Heat pump conversion.

Why this comes up now in River Forest

Ten years ago a heat pump in a Chicago suburb was a curiosity. Two things changed. Cold-climate models now hold useful capacity down to around five below zero, and the air conditioner most River Forest houses run in July is exactly the machine a heat pump replaces. If your condenser is fifteen years old and due anyway, the question of whether to replace it with another air conditioner or with a heat pump is worth twenty minutes.

The houses here shape the answer. A 1920s brick Tudor on Lathrop has a gas furnace that is staying, ductwork that was added later, and an electrical service that was upgraded once, probably in the 1970s, to 100 amps. Those three facts decide most of what follows.

What a heat pump actually is

Your air conditioner moves heat from inside the house to outside. A heat pump does the same thing and can also reverse the flow, pulling heat out of cold outdoor air and moving it inside. It does not make heat by burning anything. It moves heat that is already there, which is why it uses far less energy per unit of warmth than a furnace or a resistance heater.

Physically it looks like a condenser. Same box in the yard, same fan, same line set to a coil on top of your furnace. The differences are inside: a reversing valve, a variable-speed compressor, and controls that talk to your furnace about who is heating the house at any given hour.

The catch is that as the outdoor temperature drops, the heat available in the air drops with it, and the unit works harder for less. Older heat pumps gave up around 30 degrees. Current cold-climate units keep going, but with less output at 0 than at 40. Which is why the next section exists.

Dual fuel, and why it is the default here

Dual fuel means a heat pump paired with a gas furnace. The heat pump handles the shoulder seasons and most of winter. When the outdoor temperature drops past a set point, the system hands off to the furnace. That set point is the changeover temperature, and it is the single most important number on a dual-fuel estimate.

Set it high, around 40, and the furnace does most of the winter heating and your gas bill barely changes. Set it low, around 15 or 20, and the heat pump carries the bulk of the season on electricity. Where it belongs depends on your gas and electric rates, how well the house holds heat, and how the specific unit performs in the cold. A contractor who has thought about your house will name a number and explain it. One who has not will leave it at the factory default.

The alternative to dual fuel is all-electric: a heat pump plus electric resistance backup strips for the coldest days. It is possible here and it eliminates the gas connection, but the backup strips draw enormous current, which brings us back to the panel.

The panel question

A heat pump needs its own 240-volt circuit, typically 30 to 50 amps. Electric backup strips need another, often 60 amps or more. If your house has a 100-amp service with a full panel, and many houses between Thatcher and Harlem do, there is no room.

Then the estimate grows by a panel upgrade, a service upgrade to 200 amps, ComEd coordination for the new service drop, and an electrical permit. That can add $3,000 to $7,500 and several weeks, and it belongs on the first page of the estimate, not in a conversation on installation day.

This is also why dual fuel wins here more often than all-electric: a heat pump on one new circuit fits many existing panels. Backup strips usually do not. The electrical panel guide covers what an upgrade involves.

Ask every contractor the same question before anything else: did you look at my panel, and does this design fit it as-is?

Reading the estimate, row by row

Line these rows up across every estimate you collect. Where two of them differ, that is where the price difference usually lives.

Outdoor unit. Full model number, tonnage, and the rated heating capacity at 5 degrees. The nameplate tonnage is a cooling number; the cold-weather capacity is the one that heats your house in January.

Indoor unit or air handler. In a dual-fuel setup, a new coil matched to the outdoor unit. In an all-electric setup, a new air handler with backup strips. Either way, matched and named.

Backup heat. Your existing furnace, or electric strips with their kilowatt rating. If it is the furnace, the estimate should confirm its blower can move the air the heat pump needs.

Electrical work. The new circuit, its amperage, and a clear statement about the panel: verified with capacity, or upgrade included, or upgrade excluded with a price. "As needed" is not an answer.

Changeover setting. A number, and whether you can adjust it.

