Most people think of air conditioning as a summer thing: something you switch on when a room gets stuffy and forget about the rest of the year. Fair enough. But here’s what a lot of homeowners don’t realise. Most modern air conditioning units can heat a room too, and they’re often already doing it in homes up and down the country.
Can your air conditioning unit heat your home?
Short answer: yes, in most cases. If your system was installed in the last several years, it’s almost certainly a reversible unit, which means it can run in heating mode as well as cooling mode.
The misconception is understandable. AC gets marketed and talked about as a cooling product, so the heating side of it tends to get missed. But the technology to heat with air conditioning has been standard in most residential split systems for years now.
How air conditioning heats a room
The mechanism is simpler than it sounds. Your air conditioning unit doesn’t generate heat the way a boiler or an electric heater does. Instead, it works like a heat pump: it pulls heat out of the air outside and moves it indoors.
In cooling mode, the system takes heat from inside your home and releases it outside. In heating mode, the cycle simply runs in reverse. The same refrigerant, the same components, just working the other way round. That’s why a heat-and-cool unit doesn’t need any extra kit to warm a room; it’s built into the system from the start.
What it’s like using AC as heating
This isn’t a slow burn either. We’ve fitted enough of these systems to know that a room warms up fast, usually within about ten minutes of switching to heating mode.
Where it earns its keep is in spaces that don’t get proper coverage from a home’s central heating: home offices, garden rooms, extensions, or a loft conversion that always runs a bit cold. One unit, doing both jobs, all year round.
The upsides of heating with air conditioning
No second heating system needed.
If a room doesn’t have radiators, or you’re not keen on running a whole extra pipe run out to an extension, a heat-and-cool AC unit solves that without extra plumbing.
Cheaper than heating you don’t need.
Warming one room with AC can cost less than running your central heating to heat the whole house for the sake of one space. The operational efficiency of heating with AC can also mean less power use than electrical heaters or gas.
Be aware of the differences
It only heats the room it’s in.
A wall-mounted or ceiling unit can’t feed radiators or underfloor heating elsewhere in the house. It’s a room-by-room solution, not a whole-home one.
Running in winter.
If a unit is turned off and the temperature outside is below freezing, the heating unit will still operate at the same efficiency. However, it will take time to kick in, going through a de-frost sequence before heating the room.
Instead, set the thermostat to a reasonable temperature and leave it on. If the room dips below that temperature, heating will start straight away, and the machine won’t have to defrost.
Grant eligibility depends on the setup.
A standard air conditioning unit doesn’t qualify for the Boiler Upgrade Scheme. Only systems specifically certified and installed as an air-to-air heat pump do, so check before assuming a grant applies.
Understand what’s realistic for your space
A few quick questions worth asking yourself:
- Are you trying to heat one room, or the whole house?
- Does the space already have a working heating source, or is this filling a gap?
- What’s your budget looking like, and would running one unit for both jobs actually save you money over the year?
If you’re just looking to heat one room that your central heating misses, such as a conservatory, shed or loft conversion, a heating-and-cooling AC unit is worth a proper look. For multiple rooms, you’ll need a more complex system, but it is still achievable.
Get in touch and we’ll help you work out whether heating-and-cooling AC makes sense for you.