Fond du Lac, WI: the heat pump payback math
In Fond du Lac, 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. Unfortunately the electric bill outweighs the gas bill it replaces by about $386 a year here, so the extra spend stays unrecovered. That's Fond du Lac's own climate and rates talking, not a hedge or a caveat.
How cold Fond du Lac actually gets
Degree days tell the story here: Fond du Lac racks up 5892 heating degree days each year (base 65°F), and summers add a moderate cooling load, with 554 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 -5.1°F, against a record low of -11.9°F. That puts the seasonal coefficient of performance at 2.58 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Fond du Lac sits firmly in cold-climate territory, so that's the class of unit priced here. Climate figures trace to the nearest NOAA station, FOND DU LAC COUNTY AIRPORT, 2.5 miles from Fond du Lac.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 5,783 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $1,180 a year. Fond du Lac's gas rate of 10.74 per Mcf, applied to the 61 Mcf a year the furnace burns, puts its running cost near $795 a year, against 18.87¢ 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 $9,287 behind.
Electric resistance heat in Fond du Lac, compared
Gas isn't universal in Fond du Lac — many houses run on electric heat already. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. Switching saves about $1,770 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 4.5 years.
How Fond du Lac compares nationally
Fond du Lac lands at position 262 out of 3206 cities on heating severity (coldest is 1), and 927 out of 3206 by population size (biggest is 1). 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 Fond du Lac
Fond du Lac, Wisconsin is home to about 44,469 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 Fond du Lac, nothing is lost by holding off until the current equipment genuinely fails.
Line up a few local HVAC quotes before you decide.
Where Fond du Lac's figure comes from
The methodology guide walks through exactly how Fond du Lac's 2.58 seasonal COP and the rest of this page's numbers get built. Fond du Lac's -5.1°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.