How heat pumps work, and what to check before installing one

A heat pump moves heat in either direction

An electric heat pump transfers heat between indoors and outdoors. In cooling mode, it removes heat from the home; in heating mode, it brings heat inside. An air-source heat pump uses outdoor air as its heat source or sink. Ground-source equipment uses the ground instead.

Ducted systems distribute conditioned air through ducts. Ductless mini-splits use indoor units serving rooms or areas. Some projects combine ducted and ductless equipment. The right layout depends on how heat and cooling can reach the rooms you actually use.

U.S. Department of Energy — Heat pump systems · Source checked 2026-09-06

Compare the layouts before comparing models

A room-by-room plan is more useful than starting with a brand. Tell the designer which spaces need conditioning, whether doors are normally open, and which rooms are currently uncomfortable.

Cold-weather performance needs a design check

Ask for the home’s heating load and the proposed heat pump’s heating capacity at the local winter design temperature. A cold-climate designation is useful when selecting equipment, but the installer still needs to match the system to the house. Ask when supplemental heat will operate and how it is controlled.

ENERGY STAR — Clean heating and cooling · Source checked 2026-09-06

What “backup heat” means in your proposal

Have the contractor identify whether the design includes electric resistance heat, a retained furnace, or another heat source. Ask these questions before comparing quotes:

• What indoor temperature and outdoor design condition does the proposal target?
• How much heating can the heat pump supply at that condition?
• When does supplemental heat turn on, and what energy source does it use?
• Which thermostat settings control normal operation and supplemental operation?
• What electrical work is included for the selected configuration?

Get the answers for the actual model combination. A generic assurance that a product “works in winter” does not establish how your home will perform.

Build a complete installation scope

Ask for one written project scope that covers equipment and the work needed to make it function in the house.

1. Home assessment and documented load calculation.
2. Outdoor equipment, indoor units or air handler, and controls.
3. Duct work or indoor-unit placement, refrigerant lines, and condensate drainage.
4. Electrical circuits and any panel changes identified by the assessment.
5. Removal or retention of existing equipment, permits, and inspections.
6. Startup checks, homeowner instruction, parts warranty, and labor warranty.

Mark each item included, excluded, or to be confirmed. If one quote retains a furnace and another removes it, the totals represent different projects.

Efficiency is not the same as your future bill

A heat pump’s operating cost depends on the heat the home needs, the equipment’s performance, controls, and energy prices. If you are replacing a fuel-burning heater, compare the heating cost for the same home and comfort target. Include the cost of any supplemental heat in the estimate.

For example, an invented $2,000 annual heating-cost estimate with $350 of supplemental electricity omitted is incomplete. Add that $350 before comparing it with another system. Ask whether cooling and maintenance are included too. Use the efficiency comparison calculator to explore the assumptions rather than treating one projected bill as guaranteed.

Two homes can need very different projects

Example 1: A homeowner already has central ducts and wants whole-home heating and cooling. The assessment must establish whether those ducts and the electrical setup can support the proposed heat pump. The quote should identify any changes instead of assuming reuse.

Example 2: A homeowner heats with radiators and only needs cooling in an addition. A proposal for one ductless indoor unit answers a different question from whole-home heating replacement. Ask which rooms are served and what equipment continues heating the rest of the house.

Neither example establishes a price or a recommendation. They show why matching the project scope comes before comparing the equipment price.

Check incentives before relying on them

Use the rebate guide directory to find potentially relevant programs, then confirm the current rules with the program administrator. Verify the address and utility territory, eligible equipment, installer requirements, application timing, and whether funding is available. Budget with no incentive until you have a supported amount; a possible reimbursement is not necessarily cash available to pay the installer.

Common question

Do I need ducts for a heat pump?

Ductless equipment provides an alternative to ducted distribution. The installer still needs a room-by-room delivery plan; one indoor unit should not simply be assumed to serve every closed bedroom or remote area. Compare the proposed coverage and controls with how you use your home.

Common question

Does installing a heat pump mean removing my furnace?

The proposal should say explicitly what stays and what goes. Ask for the reasons, the controls plan, and the price of each configuration under consideration. Retaining equipment affects maintenance and operating assumptions as well as the installation scope.

Prepare for a useful design conversation

Gather the current heating fuel and equipment models, recent energy bills, uncomfortable-room notes, and any planned renovations. Request a heat-pump installation assessment and ask for the scope checklist above. You choose whether to proceed after reviewing the provider’s design, price, and terms.