Do Heat Pumps Really Work in Iowa Winters?

A heat pump is an air conditioner that runs in both directions. In winter it extracts heat energy from outdoor air — which exists even at very cold temperatures — and moves it inside using refrigerant and a compressor. Because it moves heat rather than creating it by burning fuel, a heat pump can deliver two to three units of heat for every unit of electricity it consumes.

What changed recently: variable-speed (inverter) compressors and improved refrigerant systems let cold-climate models maintain useful capacity at temperatures that would have stalled older single-speed units.

Cold-climate models are rated to maintain meaningful heating capacity around −5°F to −15°F, and Des Moines sees stretches at or below that during polar-vortex events. As temperatures fall, a heat pump's output drops and its cost-per-unit-of-heat rises. Below its balance point, it needs help.

That's why the most common configuration we install here is a dual-fuel system: a heat pump handles the bulk of the season efficiently, and a gas furnace takes over automatically during the coldest snaps. You get heat-pump economics most of the winter without betting your comfort on the coldest week of the year.

• Defrost cycles — frost on the outdoor coil is normal; the unit periodically reverses to melt it (you'll see steam). A unit that ices into a solid block has a defrost fault.
• Undersized backup heat — if the electric or gas backup was never sized for a design-day, the coldest nights expose it.
• Wrong thermostat setup — heat pumps run long, low, and steady. Aggressive setbacks that trigger auxiliary heat can erase the savings.
• Standard (non-cold-climate) units installed here — the biggest source of "heat pumps don't work in Iowa" stories. Equipment selection matters.

The picture changed in 2026 and much online advice is now out of date. The federal 25C tax credit ended for installations completed after December 31, 2025. However, MidAmerican Energy's efficiency rebates remain active for qualifying heat pumps and other high-efficiency equipment installed by participating contractors. Rebate amounts and terms change; confirm current figures with MidAmerican or ask us before you buy anything based on an incentive.