Air source heat pumps are very efficient. While they run on electricity, some boast an efficiency rating as high as 300%. This means that for every unit of electricity the pump uses, it produces 3 units of useful heat. Consider that many “efficient” gas boilers operate at 90% efficiency, and it is easy to see why air source pumps for heating and cooling have become so popular.
So how does the air source heat pump work?
The heat pump is located outside the house. It uses a fan to draw air into it and this is passed over a heat exchanger. The refrigerant liquid contained within the exchanger is heated by the latent heat in the air until it eventually turns to a gas. Compressing the gas greatly increases the heat before it is passed back through another exchanger so that it is turned back into a liquid. The hot liquid can then be used for heating or for other purposes.
Heat pump types
There are two basic types of air source heat pump – air to air, and air to liquid heat pumps.
- Air to air are the simplest heat pumps. They draw air from outside the property and are used to create hot air. This is then fed through the property using fans. The method is simple but effective.
- An air to liquid heat pump is the more popular choice. It converts latent heat from outside into hot water. This hot water is fed through heating pipes or offered through mains taps. It can be used to heat a property or can even be used to power an air conditioning unit. Powering an air conditioning unit using latent heat is highly effective because air conditioning is required when the temperature outside is at its highest.
All heat pumps of this type require some electricity to run. They include pumps and other electrical components that simply will not run unless they are powered by mains electricity.
These heat pumps work more efficiently during the summer months because there is more latent heat in the air, but they can still draw heat even during the winter months, providing your property with an efficient means of enjoying hot water or central heating.