Hanahan, SC: the heat pump payback math
Hanahan sits right on the fence — how long you'll own the house decides this one. $3,500 is what Hanahan 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 $258 saved annually, for a payback of roughly 13.6 years. Whether that's worth it in Hanahan depends on how many years you expect to own the place.
The climate behind Hanahan's payback figure
Degree days tell the story here: Hanahan racks up 1497 heating degree days each year (base 65°F), and summers are severe enough that cooling can dominate the annual bill, with 2554 cooling degree days on the cooling side. Sizing runs off the design temperature, not the average day: 23°F here (record low 21.9°F), which works out to a seasonal COP of 3.25 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Hanahan — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Source: NOAA station CHARLESTON AFB/INTERNATIONAL, 3.2 miles from Hanahan — the closest one on record.
What it actually costs to run, year to year
Modelled on a typical 2000-square-foot house, the heat pump draws about 1,166 kWh a year to keep it warm, plus cooling, for a combined electric bill near $540 a year. That compares with roughly 16 Mcf a year of gas at Hanahan's 16.91 per-Mcf rate — about $799 a year — against a local electricity rate of 16.16¢/kWh. Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs about 52.3 years, for a 15-year net position $372 ahead.
Electric resistance heat in Hanahan, compared
Plenty of homes in Hanahan heat with electricity alone, no gas line involved. Swap the comparison to resistance heat instead of gas, and Hanahan's answer improves. Switching saves about $607 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 13.2 years.
How Hanahan compares nationally
Hanahan lands at position 2695 out of 3206 cities on heating severity (coldest is 1), and 1784 out of 3206 by population size (biggest is 1). That's the mildest third of cities covered, where utility rates carry more of the answer than climate does.
What to do with this number in Hanahan
About 21,983 people live in Hanahan, South Carolina, 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 Hanahan's 3.25 seasonal COP and payback figure. At a 23°F design temperature, Hanahan sits in cold-climate territory; the guide to that class of unit explains why.