Cold-climate ratings and sizing

Two numbers matter more than the marketing tier. HSPF2 is the heating efficiency rating, the winter counterpart to SEER2. Capacity at 5 degrees is how much heat the unit still delivers when Chicago is actually cold. A unit rated at 36,000 BTU nominal might deliver 24,000 at 5 degrees, or 18,000, depending on the model, and the difference is a warm house versus a furnace running every night.

Sizing should come from a heating load calculation, not from the tonnage of the air conditioner being removed. Air conditioners here are often sized for cooling a house with big south windows; the heating load on the same house is a different number. Ask whether the size came from a calculation.

Look for the unit on the NEEP cold-climate list or with an ENERGY STAR cold-climate designation. That is the shorthand for "tested to work when it is actually cold."

What drives the price

The outdoor unit and coil are roughly half. Variable-speed cold-climate units cost more than the single-stage air conditioner they replace, and that gap is real. The other half is the circuit, the line set, the controls that coordinate heat pump and furnace, the permit, and any panel work.

The panel is the swing factor. Two identical heat pump estimates can differ by $5,000 because one includes a service upgrade and the other assumes it away. Sort that out first and the rest of the comparison usually comes into focus.

Line set replacement is the second common gap. Heat pumps run higher pressures and different oils than the 1990s air conditioner did, and reusing an old line set is a decision that should be written down, not assumed.

Noise, placement and the neighbors

Heat pumps run in winter, when the windows are closed and the yard is quiet. A variable-speed unit is quieter than the air conditioner it replaces, but it runs many more hours, including at night in January. On the narrow lots north of Lake Street the condenser pad is often six feet from the neighbor's bedroom window. Ask for the sound rating in decibels and think about where the unit sits.

It also needs clearance for airflow and for defrost. In winter the outdoor coil frosts and periodically melts it off, dripping water that freezes on the pad. Units should sit on a riser above snow depth with drainage away from walks.

Rebates and financing in 2026

The federal Section 25C credit that covered heat pumps expired for equipment placed in service after December 31, 2025. If a 2026 estimate cites a federal tax credit, ask which program specifically. As of this writing, ComEd offers rebates on qualifying heat pump installations. They have been substantially larger than Nicor’s furnace rebate and are normally handled through the contractor or distributor; check ComEd for the current amount. Some manufacturers run seasonal promotions on cold-climate lines. Ask which incentives are applied, whether the price shown is before or after, and who files the paperwork.

On financing: compare installed cash prices. Promotional financing can carry a dealer fee folded into the number. Ask for the cash price beside the monthly payment. The financing page has the longer version.

Consider the operating cost honestly too. A heat pump shifts spending from gas to electricity. With ComEd rates and Nicor rates where they are, a well-set dual-fuel system usually lowers the total, but the size of the saving depends on the changeover point and how tight the house is. Ask the contractor to show the estimate of annual operating cost, and ask what assumptions are in it.

Red flags

• No mention of the electrical panel anywhere on the estimate.
• Nameplate tonnage with no cold-weather capacity figure.
• Changeover temperature not stated, or "we set it in the field."
• A federal tax credit cited without a program name.
• Line set reuse assumed silently.
• An all-electric design with backup strips on a 100-amp service and no upgrade line.

Questions to ask

• Did you look at my panel, and does this design fit it as-is?
• What is the rated heating capacity at 5 degrees, and where did my heating load number come from?
• What changeover temperature are you proposing for my house, and why?
• Is the coil matched to the outdoor unit, and is the line set new?
• What is the sound rating, and where exactly does the unit sit?
• Which rebates apply, is the price before or after them, and who files?
• What is the labor warranty, in years, separate from parts?

The short list

Panel first. Then capacity at 5 degrees, changeover temperature, matched coil and new line set, and the two warranty terms in years. If those six things are on the page, you can compare two heat pump estimates in ten minutes. If they are not, that is your list of calls to make before the next afternoon at Keystone.

Permits, programs and the Village