Heat Pump Payback in Tumwater, WA
Is a heat pump worth it in Tumwater?
Tumwater technically pencils out, but only past the point the equipment would need replacing anyway. $5,500 is what Tumwater would pay extra to go electric rather than replace the furnace and AC with the same again. Tumwater's residents would see roughly $344 a year back in running costs, putting the payback around 16 years. Tumwater's own numbers say this pencils out only in theory, not in practice.
Checking a different city
This runs the same numbers for 3206 US cities, not just Tumwater. Look one up here.
The climate behind Tumwater's payback figure
4916 heating degree days pile up here every year, so Tumwater has a real but manageable winter; the cooling side runs to 201 cooling degree days, where summers rarely ask much of an air conditioner. Sizing runs off the design temperature, not the average day: 17.1°F here (coldest 2024 reading 10.9°F), which works out to a seasonal COP of 3.11 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Tumwater, below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. These numbers come from Olympia Airport, the closest NOAA station, 1.3 miles out.
The yearly running costs in Tumwater
Electricity use for heating alone comes out to about 4,003 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $596 a year. Tumwater's gas rate of $17.62 per Mcf, applied to the 51 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $939 a year, against 14.27¢ per kWh for electricity. Buying outright rather than at replacement time stretches payback to longer than the 15-year equipment life. Over 15 years, compared with a like-for-like replacement, the heat pump leaves you $345 behind.
The break-even point in Tumwater
This result holds unless electricity climbs above 23.1¢/kWh (it is 14.27¢ now) or gas drops below $10.91 per Mcf (now $17.62); past either point, gas becomes the cheaper fuel in Tumwater. When quotes arrive, compare the heat pump price with a like-for-like furnace and AC replacement: at $344 a year saved, a difference under $2,408 pays back within 7 years here, and under $3,440 within 10.
Electric resistance heat in Tumwater, compared
Not every home in Tumwater has gas service. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. The saving here runs about $1,218 a year, which recovers the extra $10,000 spent going electric in roughly 8.2 years.
Where Tumwater ranks in this dataset
Ranked against the other 3206 cities covered, Tumwater comes in at 844 for heating severity, 1 would be the coldest place in the dataset, and 1440 by population, where 1 is largest. That's the coldest third of the dataset, where climate does most of the work behind this figure.
What to do with this number in Tumwater
About 27,826 people live in Tumwater, 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.
Line up a few local HVAC quotes before you decide.
More on how this number was built
Every constant behind this page, the 3.11 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. Tumwater's 17.1°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.