Heat Pump Payback in Derby, CT
Is a heat pump worth it in Derby?
Derby is a place where a heat pump genuinely costs more to operate than the alternative. Against a like-for-like gas furnace and AC swap, going electric costs $5,500 more up front here. Running costs here land $208 a year higher than the furnace it replaces, so that premium is never recovered. There's no spin on that: Derby's numbers say wait.
Not the city you meant?
This runs the same numbers for 3206 US cities, not just Derby. Look one up here.
The climate behind Derby's payback figure
Degree days tell the story here: Derby racks up 4517 heating degree days each year (base 65°F), and summers add a moderate cooling load, with 722 cooling degree days on the cooling side. 16.9°F is the figure equipment gets sized against here, the 99th-percentile cold snap, not an average day, with a low of 10.8°F in the 2024 station record. Worked through the model, that's a seasonal COP of 3.11 on the cold-climate unit fit for this climate. Derby 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. These numbers come from New Haven, the closest NOAA station, 11 miles out.
Derby's running-cost comparison, in dollars
A 2000-square-foot house here would pull roughly 3,678 heating kilowatt-hours annually on top of cooling, totalling about $1,279 a year on electricity. That compares with roughly 47 Mcf a year of gas at Derby's $16.83 per-Mcf rate, about $1,070 a year with the old AC included, against a local electricity rate of 29.78¢/kWh. With running costs higher every year, there is no payback at any purchase price; over 15 years, against a like-for-like replacement, a household here would end $8,622 behind.
The break-even point in Derby
The heat pump would become the cheaper option in Derby if electricity fell to 23.6¢/kWh (from 29.78¢) or gas rose above $21.25 per Mcf (from $16.83). At today's prices a cheaper quote cannot rescue the gas comparison in Derby, since there is no yearly saving to recover it from.
The other scenario: no gas furnace to begin with
Not every home in Derby has gas service. Swap the comparison to resistance heat instead of gas, and Derby's answer improves. The saving here runs about $2,406 a year, which recovers the extra $10,000 spent going electric in roughly 4.2 years.
How Derby compares nationally
Derby lands at position 1189 out of 3206 cities on heating severity (coldest is 1), and 2664 out of 3206 by population size (biggest is 1). That's the middle third for winter severity among the cities covered here.
What to do with this number in Derby
About 12,915 people live in Derby, Connecticut, and every number on this page is what a contractor would actually work from when quoting a system here, the point isn't to replace that quote, it's to tell you whether to bother asking for one. Here, there's no cost penalty to waiting until your current furnace or AC actually needs replacing.
Line up a few local HVAC quotes before you decide.
More on how this number was built
Every constant behind this page, the 3.11 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. At a 16.9°F design temperature, Derby sits in cold-climate territory; the guide to that class of unit explains why.