Woodstock, IL: the heat pump payback math

Here in Woodstock, the honest answer is that a heat pump raises your annual running cost. $3,500 is what Woodstock 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 $315 a year HIGHER than the furnace it replaces, so that premium is never recovered. That's Woodstock's own climate and rates talking, not a hedge or a caveat.

How cold Woodstock actually gets

Degree days tell the story here: Woodstock racks up 5492 heating degree days each year (base 65°F), and summers add a moderate cooling load, with 538 cooling degree days on the cooling side. The 99% winter design temperature here — the cold snap equipment must be sized for, not the seasonal average — is -2.4°F, against a record low of -25.1°F. That puts the seasonal coefficient of performance at 2.64 for the recommended cold-climate unit. Woodstock 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 BURLINGTON MUNICIPAL ARPT, the closest NOAA station, 27.1 miles out.

The month-to-month numbers for Woodstock

Modelled on a typical 2000-square-foot house, the heat pump draws about 5,268 kWh a year to keep it warm, plus cooling, for a combined electric bill near $1,091 a year. Woodstock's gas rate of 11.25 per Mcf, applied to the 57 Mcf a year the furnace burns, puts its running cost near $776 a year, against 19.06¢ 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 $8,226 behind.

If your home heats with electric baseboard instead of gas

Gas isn't universal in Woodstock — many houses run on electric heat already. Swap the comparison to resistance heat instead of gas, and Woodstock's answer improves. Switching saves about $1,692 a year here — a heat pump moving heat rather than generating it needs far less electricity than resistance coils — so the extra $8,000 spent up front comes back in about 4.7 years.

Woodstock against the rest of the country

Among 3206 cities, Woodstock's winter puts it at rank 385 for severity, while its size puts it at rank 1547 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 25,892 people in Woodstock

Woodstock, Illinois is home to about 25,892 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 Woodstock, nothing is lost by holding off until the current equipment genuinely fails.

Get quotes from local HVAC contractors before deciding.

Reading further on this page's numbers

Every constant behind this page — the 2.64 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. At a -2.4°F design temperature, Woodstock sits in cold-climate territory; the guide to that class of unit explains why.