Ground Source Heat Pumps: A Friendly Introduction

With many recent advances in renewable technologies, many home-owners are looking at the possibility of investing in renewables.

Whilst the popularity of many renewable technologies has grown, ‘Ground Source Heat Pumps’ or ‘GSHPs’ have remained relatively under the radar.

In April 2014 it was announced that domestic Ground Source Heat pumps installations would now qualify for the RHI (renewable heat incentive). This means that home-owners who install ground source heat pumps receive a quarterly payment as well as significantly reducing their energy bills. The popularity of ground source heat pumps has significantly increased since the launch of the RHI, however, many are still unsure about investing in ground source heat pumps. This is most likely because they sound far more complex and messy than they actually are.

Here at Switch 2 Renewable we love ground source heat pumps, so in this blog post we wanted to shed some light on what ground source heat pumps actually are, and what home-owners can gain by investing in a GSHP. However, we will also look at some considerations which must be taken into account before investing.

What are Ground Source Heat Pumps (GSHPs)?

Put simply, GSHPs use electricity to extract heat from the ground, convert it to a higher temperature and then transfer it into a building.

A GSHP has three main components; collector, heat pump and distributor.

The collector refers to the pipes which are buried under the ground in order to extract the heat energy from the ground they are commonly referred to as ‘slinkies’. The pipes contain a heat exchange liquid, and they are buried horizontally (at least 1.2m underground) or vertically (around 15-150m deep). The liquid in the pipes extracts the heat from the surrounding soil – this liquid then moves through the pipes into the heat pump.

How the pipes of are buried (e.g. vertically or horizontally) depends on how much space is available at the property in question. This is something which an installation team will establish for you.

The liquid then moves through three parts of the heat pump. The first part is the evaporator; here the heat from the liquid meets the refrigerant. This forms a vapour which is then fed into the compressor. The compressor causes the vapour temperature to rapidly increase; this vapour is then forced into the final part of the heat pump, the condenser. The condenser then passes this heat on to the heating system.

The heating system or the ‘distributor’ is the final component of the GSHP, where the heat enters the building, either through under-floor heating or radiators.

Technology which works for you

Once a GSHP is installed it makes no noise, requires little/no maintenance and will last, untouched for several years.

Not only is a GSHP low maintenance, but it is also energy efficient. For every unit of energy used to drive the pump around 4 units of heat are produced. Traditional boilers on the other hand produce only one unit of heat per unit of electricity. This means you also save money on running costs.

So you save money on running costs, on heating bills and you are able to earn money through the RHI. With the domestic RHI now in place, home-owners need not be put off by the up-front cost of a GSHP system as they are guaranteed a long-term return and a fast payback. The RHI is available for both domestic and non-domestic installations.

What is the RHI?

The Renewable Heat Incentive is a tariff paid to the installation owner for the heat generated by the heat pump (similar to the FiT paid discussed in previous post). There will be another post looking at the RHI in depth, however, for now here are some simple facts:


While there are so many benefits to installing a GSHP some properties are not suitable, and not all installations are done to the same standard.

When fitting to a GSHP to an existing building (i.e. not a new-build) certain things must be taken into consideration. Installers must check your property to check it is compatible with a heat pump before it can be installed. GSHP installations are far more compatible with homes which are well insulated. Switch 2 Renewable and various other companies can check the insulation of your home before you decide to go ahead with installing a GSHP. This will ensure you are making a viable investment by choosing to install a GSHP.

Additionally, a large amount of garden space is required in order to bury the slinkies (as mentioned earlier) horizontally in the ground. Fortunately, there is still the option of digging a borehole and placing the pipes vertically; however, this option is a little more expensive.

Also, if you are renting a property, only the owner of the property is eligible to receive the RHI payments.


So, we have taken a look at what a ground source heat pump actually is, the benefits of installing one and any considerations you have to take into account before installing one. This is a relatively basic overview; however, it gives you the essentials you need to know before you consider installing a GSHP.

In brief, here’s what a ground source heat pump can do:

  • Provide 100% of your water and heating requirements
  • Operate all year round
  • Generate income through the RHI scheme
  • Significantly reduce running costs as opposed to a traditional boiler
  • Last for over 25 years

GSHP also have the added benefits of:

  • No required planning permission
  • Easy installation
  • Safe and easy to use
  • Quiet operation

They almost sound too good to be true! But, we can assure you they’re not!!

If you are thinking about installing a GSHP or simply want more information, please get in touch with our team and we’ll be happy to help!

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