwila's answer improves. Switching saves about $1,159 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 6.9 years.

Tukwila against the rest of the country

Tukwila lands at position 1066 out of 3206 cities on heating severity (coldest is 1), and 1808 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.

Deciding what's next in Tukwila, WA

About 21,636 people live in Tukwila, Washington, 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

Every constant behind this page — the 3.16 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. Tukwila's 19°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.