A heat pump is a device that transfers heat energy from a source of heat to what is known as a ‘heat sink.’ Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer by absorbing heat from a cold space and moving it to a warmer one, this is done using a very small amount of energy making heat pumps an excellent option for heating your home!
What do Air source heat pumps look like?
Heat pumps come in a range of shapes and sizes and generally consist of 4 different components – a condenser, an expansion valve, an evaporator and a compressor. The design of your heat pump depends on the size of your home, and whether you want to use your heat pump to heat your water. There is the option of what we call a ‘split’ unit or a ‘combi’ unit. A split unit has two components, the heat pump which is mounted on the outside of your home and the water tank which sits inside the house. The ‘combi’ unit includes both the heat pump and water tank in one body and sits inside of your home.
How do they differ from oil heating?
Unlike oil boilers, which heat water to 60 or 65 degrees, heat pumps heat the water to 30 or 35 degrees over a longer time frame/ more consistent basis. Heat pumps therefore work well with under floor heating and large radiators. If a house is being retrofitted larger radiators may need to be installed but often this is not necessary. Heat pumps can also be used to heat the hot water tank using a special low temperature coil.
Do they work in the Cold?
Yes, they do! Over 20% of all Swedish homes use Heat pumps as their main source of in-home heating. Heat pumps can work in any temperatures. However, the temperature can affect the efficiency of the heat pumps. Higher temperatures allow for a higher efficiency. The relationship between the amount of energy used to run a heat pump and the amount of energy it produces is called the COP. This stands for Coefficient of Performance. If a heat pump uses 2kW of electricity to produce 8kW of energy it has a COP of 4. Air source heat pumps in Ireland typically achieve a COP of 3 to 4. This means a home uses 1 unit or kWh of electricity for 4 units of heat produced.