Heat pumps used to have a reputation for giving up when the temperature dropped. That’s outdated. Today’s cold-climate models are built for winters like Chicago’s, with a few things to understand before you buy one.
How a heat pump heats in the cold
Even freezing air holds heat. A heat pump uses refrigerant to absorb that heat outdoors and release it inside. As it gets colder, there’s less heat to move and the heat pump works harder, so its output and efficiency drop. Cold-climate models use variable-speed compressors to keep up much further down the thermometer.
What “cold-climate” means
Look for heat pumps listed as cold-climate models, which are tested for heat output and efficiency at 5°F. Many keep running well below that. Chicago does have nights below zero, so the question isn’t only whether it runs, but whether it can supply all the heat the house needs on those nights.
Backup heat options
- Electric resistance strips in the air handler fill the gap on the coldest days.
- Dual fuel: a gas furnace takes over below a set outdoor temperature. Popular in Chicago when replacing an AC while keeping a working furnace.
- Ductless heat pumps paired with an existing boiler in radiator-heated homes.
Sizing and the house matter most
A heat pump sized for the home’s actual heat loss, in a house with decent insulation and air sealing, will handle far more of the winter on its own. Oversizing for cooling or undersizing for heating are the usual mistakes.
Snow and defrost
The outdoor unit frosts up and defrosts itself periodically. It should sit on a stand above typical snow depth, away from roof drip lines, so meltwater drains and the unit doesn’t ice over.
Read more on heat pump installation in Chicago, or call (312) 924-7223 for an assessment.