Should Nashua switch to a heat pump?
Nashua is a place where a heat pump genuinely costs more to operate than the alternative. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $3,500 after a $2,000 federal tax credit. Unfortunately the electric bill outweighs the gas bill it replaces by about $189 a year here, so the extra spend stays unrecovered. That's Nashua's own climate and rates talking, not a hedge or a caveat.
Nashua's weather, in the numbers that matter
5681 heating degree days pile up here every year, so Nashua has a cold winter that leans hard on heating equipment; the cooling side runs to 775 cooling degree days, where summers add a moderate cooling load. 3.9°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of -0.9°F on file. Worked through the model, that's a seasonal COP of 2.79 on the cold-climate unit fit for this climate. A cold-climate unit is the right call in Nashua — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Source: NOAA station BOIRE FIELD AIRPORT, 2.7 miles from Nashua — the closest one on record.
Nashua's running-cost comparison, in dollars
Electricity use for heating alone comes out to about 5,156 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $1,559 a year. Nashua's gas rate of 18.61 per Mcf, applied to the 59 Mcf a year the furnace burns, puts its running cost near $1,370 a year, against 26.80¢ per kWh for electricity. Looked at as a full purchase rather than an incremental one, payback here is longer than the 15-year equipment life, leaving the 15-year total $6,329 behind.
If your home heats with electric baseboard instead of gas
Not every home in Nashua has gas service. Swap the comparison to resistance heat instead of gas, and Nashua's answer improves. About $2,565 a year comes back this way, enough that the 3.1-year payback clears the $8,000 premium comfortably within the equipment's life.
Where Nashua ranks in this dataset
Ranked against the other 3206 cities covered, Nashua comes in at 325 for heating severity — 1 would be the coldest place in the dataset — and 381 by population, where 1 is largest. That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step for 91,851 people in Nashua
Nashua, New Hampshire is home to about 91,851 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 Nashua, 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
Nothing above is a black box: the methodology guide shows the full arithmetic behind Nashua's 2.79 seasonal COP and payback figure. At a 3.9°F design temperature, Nashua sits in cold-climate territory; the guide to that class of unit explains why.