Ottawa, IL: the heat pump payback math
Ottawa is a place where a heat pump genuinely costs more to operate than the alternative. 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 $192 a year here, so the extra spend stays unrecovered. There's no spin on that: Ottawa's numbers say wait.
Why Ottawa's climate drives this number
Ottawa has a real but manageable winter — 4775 heating degree days a year against a 65°F base — and summers add a moderate cooling load, at 986 cooling degree days. 2.3°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of -6.7°F on file. Worked through the model, that's a seasonal COP of 2.76 on the cold-climate unit fit for this climate. Ottawa 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 ILLINOIS VALLEY RGNL-WALTER D, the closest NOAA station, 17.1 miles out.
Ottawa's running-cost comparison, in dollars
A 2000-square-foot house here would pull roughly 4,381 heating kilowatt-hours annually on top of cooling, totalling about $995 a year on electricity. That compares with roughly 50 Mcf a year of gas at Ottawa's 11.25 per-Mcf rate — about $803 a year — against a local electricity rate of 19.06¢/kWh. 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 $6,383 behind.
If your home heats with electric baseboard instead of gas
Plenty of homes in Ottawa 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. The saving here runs about $1,553 a year, which recovers the extra $8,000 spent going electric in roughly 5.2 years.
Where Ottawa ranks in this dataset
Among 3206 cities, Ottawa's winter puts it at rank 974 for severity, while its size puts it at rank 2027 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 18,775 people in Ottawa
About 18,775 people live in Ottawa, 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.
More on how this number was built
The methodology guide walks through exactly how Ottawa's 2.76 seasonal COP and the rest of this page's numbers get built. At a 2.3°F design temperature, Ottawa sits in cold-climate territory; the guide to that class of unit explains why.