Air-to-air heat pumps: air conditioning that heats your home

How air conditioning heats

An air conditioner moves heat rather than making it. In summer it takes heat out of your room and dumps it outside. In heating mode it runs in reverse: the outdoor unit pulls heat out of the outside air, even on a cold day, and the indoor unit blows it into the room as warm air.

Because it's moving heat instead of burning fuel or running a heating element, a good unit delivers four to five units of heat for every unit of electricity over a season. HMRC's own VAT guidance says most air conditioning units are air source heat pumps.

It heats air, not water. An air-to-air system won't give you hot water for taps or showers, and it doesn't connect to radiators. You keep your boiler or cylinder for hot water.

What it costs to run per hour

Worked out at the Ofgem price cap for 1 October to 31 December 2026: 26.32p per kWh of electricity, the GB average for Direct Debit. Efficiency figures come from manufacturer spec sheets for a premium Daikin Perfera and a value-range Panasonic TZ.

Heating costs more per hour than cooling because the same unit puts out more heat in heating mode. Inverter units slow down once the room reaches temperature, so most hours cost less than the flat-out figure.

Cost per kWh of heat compared

The fairest comparison is what each kWh of heat in the room costs you. Prices are from the same Ofgem cap period, without standing charges.

At these prices, air-to-air heating costs less per kWh of heat than a gas boiler whenever the seasonal efficiency is above about 3.

SCOP explained

SCOP is the seasonal coefficient of performance. It's the heat a unit delivers across a typical heating season, divided by the electricity it uses. A SCOP of 5.2 means 5.2 kWh of heat for every 1 kWh of electricity, averaged over the winter.

COP is the same idea measured at a single test condition. SCOP is more useful because it includes mild days, cold days and the unit slowing down. For cooling, the seasonal figure is called SEER. Both are on the product's energy label, using an average European climate.

Higher is better. Value ranges such as the Panasonic TZ reach a SCOP of 4.6, and premium ranges such as the Daikin Perfera reach 5.2. Over a winter of regular use, that gap shows up on your bill.

The £2,500 Boiler Upgrade Scheme grant

Since 28 April 2026, the Boiler Upgrade Scheme in England and Wales has included a £2,500 grant towards an air-to-air heat pump. It exists in law. In practice nobody can claim it yet, because the grant needs an MCS-certified installer and no installer can get MCS certification for air-to-air yet. As of September 2026, the certification bodies were still waiting for their own accreditation. By July 2026, 62 people had applied and no vouchers had been issued.

We're not MCS certified, because nobody can be for air-to-air yet. We'll never add a grant to a quote until it can really be claimed. If you'd rather wait for it, tell us and we'll let you know when installers can apply.

• Homes only, in England and Wales. Business premises don't qualify
• It must replace your existing fossil fuel or electric heating. You can't keep the gas boiler for heating
• It can't replace an existing low-carbon heating system
• The system must meet the whole home's heating demand, so one bedroom unit won't qualify
• The installer applies and takes the grant off your bill as an upfront discount

Air-to-air or air-to-water?

Both are heat pumps that take heat from outside air. What they deliver it into is the difference.

Where air-to-air heating works best

Air-to-air heating makes most sense where you want cooling in summer too, or where the current heating is expensive. It warms a room quickly, and each room is controlled on its own.

• Loft conversions and extensions that the existing radiators struggle to heat
• Flats with electric panel heaters or storage heaters, where running costs can fall sharply
• Home offices and garden rooms used during the day
• Bedrooms that overheat in summer and feel cold in winter
• Whole homes, with a properly designed multi-split and a heat loss calculation for each room

Prices for heating-capable systems

Every system on this list heats and cools.

• A bedroom or study

  2.5 kW wall unit, 5 m pipe, fitted in a day

  from£1,850inc. VAT

• A living room

  3.5 kW wall unit

  from£2,050inc. VAT

• Open plan or a loft

  5 kW wall unit

  from£2,450inc. VAT

• Two rooms, one outdoor unit

  Multi-split

  from£3,650inc. VAT

• Three rooms

  Multi-split

  from£5,100inc. VAT

• Four rooms

  Multi-split

  from£6,500inc. VAT

Heating with air conditioning: questions