Will a heat pump pay off in Mount Vernon, IL?
In Mount Vernon, a heat pump would cost more to run each year than what you have now. $3,500 is what Mount Vernon 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. The heat pump would cost about $104 more a year to run than the furnace it replaces — a premium with no payback. There's no spin on that: Mount Vernon's numbers say wait.
Why Mount Vernon's climate drives this number
Mount Vernon has a real but manageable winter — 3738 heating degree days a year against a 65°F base — and summers are hot enough that cooling matters as much as heating, at 1355 cooling degree days. Sizing runs off the design temperature, not the average day: 1.9°F here (record low -0.9°F), which works out to a seasonal COP of 2.75 for the cold-climate class of unit this climate calls for. Mount Vernon 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 MOUNT VERNON AIRPORT, the closest NOAA station, 3.3 miles out.
What it actually costs to run, year to year
Modelled on a typical 2000-square-foot house, the heat pump draws about 3,442 kWh a year to keep it warm, plus cooling, for a combined electric bill near $876 a year. Mount Vernon's gas rate of 11.25 per Mcf, applied to the 39 Mcf a year the furnace burns, puts its running cost near $773 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 $5,053 behind.
The other scenario: no gas furnace to begin with
Not every home in Mount Vernon 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 $1,263 a year, which recovers the extra $8,000 spent going electric in roughly 6.3 years.
Where Mount Vernon ranks in this dataset
Mount Vernon lands at position 1655 out of 3206 cities on heating severity (coldest is 1), and 2490 out of 3206 by population size (biggest is 1). That's the middle third for winter severity among the cities covered here.
Deciding what's next in Mount Vernon, IL
About 14,162 people live in Mount Vernon, Illinois, and every number on this page is what a contractor would actually work from when quoting a system here — the point isn't to replace that quote, it's to tell you whether to bother asking for one. Here, there's no cost penalty to waiting until your current furnace or AC actually needs replacing.
Ask a local HVAC contractor for a quote before committing either way.
Where Mount Vernon's figure comes from
The methodology guide walks through exactly how Mount Vernon's 2.75 seasonal COP and the rest of this page's numbers get built. Mount Vernon's 1.9°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.