Is a heat pump worth it in Lake St. Louis?

In Lake St. Louis, the extra upfront cost technically comes back, just not before the equipment wears out. $3,500 is what Lake St. Louis 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. Lake St. Louis's residents would see roughly $219 a year back in running costs, putting the payback around 16 years. That's a technicality, not a recommendation, for anyone actually living in Lake St. Louis.

Lake St. Louis's weather, in the numbers that matter

3990 heating degree days pile up here every year, so Lake St. Louis has a real but manageable winter; the cooling side runs to 1370 cooling degree days, where summers are hot enough that cooling matters as much as heating. Sizing runs off the design temperature, not the average day: 0°F here (record low -8°F), which works out to a seasonal COP of 2.7 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Lake St. Louis — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Climate figures trace to the nearest NOAA station, SPIRIT OF ST LOUIS AIRPORT, 11 miles from Lake St. Louis.

What it actually costs to run, year to year

Modelled on a typical 2000-square-foot house, the heat pump draws about 3,742 kWh a year to keep it warm, plus cooling, for a combined electric bill near $630 a year. That compares with roughly 42 Mcf a year of gas at Lake St. Louis's 14.94 per-Mcf rate — about $849 a year — against a local electricity rate of 12.83¢/kWh. Buy it outright, not incrementally, and payback stretches to 61.7 years; over 15 years the net position sits $220 behind.

If your home heats with electric baseboard instead of gas

Plenty of homes in Lake St. Louis heat with electricity alone, no gas line involved. Swap the comparison to resistance heat instead of gas, and Lake St. Louis's answer improves. The saving here runs about $894 a year, which recovers the extra $8,000 spent going electric in roughly 8.9 years.

How Lake St. Louis compares nationally

Among 3206 cities, Lake St. Louis's winter puts it at rank 1517 for severity, while its size puts it at rank 1999 for population — 1 in both cases being the extreme. That's the middle third for winter severity among the cities covered here.

Next step for 19,160 people in Lake St. Louis

Lake St. Louis, Missouri is home to about 19,160 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 Lake St. Louis, nothing is lost by holding off until the current equipment genuinely fails.

Ask a local HVAC contractor for a quote before committing either way.

Reading further on this page's numbers

Nothing above is a black box: the methodology guide shows the full arithmetic behind Lake St. Louis's 2.7 seasonal COP and payback figure. Lake St. Louis's 0°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.