What Is a Heat Pump?
As the name suggests, a heat pump transfers or pumps heat from one place to another. Notice the use of the word “pump”- heat is not generated but rather is moved. Heat pumps can work with radiators or underfloor heating systems.
The heat pump performs the same role as a boiler in a central heating system, but it uses ambient heat from the ground or air, rather than burning fuel to generate heat.
What's So Good About Heat Pumps?
They’re incredibly efficient, especially Ground Source Heat Pumps which are 400 to 500% efficient.
Simply put, a heat pump is a device that uses a small amount of energy to move heat from one location to another. You’ve probably got a heat pump at home already – your fridge.
A fridge takes the heat out of the items inside and pumps this heat out to cool the items down. The back of your fridge is warm when it is operating because it is pumping extracted heat to the outside.
The Benefits of Heat Pumps
- much lower fuel bills – roughly half the cost of heating with oil boilers
- low carbon emissions
- no potential for carbon monoxide poisoning
- no fuel deliveries needed
- can heat your home as well as your water
- minimal maintenance required
Air Source Heat Pumps
An Air Source Heat Pump (ASHP) uses a fan to draw air over a heat exchanger which looks very similar to a car radiator. The heat exchanger then transfers its heat to a compressor where the heat energy is greatly amplified and then transferred to the radiators or underfloor heating.
Ground Source Heat Pumps
A Ground Source Heat Pump (GSHP) system works in a similar way to an ASHP but harnesses natural heat from underground by pumping water in pipes set in the ground (ground loop). The water in the pipes is heated as it circulates, the heat pump then increases the temperature, and the heat is used to provide home heating and hot water.
A GSHP can be utilised with geothermal boreholes (typically 75-100m underground) to harness the latent heat underground. Boreholes can be expensive whilst Horizontal Trenches usually require a significant amount of land.
Ground Source Heat Pumps have a higher efficiency than their Air Source counterparts as the temperature of the ground is fairly stable at around 7 degrees or so year-round.
Air source products must work with the ambient temperature which could be anything including minus temperatures which is when the heat pump has to work hardest and therefore the efficiency is not as great as a Ground Source system.