Heat Pump Payback in North Charleston, SC
Is a heat pump worth it in North Charleston?
North Charleston technically pencils out, but only past the point the equipment would need replacing anyway. $5,500 is what North Charleston would pay extra to go electric rather than replace the furnace and AC with the same again. North Charleston's residents would see roughly $258 a year back in running costs, putting the payback around 21.3 years. North Charleston's own numbers say this pencils out only in theory, not in practice.
Not the city you meant?
This runs the same numbers for 3206 US cities, not just North Charleston. Look one up here.
The climate behind North Charleston's payback figure
Degree days tell the story here: North Charleston 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. The 99% winter design temperature here, the cold snap equipment must be sized for, not the seasonal average, is 23°F, and the coldest daily reading in the 2024 station record was 21.9°F. That puts the seasonal coefficient of performance at 3.25 for the recommended cold-climate unit. The average winter here is gentle, but sizing follows the cold snaps, and 23°F is below the 25°F point where a standard unit leans on resistance backup, so a cold-climate unit is what gets priced for North Charleston. These numbers come from Charleston Afb/International, the closest NOAA station, 1.9 miles out.
North Charleston's running-cost comparison, in dollars
Electricity use for heating alone comes out to about 1,166 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $540 a year. North Charleston's gas rate of $16.91 per Mcf, applied to the 16 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $799 a year, against 16.16¢ per kWh for electricity. Priced as a standalone purchase, with a working furnace ripped out early, payback would take longer than the 15-year equipment life. Measured against the like-for-like replacement instead, a household here ends 15 years $1,628 behind.
How sensitive North Charleston's result is to prices
This result holds unless electricity climbs above 775.9¢/kWh (it is 16.16¢ now) or gas drops below $0.35 per Mcf (now $16.91); past either point, gas becomes the cheaper fuel in North Charleston. When quotes arrive, compare the heat pump price with a like-for-like furnace and AC replacement: at $258 a year saved, a difference under $1,806 pays back within 7 years here, and under $2,580 within 10.
The other scenario: no gas furnace to begin with
Plenty of homes in North Charleston heat with electricity alone, no gas line involved. Swap the comparison to resistance heat instead of gas, and North Charleston's answer improves. Even against resistance heat, the running-cost gap here isn't enough to clear the $10,000 incremental cost within the equipment's 15-year life.
North Charleston against the rest of the country
Ranked against the other 3206 cities covered, North Charleston comes in at 2692 for heating severity, 1 would be the coldest place in the dataset, and 230 by population, where 1 is largest. That's the mildest third of cities covered, where utility rates carry more of the answer than climate does.
Deciding what's next in North Charleston, SC
About 126,005 people live in North Charleston, 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.
Reading further on this page's numbers
The methodology guide walks through exactly how North Charleston's 3.25 seasonal COP and the rest of this page's numbers get built. North Charleston's 23°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.