Troy, MI: the heat pump payback math
In Troy, a heat pump would cost more to run each year than what you have now. $3,500 is what Troy would pay extra to go electric rather than replace the furnace and AC with the same again, once the $2,000 federal credit is applied. Unfortunately the electric bill outweighs the gas bill it replaces by about $265 a year here, so the extra spend stays unrecovered. That's Troy's own climate and rates talking, not a hedge or a caveat.
How cold Troy actually gets
Degree days tell the story here: Troy racks up 4971 heating degree days each year (base 65°F), and summers add a moderate cooling load, with 954 cooling degree days on the cooling side. Sizing runs off the design temperature, not the average day: 5.9°F here (record low -2.4°F), which works out to a seasonal COP of 2.84 for the cold-climate class of unit this climate calls for. Troy 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. Climate figures trace to the nearest NOAA station, OAKLAND/TROY AIRPORT, 3.3 miles from Troy.
The month-to-month numbers for Troy
A 2000-square-foot house here would pull roughly 4,432 heating kilowatt-hours annually on top of cooling, totalling about $1,087 a year on electricity. The gas furnace it replaces burns roughly 52 Mcf a year at 10.92 per Mcf here, for a running cost near $822 a year (electricity here runs 20.72¢/kWh). Buy it outright, not incrementally, and payback stretches to beyond the 15-year equipment life; over 15 years the net position sits $7,480 behind.
Electric resistance heat in Troy, compared
Plenty of homes in Troy heat with electricity alone, no gas line involved. Against electric-resistance heat — baseboard or an electric furnace, both 100% efficient but still just resistance — the case for switching gets stronger here. The saving here runs about $1,777 a year, which recovers the extra $8,000 spent going electric in roughly 4.5 years.
How Troy compares nationally
Among 3206 cities, Troy's winter puts it at rank 749 for severity, while its size puts it at rank 399 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.
What to do with this number in Troy
Troy, Michigan is home to about 89,209 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 Troy, 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 Troy's 2.84 seasonal COP and the rest of this page's numbers get built. At a 5.9°F design temperature, Troy sits in cold-climate territory; the guide to that class of unit explains why.