Should Maple Valley switch to a heat pump?
This one's marginal in Maple Valley: it only clears if you stay long enough. 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). Maple Valley's residents would see roughly $315 a year back in running costs, putting the payback around 11.1 years. Whether that's worth it in Maple Valley depends on how many years you expect to own the place.
Why Maple Valley's climate drives this number
4187 heating degree days pile up here every year, so Maple Valley has a real but manageable winter; the cooling side runs to 354 cooling degree days, where summers add a moderate cooling load. The 99% winter design temperature here — the cold snap equipment must be sized for, not the seasonal average — is 19.9°F, against a record low of 17.1°F. That puts the seasonal coefficient of performance at 3.18 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Maple Valley sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station RENTON MUNICIPAL AIRPORT, 12.1 miles from Maple Valley — the closest one on record.
The month-to-month numbers for Maple Valley
Modelled on a typical 2000-square-foot house, the heat pump draws about 3,334 kWh a year to keep it warm, plus cooling, for a combined electric bill near $519 a year. Maple Valley's gas rate of 17.62 per Mcf, applied to the 44 Mcf a year the furnace burns, puts its running cost near $834 a year, against 14.27¢ per kWh for electricity. Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs about 42.9 years, for a 15-year net position $1,225 ahead.
Electric resistance heat in Maple Valley, compared
Plenty of homes in Maple Valley heat with electricity alone, no gas line involved. Swap the comparison to resistance heat instead of gas, and Maple Valley's answer improves. About $1,060 a year comes back this way, enough that the 7.6-year payback clears the $8,000 premium comfortably within the equipment's life.
How Maple Valley compares nationally
Maple Valley lands at position 1407 out of 3206 cities on heating severity (coldest is 1), and 1404 out of 3206 by population size (biggest is 1). That's the middle third for winter severity among the cities covered here.
Next step for 28,553 people in Maple Valley
About 28,553 people live in Maple Valley, 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.
Ask a local HVAC contractor for a quote before committing either way.
More on how this number was built
The methodology guide walks through exactly how Maple Valley's 3.18 seasonal COP and the rest of this page's numbers get built. Maple Valley's 19.9°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.