Many modern split air conditioning systems can heat as well as cool. In heating mode, the system works as an air-to-air heat pump, moving heat into the room rather than generating heat like a simple electric heater.
Where heating mode helps
Heating mode can be useful in bedrooms, garden rooms, loft conversions and home offices where you want fast room-by-room comfort. It can also help in shoulder seasons when you do not want to heat the whole house.
If that room sits in a detached studio or garden office, City Air’s guide to garden room air conditioning in London explains what changes when the conditioned space is separate from the main house.
It can also make a big difference in glazed spaces that swing between too hot and too cold through the year. If that is your main problem room, see City Air’s guide to air conditioning for conservatories in London.
What it does not do
An air-to-air system heats the air in the room. It does not provide hot water. It is different from an air-to-water heat pump that connects to radiators, underfloor heating and a hot water cylinder.
Why sizing still matters
The system should be sized for the room and the way you use it. A loft office may need different thinking from a small bedroom. Good placement also helps heating feel comfortable rather than draughty.
Official background
The Energy Saving Trust explains that air source heat pumps move heat from outside air into the home. For homeowners comparing low-carbon heating options, it is worth reading their guidance and then speaking to an installer about the specific room you want to condition.
