Heat Pump Payback in Lemont, IL
Heat pump vs. gas furnace in Lemont, IL
Lemont is a place where a heat pump genuinely costs more to operate than the alternative. $5,500 is what Lemont would pay extra to go electric rather than replace the furnace and AC with the same again. Running costs here land $250 a year higher than the furnace it replaces, so that premium is never recovered. That's Lemont's own climate and rates talking, not a hedge or a caveat.
Checking a different city
Lemont is one of 3206 cities covered here, each run through the same model. Search another below.
Lemont's weather, in the numbers that matter
4951 heating degree days pile up here every year, so Lemont has a real but manageable winter; the cooling side runs to 1049 cooling degree days, where summers are hot enough that cooling matters as much as heating. The 99% winter design temperature here, the cold snap equipment must be sized for, not the seasonal average, is -4°F, and the coldest daily reading in the 2024 station record was -13°F. That puts the seasonal coefficient of performance at 2.6 for the recommended cold-climate unit. Lemont 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, Lewis University Airport, 6.8 miles from Lemont.
The yearly running costs in Lemont
Modelled on a typical 2000-square-foot house, the heat pump draws about 4,822 kWh a year to keep it warm, plus cooling, for a combined electric bill near $1,090 a year. Lemont's gas rate of $11.25 per Mcf, applied to the 52 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $839 a year, against 19.06¢ per kWh for electricity. Because the heat pump costs more to run here, the gap only widens with time: $9,254 behind after 15 years compared with replacing the furnace and AC like-for-like.
How sensitive Lemont's result is to prices
For the verdict in Lemont to flip, electricity would need to drop to about 13.3¢/kWh from 19.06¢, or gas climb past $16.10 per Mcf from $11.25. A utility offering a lower heat pump rate can change this. Until then, no quote price makes a heat pump pay back against gas in Lemont; the case for one here rests on comfort, cooling, or replacing electric heat instead.
Electric resistance heat in Lemont, compared
Plenty of homes in Lemont 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. Switching saves about $1,559 a year here, a heat pump moving heat rather than generating it needs far less electricity than resistance coils, so the extra $10,000 spent up front comes back in about 6.4 years.
Where Lemont ranks in this dataset
Lemont lands at position 815 out of 3206 cities on heating severity (coldest is 1), and 2072 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.
Deciding what's next in Lemont, IL
Lemont, Illinois is home to about 18,203 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 Lemont, nothing is lost by holding off until the current equipment genuinely fails.
Line up a few local HVAC quotes before you decide.
Where Lemont's figure comes from
Every constant behind this page, the 2.6 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. At a -4°F design temperature, Lemont sits in cold-climate territory; the guide to that class of unit explains why.