Ground source heat pumps explained Installing a ground source heat pump
Ground source heat pumps aren't recommended for all homes. If your home isn't suitable you could end up with a system which doesn't deliver much for you and your money.
Our experts will tell you all the things you need to consider before taking the plunge with a ground source heat pump.
From the difference between a horizontal and vertical ground source heat pump system and how much space you'll need, to how to find an approved installer.
So make sure that you read on - it's worth taking time first to see how suitable your home is.
Ground source heat pump suitability
Here are some of the key considerations you need to think about if you are considering installing a ground source heat pump:
- The size of your home and garden. You'll need to have enough outdoor space to support the ground loop and pump, and access for digging machinery. Get an installer in to advise on your particular circumstances.
- Your existing fuel system. Savings will be greater if you replace an old or expensive heating system (like oil, LPG or electric heating) than if you are connected to the mains gas grid.
- What heating system you're using. A ground source heat pump produces low-temperature heat, so is best connected to a low heat system, such as underfloor heating – radiators are unlikely to achieve the same heat you might be accustomed to from boiler-powered central heating.
- Water heating. You may need a separate electric immersion heater.
- How well insulated your home is. Before considering a ground source heat pump, improve your home's energy efficiency with loft and cavity wall insulation. Otherwise you'll be paying to generate heat you're making little use of.
Horizontal and vertical ground source heat pump systems
The ground loop (the network of pipes pumping the water underground) can be fitted horizontally or vertically.
Horizontal systems are laid in a shallow trench over a wider surface area.
A vertical system buries the pipes in a borehole. Depending on the size of the system, the borehole could be anywhere between 15 and 100 metres deep.
The type of system you choose depends on the space you have available. Whatever the type, it is important that the system is correctly sized for your heating needs.
Get an approved installer
Households considering a ground source heat pump should use a Microgeneration Certification Scheme (MCS) installer and only get a properly accredited professional to complete the work.
The Energy Saving Trust (EST) conducted a trial to find out more about how people are using heat pumps and how efficient they are. During the course of the trial, the EST found a variety of heat pumps which were incorrectly installed. This meant the heat pumps didn't perform as efficiently overall.
It is essential to use an MCS-approved product and installer to qualify for the Renewable Heat Incentive which is a Government scheme paying householders who have renewable heat technologies. Find out more in our guide to the Renewable Heat Incentive.
New rules on how heat pumps can qualify for MCS from 26 September 2015 make it even more important than before to check that the heat pump you're thinking of getting is MCS approved. You can check this on the MCS website (product search).
We always recommend getting several quotes before choosing the best option for you.
The installation of a ground source heat pump typically takes one to two days for a professional installer to complete.
Heat pump energy labels
New regulation means that heat pumps will now have to have an energy label on them. The label gives information about the energy efficiency of the heat pump and rates products from dark green (most efficient) to red (least efficient).
From 26 September 2015, all new heat pumps that enter the market must be sold with an EU product label, and the installer should produce a package label that displays the efficiency based upon several different components in the heating system.
After 25 March 2016, all heat pumps certified by the Microgeneration Certification Scheme must be sold with a product label, and the installer must produce a package label. If your heat pump is not sold with a product label it may not be eligible for the RHI.
Ask the installer how you'll be able to control the ground source heat pump system, as understanding how to operate the system efficiently will help you get the most out of it.
Make sure the controls are user-friendly and the installer explains to you how to work the system. The EST's field trials found that many control systems were too complicated for homeowners to work effectively.
Your heating controls should allow you to pre-programme your system to switch on or off at different times.
For further tips on how to get the most out of a ground source heat pump, we've summarised more findings from the EST's heat pump user trial.