Heat Pump Payback in Florence, SC
Florence, SC: the heat pump payback math
In Florence, the extra upfront cost technically comes back, just not before the equipment wears out. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $5,500. Lower bills claw that back: about $253 saved annually, for a payback of roughly 21.8 years. That's a technicality, not a recommendation, for anyone actually living in Florence.
Not the city you meant?
This runs the same numbers for 3206 US cities, not just Florence. Look one up here.
Florence's weather, in the numbers that matter
1979 heating degree days pile up here every year, so Florence has a mild winter by US standards; the cooling side runs to 2271 cooling degree days, where summers are hot enough that cooling matters as much as heating. 18°F is the figure equipment gets sized against here, the 99th-percentile cold snap, not an average day, with a low of 16°F in the 2024 station record. Worked through the model, that's a seasonal COP of 3.13 on the cold-climate unit fit for this climate. Mild on average, but the occasional cold snap is what sizes the equipment: at a 18°F design temperature Florence falls just under the 25°F line where a standard heat pump starts leaning on resistance backup, so the model prices a cold-climate unit to be safe. Climate figures trace to the nearest NOAA station, Florence Regional Airport, 3.6 miles from Florence.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 1,601 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $572 a year. That compares with roughly 21 Mcf a year of gas at Florence's $16.91 per-Mcf rate, about $824 a year with the old AC included, against a local electricity rate of 16.16¢/kWh. If the current system still worked and you replaced it anyway, the full cost would take longer than the 15-year equipment life to earn back; against buying a new furnace and AC regardless, the 15-year total lands $1,712 behind.
What would change Florence's answer
Gas would only overtake the heat pump in Florence if electricity rose past 58.7¢/kWh from 16.16¢, or gas fell under $4.66 per Mcf from $16.91. A useful quote test for Florence: the heat pump is worth it within a decade if it costs less than $2,530 more than replacing the furnace and AC, and within 7 years if the gap is under $1,771.
The other scenario: no gas furnace to begin with
Gas isn't universal in Florence, 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. About $714 a year comes back this way, enough that the 14-year payback clears the $10,000 premium comfortably within the equipment's life.
How Florence compares nationally
Florence lands at position 2436 out of 3206 cities on heating severity (coldest is 1), and 1000 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.
Deciding what's next in Florence, SC
Florence, South Carolina is home to about 40,923 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 Florence, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
The methodology guide walks through exactly how Florence's 3.13 seasonal COP and the rest of this page's numbers get built. Florence's 18°F design temperature is below the 25°F line, which is why a cold-climate unit is the right call here, see what that changes in the cold-climate unit guide.