Yes. Most modern split air conditioning systems have a heat mode, and in heat mode they work as an air-to-air heat pump, pulling warmth from the outside air and blowing it into the room. They’re very good at heating individual rooms such as a home office, conservatory or bedroom, though for most homes they work alongside the boiler rather than replacing it. If you already have air conditioning fitted, or you’re thinking about air con in Bishop’s Stortford or Dunmow, it’s worth knowing how to use it through the winter.
How air conditioning heats a room
In summer, an air conditioner takes heat out of the room and releases it outside. In heat mode it simply runs that process in reverse. The outdoor unit collects heat from the outside air, even when it feels cold, and the indoor unit releases it into the room.
Because it moves heat rather than making it, a good system can deliver more heat energy than the electricity it uses. That’s why air-to-air systems are classed as a type of heat pump.
Where heating with air con works best
Air conditioning heats the air in one room quickly, so it suits spaces that need warmth on demand:
- Home offices and garden rooms, where you want heat during the working day without running the whole house
- Conservatories and extensions, which often struggle to stay warm on radiators alone
- Bedrooms and loft rooms, especially those that are cold in winter and hot in summer
- Rooms used at odd times, such as a hobby room or guest room
It’s less suited to heating a whole house on its own unless several indoor units have been designed for that job. It also doesn’t heat your hot water, so a boiler or cylinder is still needed for that.
What to expect on cold days
Air con in heat mode behaves a little differently from radiators.
The defrost cycle
When it’s near freezing and damp, frost can build up on the outdoor unit. The system will pause heating every so often to defrost itself. You may see steam from the outdoor unit and notice the indoor fan stop for a few minutes. That’s normal.
Warm air, not hot radiators
The air coming out feels warm rather than hot, and the room heats evenly rather than having one hot spot by the window. Setting a steady temperature works better than turning it right up and down.
Running costs
How much it costs depends on your electricity tariff, the size of the room and how well it holds heat. Our post on how much home air conditioning costs to run explains the main factors.
Getting the most from air con heat mode
A few simple habits help:
- Keep the indoor unit’s filters clean, as dusty filters reduce airflow
- Make sure the outdoor unit is clear of leaves, snow and anything stacked against it
- Set the louvres to point downwards in heat mode, as warm air rises
- Keep doors closed so the unit is heating one room, not the hallway
- Use the timer to warm the room before you need it
If the unit starts making new noises, leaks water indoors or stops heating properly, call an F-Gas qualified technician. Don’t open the casing or touch the refrigerant pipework.
Air con heating in Saffron Walden, Dunmow and Bishop’s Stortford
Homes across north Essex and east Hertfordshire range from period cottages to newer estates with loft conversions and large extensions. Many have one or two rooms the main heating never quite reaches, which is where a wall-mounted unit can make the biggest difference.
In older properties around Saffron Walden, adding radiators to a new space isn’t always practical. An air con unit avoids extending the pipework and gives you cooling in summer too. If you’re still weighing it up, our guide to whether air conditioning is worth it covers the pros and cons.
Frequently asked questions
Does air conditioning work as heating when it’s freezing outside?
Yes, most modern systems keep heating well below freezing, though output can drop as temperatures fall and the unit will pause to defrost. Check the manufacturer’s operating range for your model. In a typical British winter, a well-sized system should keep a room comfortable for most of the season.
Is heating with air con cheaper than using a boiler?
It depends on your energy prices and how efficient your boiler is. Air-to-air systems can be efficient because they move heat rather than burn fuel, but electricity costs more per unit than gas. For heating a single room on demand, it can work out well compared with running the whole central heating system.
Should air con be serviced before winter?
It’s a good idea. A service checks the filters, coils, drainage and refrigerant performance so the unit heats efficiently through the colder months. Many manufacturers also recommend regular servicing to keep warranties valid. Book it before the cold sets in so the unit is ready when you need it.
Thinking about air con for winter heating?
If you’d like to heat a cold room with air conditioning, or get an existing unit checked, give us a call on 01279 771981 or drop us a message and we’ll talk through the best option for the space.