Ground Source Heat Pumps

Heat your home with energy from the ground.

A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe – called a ground loop – which is buried in your garden. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump. This heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home. The ground stays at a fairly constant temperature under the surface, so the heat pump can be used throughout the year – even in the middle of winter.

The length of the ground loop depends on the size of your home and the amount of heat you need. Longer loops can draw more heat from the ground, but need more space to be buried in. Normally the loop is laid flat or coiled in trenches about two metres deep, but if there is not enough space in your garden you can install a vertical loop down into the ground to a depth of up to 100 metres for a typical domestic home.

Ground Source Heat Pump Example
Ground Source Heat Pump Example

The benefits of ground source heat pumps 

  • Lower your fuel bills, especially if you replace conventional electric heating
  • Provide you with income through the government’s Renewable Heat Incentive (RHI)
  • Lowers your home’s carbon emissions
  • Can heat your home and provide hot water
  • Needs little maintenance – they’re known as the ‘fit and forget’ technology

Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. 

Savings

How much you can save will depend on what system you use now, as well as what you are replacing it with. Your savings will be affected by:

  • Your heat distribution system - If you have the opportunity, underfloor heating can be more efficient than radiators because the water doesn’t need to be so hot. If underfloor heating isn’t possible, use the largest radiators you can. We will advise you.
  • Water heating -  If the heat pump is providing hot water then this could limit the overall efficiency.  You might want to consider solar water heating to provide hot water in the summer and help keep your ground source heat pump efficiency up.

Using the controls effectively will mean get the most out of your system. You may need to set the heating to come on for longer hours, but you may be able to set the thermostat lower and still feel comfortable.

Potential annual savings, in an average three-bedroom semi-detached home with a typical ground source heat pump installation:

Existing System Savings per year Ground source heat pump performing at 250% Ground source heat pump performing at 300%
Gas £
Carbon Dioxide
-£20
400kg
£110
850kg
Electric £
Carbon Dioxide
£510
4,780kg
£650
5,230kg
Oil £
Carbon Dioxide
£160
1,200kg
£290
1,660kg
Solid £
Carbon Dioxide
£160
4,980kg
£290
5,430kg

A zero saving means it could cost you just as much to run the heat pump as the system you are replacing. We’ve assumed average boiler efficiency for each fuel type; ground source heat pumps produce more energy (as heat) than they use (as electricity), so their efficiency is more than 100%.

Earnings

You may be able to receive payments for the heat you generate using a heat pump through the government’s Renewable Heat Incentive (RHI). 
You may also be able to get help with the installation costs of a ground source heat pump through the Renewable Heat Premium Payment scheme.

Maintenance

Ground Source heat pump systems typically come with a ten year warranty. With regular maintenance, you can expect them to operate for 20 years or more. A yearly check by you and a more detailed check by us every three to five years should be sufficient. 

Planning permission

In England, Scotland and Wales, domestic ground source heat pumps are generally allowed as permitted developments. We will advise you and provide assistance.

Is a ground source heat pump suitable for me?

  • Is your garden suitable for a ground loop?
    It doesn’t have to be particularly big, but the ground needs to be suitable for digging a trench or a borehole and accessible to digging machinery.
  • Is your home well insulated?
    Since ground source heat pumps work best when producing heat at a lower temperature than traditional boilers, it’s essential that your home is well insulated and draught-proofed for the heating system to be effective.
  • What type of heating system will you use?
    Ground source heat pumps can perform better with underfloor heating systems or warm air heating than with radiator-based systems because of the lower water temperatures required.
  • Is the system intended for a new development?
    Combining the installation with other building work can reduce the cost of installing the system.