Is a heat pump worth it in Darby?
Darby technically pencils out, but only past the point the equipment would need replacing anyway. $3,500 is what Darby 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 $80 saved annually, for a payback of roughly 43.6 years. Darby's own numbers say this pencils out only in theory, not in practice.
The climate behind Darby's payback figure
Darby has a real but manageable winter — 3829 heating degree days a year against a 65°F base — and summers are hot enough that cooling matters as much as heating, at 1547 cooling degree days. The 99% winter design temperature here — the cold snap equipment must be sized for, not the seasonal average — is 14°F, against a record low of 10.9°F. That puts the seasonal coefficient of performance at 3.04 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Darby sits firmly in cold-climate territory, so that's the class of unit priced here. Climate figures trace to the nearest NOAA station, PHILADELPHIA INTERNATIONAL AI, 3.8 miles from Darby.
What it actually costs to run, year to year
A 2000-square-foot house here would pull roughly 3,189 heating kilowatt-hours annually on top of cooling, totalling about $935 a year on electricity. That compares with roughly 40 Mcf a year of gas at Darby's 15.04 per-Mcf rate — about $1,016 a year — against a local electricity rate of 20.75¢/kWh. Looked at as a full purchase rather than an incremental one, payback here is roughly 168.1 years, leaving the 15-year total $2,296 behind.
The other scenario: no gas furnace to begin with
Gas isn't universal in Darby — 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 $1,492 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 5.4 years.
Darby against the rest of the country
Ranked against the other 3206 cities covered, Darby comes in at 1626 for heating severity — 1 would be the coldest place in the dataset — and 3037 by population, where 1 is largest. That's the middle third for winter severity among the cities covered here.
Deciding what's next in Darby, PA
About 10,749 people live in Darby, Pennsylvania, 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
Nothing above is a black box: the methodology guide shows the full arithmetic behind Darby's 3.04 seasonal COP and payback figure. At a 14°F design temperature, Darby sits in cold-climate territory; the guide to that class of unit explains why.