Somerville, NJ: the heat pump payback math
In Somerville, a heat pump would cost more to run each year than what you have now. 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. The heat pump would cost about $140 more a year to run than the furnace it replaces — a premium with no payback. That's Somerville's own climate and rates talking, not a hedge or a caveat.
Somerville's weather, in the numbers that matter
Somerville has a real but manageable winter — 4648 heating degree days a year against a 65°F base — and summers are hot enough that cooling matters as much as heating, at 1012 cooling degree days. 10°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of 1°F on file. Worked through the model, that's a seasonal COP of 2.94 on the cold-climate unit fit for this climate. Somerville needs the cold-climate class of unit: past a 25°F design temperature a standard heat pump falls back on resistance backup often enough to eat the savings. Source: NOAA station SOMERSET AIRPORT, 4.9 miles from Somerville — the closest one on record.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 4,003 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $1,133 a year. The gas furnace it replaces burns roughly 48 Mcf a year at 14.21 per Mcf here, for a running cost near $993 a year (electricity here runs 23.28¢/kWh). Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs past the 15-year equipment life, for a 15-year net position $5,594 behind.
If your home heats with electric baseboard instead of gas
Gas isn't universal in Somerville — many houses run on electric heat already. Swap the comparison to resistance heat instead of gas, and Somerville's answer improves. The saving here runs about $1,912 a year, which recovers the extra $8,000 spent going electric in roughly 4.2 years.
How Somerville compares nationally
Among 3206 cities, Somerville's winter puts it at rank 1051 for severity, while its size puts it at rank 2458 for population — 1 in both cases being the extreme. That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step for 14,428 people in Somerville
Somerville, New Jersey is home to about 14,428 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 Somerville, 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 Somerville's 2.94 seasonal COP and the rest of this page's numbers get built. Somerville's 10°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.