An air-to-air heat pump takes heat from the outside air and delivers it straight into rooms as warm air through indoor units, usually mounted high on a wall. The same system can run in reverse to cool rooms in summer. Unlike an air-to-water heat pump, it does not use radiators or underfloor heating and does not heat a hot water cylinder.
Top-floor rooms in Hertfordshire that overheat in summer gain from the cooling an air-to-air system provides. Flats in Hertfordshire on storage or panel heaters can often switch to air-to-air without fitting radiators or pipework. A survey in Hertfordshire covers indoor unit positions, pipe routes and hot water for homes across Hertfordshire.
Who it suits
- Extensions, conservatories and garden rooms
- Flats and apartments with storage or panel heaters
- Households that already have, or will add, a separate source of hot water
- Rooms that get too hot in summer as well as cold in winter
Grants and rules for heat pumps in England
Homes in Hertfordshire can use the Boiler Upgrade Scheme, which takes £7,500 off the cost of an air source heat pump when it replaces fossil-fuel or electric heating. Replacing oil or LPG heating qualifies for £9,000 for installations from 21 July 2026 to 31 March 2027, and air-to-air systems for £2,500. The MCS-certified installer named in your quote applies for the grant and deducts it from the price.
There is no VAT on installing a heat pump anywhere in the UK until 31 March 2027. In England most houses can have an air source heat pump under permitted development, provided the unit meets the MCS noise and siting standards; the old 1 m boundary limit was removed on 29 May 2025. We flag listed buildings, flats and sensitive conservation-area positions at survey.
Air-to-air heat pumps prices in Hertfordshire
The ranges below are typical installed prices for homes in Hertfordshire, including VAT. A survey sets the exact figure, because two similar-looking houses in Hertfordshire can need quite different radiators and pipework.
| System | Installed guide price |
|---|---|
| Air-to-air heat pump, 1–2 rooms | £2,500–£5,250 |
| Air-to-air heat pump, multi-room 3–4 bedroom home | £4,200–£8,400 |
Installed, inc VAT. Air-to-air systems heat (and can cool) rooms but do not provide hot water. In England and Wales the Boiler Upgrade Scheme gives £2,500 towards an air-to-air system in a home, deducted from your quote where eligible.
Towns we cover in Hertfordshire
We cover 17 towns in Hertfordshire for air-to-air heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Hemel Hempstead | HP2 | Berkhamsted | 7 h 47 min |
| Stevenage | SG1 | Hitchin | 7 h 45 min |
| St Albans | AL1 | Radlett | 7 h 47 min |
| Welwyn Garden City | AL8 | Hatfield | 7 h 46 min |
| Cheshunt | EN8 | Hoddesdon | 7 h 47 min |
| Hatfield | AL10 | Welwyn Garden City | 7 h 47 min |
| Bishop's Stortford | CM23 | Ware | 7 h 46 min |
| Hitchin | SG6 | Letchworth Garden City | 7 h 45 min |
| Hoddesdon | EN11 | Ware | 7 h 47 min |
| Letchworth Garden City | SG6 | Hitchin | 7 h 45 min |
| Harpenden | AL5 | St Albans | 7 h 46 min |
| Hertford | SG13 | Ware | 7 h 47 min |
| Berkhamsted | HP4 | Tring | 7 h 47 min |
| Ware | SG12 | Hertford | 7 h 46 min |
| Royston | SG7 | Letchworth Garden City | 7 h 44 min |
| Radlett | WD7 | St Albans | 7 h 48 min |
| Tring | HP23 | Berkhamsted | 7 h 47 min |
Air-to-air heat pumps questions
Is there a grant for air-to-air heat pumps?
In England and Wales, yes: the Boiler Upgrade Scheme includes a grant of £2,500 for air-to-air heat pumps in homes, from 28 April 2026. The MCS-certified installer applies to Ofgem and deducts it from your quote, subject to the scheme's conditions. The scheme does not cover Scotland or Northern Ireland; in Scotland, Home Energy Scotland has its own rules.
Can air-to-air heat pumps cool as well as heat?
Yes. Most air-to-air systems can reverse their cycle to cool and dehumidify rooms in summer, which makes them useful for loft rooms, south-facing extensions and home offices that overheat. Cooling uses electricity, so running costs rise if it is used heavily. You control heating and cooling for each room separately.
How do I look after an air-to-air system?
Clean the indoor unit filters regularly, typically every few weeks during heavy use and following the manufacturer's guidance, and keep the outdoor unit clear of leaves and snow. Annual servicing is recommended and is often a condition of the manufacturer's warranty. Any work on the refrigerant circuit must be done by an F-gas certified engineer.
Can an air-to-air heat pump heat my water?
No. An air-to-air heat pump heats and cools the air in rooms but does not produce hot water. You need a separate source, such as an existing immersion cylinder, a hot water heat pump or an electric water heater. If you want one system for heating and hot water, an air-to-water heat pump with a cylinder is the alternative.

