Will a heat pump keep my house warm during a polar vortex?

For most South Side homes, a correctly sized cold-climate unit carries the load on all but the coldest hours, when a backup, an electric strip or your existing furnace, covers the gap. The key word is sized. An undersized system leans on backup far more often.

Do I have to rip out my gas furnace?

No. Many Chicago installs keep the furnace as backup in a dual-fuel setup, and the system switches to gas on the coldest days. You can also go all-electric if the heat pump and its backup are sized for your home.

Will my electric bill spike?

It depends on your rates, your home, and how cold the winter runs. Heat pumps are efficient, but you are moving heating load from gas to electricity, so compare total energy costs across both bills, not just one line.

How do I avoid a bad install?

Ask for a Manual J load calculation, which is room-by-room heat-loss math rather than a rule of thumb, and get more than one bid. Oversizing is the mistake this desk hears about most.

Heat pumps through a South Side February | Chicago Renewable Energy

I.How the units learned to handle a Chicago winter

Variable-speed compressors and better refrigerant control drove the change, letting a unit pull usable heat from very cold outdoor air. Many cold-climate models now hold rated output down to around 5 degrees Fahrenheit, and some are rated to keep producing heat near minus fifteen, per their manufacturers' spec sheets. The ENERGY STAR cold-climate list is the plain way to check whether a given model qualifies.

No unit works alone in the worst hours. Most South Side installs keep a backup, either an electric resistance strip or the existing gas furnace, for the handful of days when a polar vortex parks over the lake. The heat pump still does the bulk of the season's work, and the backup covers the tail.

II.What ComEd will help pay for

ComEd runs residential energy-efficiency rebates for air-source and ground-source heat pumps, with larger amounts for income-qualified households. The dollar figures move as the utility updates its program, so treat any number a contractor quotes as something to confirm on ComEd's own rebate page before you sign. At last public report the residential rebates ran from several hundred to a few thousand dollars depending on the equipment.

Federal help has been less steady. Tax credits for heat pumps shifted with recent federal law, and what is available in 2026 may not match what a neighbor claimed a year ago, so confirm the current rules before you count the money. Illinois is also standing up federally funded home energy rebates through the state energy office, a program still ramping at last public report.

III.The sizing mistakes installers still see

Oversizing is the most common error on the South Side. A contractor eyeballs the square footage, picks a big unit to be safe, and the result short-cycles, turning on and off too often, which wears the equipment and leaves rooms unevenly heated. The fix is a Manual J load calculation, a room-by-room heat-loss math that accounts for your actual walls, windows, and air leaks.

Old Chicago housing adds its own wrinkles. Ductwork in a 1920s bungalow may be too small for a heat pump's airflow, and a drafty two-flat can push the load higher than the brick suggests. Get more than one bid, ask each installer to show the load math, and ask how the backup is sized, because that is what you will lean on in the coldest week.

IV.Worth watching this month

1. ComEd updates its residential heat-pump rebate terms periodically on its program page, so check the current amounts before signing a contract.

2. The Illinois Home Energy Rebates rollout through the state energy office was still ramping at last public report and may open or widen application windows this winter.

3. Federal tax credits for heat pumps have changed recently, so confirm with the IRS what is actually available for the 2026 tax year before you count on it.

4. Illinois Commerce Commission dockets on ComEd's multi-year efficiency plan can shift rebate budgets, and the ICC e-docket is public to read.

5. Watch the forecast, because a sustained stretch near or below zero is the real test of whether your system's backup was sized right.

Heat pumps through a South Side February

I.How the units learned to handle a Chicago winter

II.What ComEd will help pay for

III.The sizing mistakes installers still see

IV.Worth watching this month

Questions readers have asked

Sources of record