Heat Pump Payback in Fairfax, VA
Should Fairfax switch to a heat pump?
In Fairfax, the extra upfront cost technically comes back, just not before the equipment wears out. $5,500 is what Fairfax would pay extra to go electric rather than replace the furnace and AC with the same again. Fairfax's residents would see roughly $224 a year back in running costs, putting the payback around 24.5 years. That's a technicality, not a recommendation, for anyone actually living in Fairfax.
Checking a different city
Fairfax is one of 3206 cities covered here, each run through the same model. Search another below.
How cold Fairfax actually gets
Degree days tell the story here: Fairfax racks up 3678 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1567 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 8.1°F, and the coldest daily reading in the 2024 station record was 7°F. That puts the seasonal coefficient of performance at 2.89 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Fairfax sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station Washington Dulles Internation, 9.8 miles from Fairfax, the closest one on record.
Fairfax's running-cost comparison, in dollars
Electricity use for heating alone comes out to about 3,223 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $756 a year. That compares with roughly 38 Mcf a year of gas at Fairfax's $16.79 per-Mcf rate, about $980 a year with the old AC included, against a local electricity rate of 16.58¢/kWh. 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 $2,139 behind.
The break-even point in Fairfax
Gas would only overtake the heat pump in Fairfax if electricity rose past 25.4¢/kWh from 16.58¢, or gas fell under $10.94 per Mcf from $16.79. A useful quote test for Fairfax: the heat pump is worth it within a decade if it costs less than $2,240 more than replacing the furnace and AC, and within 7 years if the gap is under $1,568.
If your home heats with electric baseboard instead of gas
Gas isn't universal in Fairfax, many houses run on electric heat already. Swap the comparison to resistance heat instead of gas, and Fairfax's answer improves. The saving here runs about $1,125 a year, which recovers the extra $10,000 spent going electric in roughly 8.9 years.
Where Fairfax ranks in this dataset
Among 3206 cities, Fairfax's winter puts it at rank 1693 for severity, while its size puts it at rank 1523 for population, 1 in both cases being the extreme. That's the middle third for winter severity among the cities covered here.
Next step if you live in Fairfax
Fairfax, Virginia is home to about 26,340 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 Fairfax, nothing is lost by holding off until the current equipment genuinely fails.
Ask a local HVAC contractor for a quote before committing either way.
Where Fairfax's figure comes from
The methodology guide walks through exactly how Fairfax's 2.89 seasonal COP and the rest of this page's numbers get built. Fairfax's 8.1°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.