Air to Air Heat Pumps for Heating Your Home

Most people call them air conditioners. Technically, every system we fit is an air to air heat pump: an outdoor unit pulls heat out of the outside air, even on a frosty morning, and an indoor unit blows it into the room as warm air. Flip it into cooling in summer and it does the reverse. One installation, both seasons.

This page is the starting point for our heating guides. If you already know the room or the problem, jump straight to the page that fits:

What an air to air heat pump is — and what it isn't

There are two kinds of air source heat pump. An air to water heat pump replaces a boiler: it heats water for radiators or underfloor heating, and usually a hot water cylinder too. An air to air heat pump heats the air in the room directly through a wall-mounted indoor unit. No radiators, no cylinder, no changes to your plumbing.

That difference drives almost everything else:

• It heats fast. Warm air comes out within a couple of minutes of switching on. There's no body of water to heat up first.
• It's a smaller job. A single-room system is normally fitted in a day. There's no draining down, no radiator swaps and no new cylinder.
• It cools too. An air to water heat pump can't give you air conditioning. An air to air system does both.
• It doesn't heat your hot water. Your taps and shower still need a boiler, an immersion heater or a separate cylinder. We say this up front because it matters if you're planning to replace a boiler entirely.

What it costs to run in heating mode

A heat pump moves heat rather than making it, so it delivers several units of heat for every unit of electricity it uses. Based on Haier's seasonal efficiency (SCOP) ratings and the Ofgem price cap of 26.32p per kWh for October–December 2026, each kWh of heat costs roughly 7.3p. The same kWh from a plug-in electric heater costs 26.3p.

Those are full-output figures. Once a room is up to temperature an inverter unit throttles right back, so a typical hour costs less. See heating costs compared for how that stacks up against gas, oil, LPG and storage heaters.

Does it still work when it's freezing outside?

Yes. The systems we fit keep extracting usable heat from outside air well below zero. Efficiency drops as it gets colder, so a unit works harder on a -3°C morning than on a mild one, but it keeps heating. That's why we size for your coldest realistic day, not an average one. The how heat pumps work guide explains the physics in plain English.

One room, several rooms, or most of the house

A single split is one outdoor unit and one indoor unit, which is right for a home office, garden room, conservatory or bedroom. A multi-split runs two to five indoor units from one outdoor unit, each room with its own temperature. It's how we heat most of a bungalow or the main rooms of a house. The instant quote handles both. Enter each room and it picks the outdoor unit for you.

Haier systems, certified installers

We install Haier exclusively. Keeping to one brand means our engineers know the range inside out, we hold the right spares, and costs stay down. Haier systems come with a 6-year warranty as standard when installed by a certified engineer. Our engineers are F-Gas certified, the business is REFCOM registered, and electrical work is carried out to Part P standard. We're based in Buckingham, MK18, and cover Milton Keynes, Buckinghamshire, Northamptonshire and the surrounding area.

Heat pump installers near you

Milton Keynes Buckingham Bletchley Newport Pagnell Aylesbury Bicester Northampton Oxford

See the full list of areas we cover, or check recent installations for real examples of our work.

Common questions

Is an air to air heat pump the same as air conditioning?

Yes. Modern split air conditioning is an air to air heat pump: it can run in reverse, so the same system heats in winter and cools in summer. Every Haier system we install works in both modes.

How much does an air to air heat pump cost to run?

At the October to December 2026 Ofgem price cap of 26.32p per kWh, each kWh of heat costs roughly 7.3p based on Haier's seasonal efficiency ratings. A 3.5kW unit at full heating output costs about 25.6p an hour, and less once the room is up to temperature.

Can an air to air heat pump heat my hot water?

No. It heats the air in the room only. Hot water still needs a boiler, an immersion heater or a separate hot water system.

Do air to air heat pumps work in cold weather?

Yes. They keep extracting usable heat from outside air below zero. Efficiency falls as it gets colder, which is why we size each system for the coldest realistic conditions rather than an average day.

How long does installation take?

A single-room system is typically installed in one day. Multi-split systems serving several rooms usually take one to three days, confirmed at the free survey.

Is there VAT on an air to air heat pump?

Qualifying residential installations currently benefit from 0% VAT under HMRC's energy-saving materials relief, which runs until 31 March 2027. We confirm the VAT treatment on your written quote.