Heat Pump Payback in Cary, NC
Should Cary switch to a heat pump?
Cary technically pencils out, but only past the point the equipment would need replacing anyway. Against a like-for-like gas furnace and AC swap, going electric costs $5,500 more up front here. Lower bills claw that back: about $258 saved annually, for a payback of roughly 21.3 years. That's a technicality, not a recommendation, for anyone actually living in Cary.
Not the city you meant?
This runs the same numbers for 3206 US cities, not just Cary. Look one up here.
How cold Cary actually gets
2409 heating degree days pile up here every year, so Cary has a mild winter by US standards; the cooling side runs to 2068 cooling degree days, where summers are hot enough that cooling matters as much as heating. The 99% winter design temperature here, the cold snap equipment must be sized for, not the seasonal average, is 18°F, and the coldest daily reading in the 2024 station record was 18°F. That puts the seasonal coefficient of performance at 3.13 for the recommended cold-climate unit. Mild on average, but the occasional cold snap is what sizes the equipment: at a 18°F design temperature Cary 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. These numbers come from Raleigh-Durham International, the closest NOAA station, 8 miles out.
What it actually costs to run, year to year
A 2000-square-foot house here would pull roughly 1,949 heating kilowatt-hours annually on top of cooling, totalling about $554 a year on electricity. Cary's gas rate of $16.42 per Mcf, applied to the 25 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $812 a year, against 14.93¢ 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 $1,632 behind.
What would change Cary's answer
Gas would only overtake the heat pump in Cary if electricity rose past 39.9¢/kWh from 14.93¢, or gas fell under $6.14 per Mcf from $16.42. A useful quote test for Cary: the heat pump is worth it within a decade if it costs less than $2,580 more than replacing the furnace and AC, and within 7 years if the gap is under $1,806.
Electric resistance heat in Cary, compared
Not every home in Cary has gas service. Swap the comparison to resistance heat instead of gas, and Cary's answer improves. About $757 a year comes back this way, enough that the 13.2-year payback clears the $10,000 premium comfortably within the equipment's life.
Where Cary ranks in this dataset
Cary lands at position 2233 out of 3206 cities on heating severity (coldest is 1), and 146 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 Cary
Cary, North Carolina is home to about 182,659 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 Cary, nothing is lost by holding off until the current equipment genuinely fails.
Ask a local HVAC contractor for a quote before committing either way.
More on how this number was built
Every constant behind this page, the 3.13 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. Cary's 18°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.