What is an Air Source Heat Pump?
A heat pump that extracts heat from outdoor air and transfers it inside your home
An air source heat pump (ASHP) works like a fridge in reverse – it extracts heat from outdoor air even at temperatures as low as -20°C. ASHPs are cheaper to install than ground source (£7,000-£15,000) and qualify for the Boiler Upgrade Scheme's £7,500 grant in England and Wales (£9,000 for homes heated by oil or LPG with no mains gas, until 31 March 2027).
Where it wins
- Lower install cost than ground source (£7,000-£15,000)
- No garden excavation needed
- Qualifies for the Boiler Upgrade Scheme grant (£7,500 in England and Wales)
- Can provide heating and hot water year-round
Where it struggles
- Less efficient than ground source in very cold weather
- Outdoor unit produces some noise
- Requires adequate outdoor wall or ground space
- Best paired with underfloor heating or oversized radiators
How it works
01
Fan draws outside air over an evaporator coil containing refrigerant
02
Refrigerant absorbs heat and evaporates to gas
03
Compressor increases gas pressure and temperature
04
Hot gas passes through condenser releasing heat to home's water circuit
Air Source Heat Pump: common questions
What is an Air Source Heat Pump?
How does an Air Source Heat Pump work?
See what heat pumps cost in your town
Prices for 160 towns, with the grant position for your nation.