Heat Pump Payback in Durham, NC
Heat pump vs. gas furnace in Durham, NC
The payback math works in Durham on paper, past the equipment's own working life. 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 Durham.
Checking a different city
This runs the same numbers for 3206 US cities, not just Durham. Look one up here.
Durham's weather, in the numbers that matter
Degree days tell the story here: Durham racks up 2409 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 2068 cooling degree days on the cooling side. Sizing runs off the design temperature, not the average day: 18°F here (coldest 2024 reading 18°F), which works out to a seasonal COP of 3.13 for the cold-climate class of unit this climate calls for. Mild on average, but the occasional cold snap is what sizes the equipment: at a 18°F design temperature Durham 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, 8.8 miles out.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 1,949 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $554 a year. The gas furnace it replaces burns roughly 25 Mcf a year at $16.42 per Mcf here, for a running cost near $812 a year including the old AC (electricity here runs 14.93¢/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 $1,632 behind.
What would change Durham's answer
Gas would only overtake the heat pump in Durham 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 Durham: 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.
The other scenario: no gas furnace to begin with
Plenty of homes in Durham heat with electricity alone, no gas line involved. Swap the comparison to resistance heat instead of gas, and Durham's answer improves. The saving here runs about $757 a year, which recovers the extra $10,000 spent going electric in roughly 13.2 years.
Where Durham ranks in this dataset
Ranked against the other 3206 cities covered, Durham comes in at 2232 for heating severity, 1 would be the coldest place in the dataset, and 71 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 Durham
Durham, North Carolina is home to about 301,870 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 Durham, 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 3.13 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. At a 18°F design temperature, Durham sits in cold-climate territory; the guide to that class of unit explains why.