Heat Pump Payback in Mount Pleasant, SC
Will a heat pump pay off in Mount Pleasant, SC?
Mount Pleasant sits right on the fence, how long you'll own the house decides this one. Against a like-for-like gas furnace and AC swap, going electric costs $3,000 more up front here. That premium is recovered through $240 of lower running costs every year, landing the payback clock at roughly 12.5 years. It's a genuine toss-up here, Mount Pleasant's numbers don't point clearly either way.
Not the city you meant?
Landed on Mount Pleasant by mistake, or want to compare it against somewhere else? Search the other 3206 cities below.
Mount Pleasant's weather, in the numbers that matter
Mount Pleasant barely has a winter to speak of, 1430 heating degree days a year against a 65°F base, and summers are hot enough that cooling matters as much as heating, at 2383 cooling degree days. The 99% winter design temperature here, the cold snap equipment must be sized for, not the seasonal average, is 33.4°F, and the coldest daily reading in the 2024 station record was 25°F. That puts the seasonal coefficient of performance at 3.2 for the recommended standard unit. Mount Pleasant's winters don't get cold enough to need the cold-climate premium, a standard unit holds up fine. Source: NOAA station Charleston, 3.9 miles from Mount Pleasant, 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 1,132 kWh a year to keep it warm, plus cooling, for a combined electric bill near $511 a year. Mount Pleasant's gas rate of $16.91 per Mcf, applied to the 15 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $751 a year, against 16.16¢ 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 $596 ahead.
How sensitive Mount Pleasant's result is to prices
Gas would only overtake the heat pump in Mount Pleasant if electricity rose past 335.8¢/kWh from 16.16¢, or gas fell under $0.81 per Mcf from $16.91. A useful quote test for Mount Pleasant: the heat pump is worth it within a decade if it costs less than $2,400 more than replacing the furnace and AC, and within 7 years if the gap is under $1,680.
The other scenario: no gas furnace to begin with
Gas isn't universal in Mount Pleasant, many houses run on electric heat already. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. The saving here runs about $573 a year, which recovers the extra $7,500 spent going electric in roughly 13.1 years.
Mount Pleasant against the rest of the country
Ranked against the other 3206 cities covered, Mount Pleasant comes in at 2714 for heating severity, 1 would be the coldest place in the dataset, and 361 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.
What to do with this number in Mount Pleasant
Mount Pleasant, South Carolina is home to about 95,604 people, and the figures above are the same ones a local HVAC contractor uses to size and quote a system, this site doesn't guess where a real quote would land, it just tells you whether it's worth asking for one. In Mount Pleasant, nothing is lost by holding off until the current equipment genuinely fails.
Line up a few local HVAC quotes before you decide.
More on how this number was built
Every constant behind this page, the 3.2 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. Homes in Mount Pleasant without gas service should read the electric-resistance comparison instead, the numbers there differ from the gas case above.