Heat pumps provide heat from renewable sources and are increasingly being used by homeowners as a viable alternative to oil-fired boilers to provide heating and hot water.

How heat pumps work

Heat pumps take low-level heat from the surroundings and compress it to raise its temperature so it can be used to heat your home and provide hot water.  The heat source in question can be the air, the ground or even a nearby source of water.

Air-source heat pumps work like air-conditioners in reverse, extracting warmth from the outside air and typically transferring it at a higher temperature into the central heating and hot water system.  Working in a similar fashion, ground-source heat pumps take warmth from the ground via pipework buried in trenches or boreholes and water-source heat pumps source all the heat they need from a nearby river or lake.

Although heat pumps use electricity, they have the potential to generate at least three units of heat for each unit of electricity they use – this means they should be at least as efficient as a gas boiler in carbon and energy cost terms, although this is also very dependent on factors such as design, commissioning and patterns of use.  Heat pumps work most efficiently if they run at a lower temperature for a longer period of time and are therefore best suited to use with underfloor heating systems.

The Renewable Heat Incentive

Heat pumps benefit from a Government scheme called the Renewable Heat Incentive (RHI). The scheme aims to cover the additional cost of the heat pump over and above a replacement oil boiler by providing you with a payment for each unit (kWh) of heat generated by the system. The RHI is payable for seven years but is only payable if your home has loft and cavity wall insulation installed (where applicable). To the end of December 2016 the payments are:

  • ground-source heat pump system - 19.33p for each unit (kWh) of heat generated
  • air-source heat pump system - 7.51p/kWh

Home Energy – Heat Pumps (L1)                                                                                               WinACC November 2016

 

Attachments

AttachmentSize
WinACC - Heat pumps - L1.pdf120.65 KB