Should Thornton switch to a heat pump?

Here in Thornton, the honest answer is that a heat pump raises your annual running cost. $3,500 is what Thornton 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. Running costs here land $195 a year HIGHER than the furnace it replaces, so that premium is never recovered. That's Thornton's own climate and rates talking, not a hedge or a caveat.

How cold Thornton actually gets

5528 heating degree days pile up here every year, so Thornton has a cold winter that leans hard on heating equipment; the cooling side runs to 852 cooling degree days, where summers add a moderate cooling load. The 99% winter design temperature here — the cold snap equipment must be sized for, not the seasonal average — is -5.4°F, against a record low of -20.6°F. That puts the seasonal coefficient of performance at 2.57 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Thornton sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station ERIE MUNICIPAL AIRPORT, 8.8 miles from Thornton — the closest one on record.

The month-to-month numbers for Thornton

Electricity use for heating alone comes out to about 5,447 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $1,020 a year. The gas furnace it replaces burns roughly 58 Mcf a year at 11.17 per Mcf here, for a running cost near $826 a year (electricity here runs 16.53¢/kWh). Buy it outright, not incrementally, and payback stretches to beyond the 15-year equipment life; over 15 years the net position sits $6,422 behind.

Electric resistance heat in Thornton, compared

Not every home in Thornton has gas service. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. The saving here runs about $1,476 a year, which recovers the extra $8,000 spent going electric in roughly 5.4 years.

Thornton against the rest of the country

Among 3206 cities, Thornton's winter puts it at rank 350 for severity, while its size puts it at rank 190 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.

Deciding what's next in Thornton, CO

Thornton, Colorado is home to about 146,689 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 Thornton, nothing is lost by holding off until the current equipment genuinely fails.

Line up a few local HVAC quotes before you decide.

Reading further on this page's numbers

The methodology guide walks through exactly how Thornton's 2.57 seasonal COP and the rest of this page's numbers get built. Thornton's -5.4°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.