Air-source heat pumps explained
The most common and affordable type of heat pump — here's how air-source systems work, what they cost, and how to choose one.
How air-source heat pumps work
An air-source heat pump moves heat between the outdoor air and your home using a refrigerant cycle. In winter it extracts heat from outside air — even cold air holds usable heat — and delivers it indoors; in summer it reverses to provide cooling. Because it moves heat rather than burning fuel, it delivers far more heating energy than the electricity it consumes.
Ducted vs ductless (mini-split)
Air-source systems come in two forms. Ducted units use your home's existing ductwork and a central air handler — simplest if you already have ducts. Ductless systems (mini-splits) use wall- or ceiling-mounted indoor heads connected to an outdoor unit, ideal for homes without ducts, additions, or room-by-room control.
Efficiency ratings: HSPF, SEER, COP
| Rating | Measures | Look for |
|---|---|---|
| HSPF2 | Seasonal heating efficiency | Higher is better (~7.5–10) |
| SEER2 | Seasonal cooling efficiency | Higher is better (15+) |
| COP | Instant heat moved per unit of electricity | 2.5–4 typical |
ENERGY STAR certified models meet minimum efficiency tiers and are usually required to qualify for state and utility rebates.
What air-source heat pumps cost
A ducted air-source system typically runs $5,000–$15,000 installed; ductless mini-splits run roughly $3,500–$5,000 per zone. State and utility rebates can reduce the net cost (the federal 25C/25D credit expired at the end of 2025). Estimate yours with our cost calculator.
Pros and cons
Pros: lower upfront cost than geothermal, heats and cools in one, qualifies for incentives, works in most climates. Cons: efficiency declines in extreme cold (choose a cold-climate model), and outdoor units need clearance and occasional defrost cycles.
Frequently asked questions
What is an air-source heat pump?
An electric system that transfers heat between outdoor air and your home for both heating and cooling, using a refrigerant cycle — the most common heat pump type.
Do air-source heat pumps work in winter?
Yes. Standard units work well into the 20s–30s°F; cold-climate models maintain efficient output below 0°F, with backup heat for the coldest days.
How long do air-source heat pumps last?
Typically 12–15 years with regular maintenance — similar to a central AC.
Are air-source heat pumps cheaper than geothermal?
Much cheaper upfront. Geothermal costs more to install but has lower running costs and a longer lifespan.
Related
Sources & further reading
Educational guide, reviewed against US DOE & ENERGY STAR guidance and updated June 2026. Estimates only — not a substitute for a professional assessment or Manual J load calculation.