Beginners Guide: Ground Source Heat Pumps, an untapped domestic resource

Ground source heat pumps use pipes which are buried in the garden to extract natural heat from  underground by pumping water through it. The heat pump then increases in temperature, and heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home.


“How do these fandangled contraptions work?!”

Don’t worry technophobes its quite simple! A ground source heat pump needs electricity to run, but the idea is that it uses less electrical energy than the heat it produce. It circulates a mixture of water and antifreeze around a loop of pipe – called a ground loop – which is buried in your garden. The water and anti-freeze is pumped around the ground loop and absorbs the naturally occurring heat stored in the ground. The pump itself consists of 3 essential components; the evaporator, a compressor and a condenser – together these take the heat from the water mixture, transfers it to your domestic heating system i.e. your radiators and increases the temperature in the process. A ground source heat pump increases the temperature from the ground by between one and a half and four times – if the ground temperature is 12°C, the output would be between 18 and 48°C so you can say good-bye to those chilly winter mornings! And the best thing is 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 those harsh winters.

Will they ruin your garden?

No, not intentionally, unless the machines rise and have a thing against your flower garden! Joking aside; The length of the ground loop depends on the size of your home and the amount of heat you need. You’ll need sufficient space for installation of the system, generally with a garden that’s accessible for digging machineryLonger loops can draw more heat from the ground, but need more space to be buried in. If space is limited, a vertical borehole can be drilled instead.

Other Things to Consider when installing Ground Source Heat Pumps

  • 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
  • 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.
  • Water heating. You may need a separate electric immersion heater.

Lets get down to the important stuff, MONEY

Ground source heat pumps (GSHP) differ in size and complexity, so pinpointing a typical cost is tricky. The Energy Saving Trust (EST) estimates it can range between £11,000 and £15,000 to install one in your home. 
The payback period (the time it takes for the initial cost of the system to be recouped in energy savings) is also difficult to predict, as it depends on how efficiently your system works, the type of system you’re replacing, whether you can get financial support with the Renewable Heat Incentive and how you’ll be using the heat generated from the pump. Things to consider are:
  • A new build property will be generally more suited to a GSHP for retrofitting and RHI etc. 
  • How well insulated your home is.
  •  What you will be using the GSHP for as it is more suited for lower heat temperatures like radiators and underfloor heating
  • Running costs can be higher if you’re also using the system for your hot water supply, and you may require a supplementary electric immersion heater to keep up with your heating needs.
The EST estimates that an average performing ground source heat pump could save you:
  • between £650 and £1,035 a year to replace oil-fired heating
  • between £1,265 and £2,000 a year to replace electric heating 
Financial help is also available. The Renewable Heat Incentive (RHI) is a government scheme and the EST estimated it could provide an additional £2,325 to £3,690 a year which is big money.
What RHI can do for you

Pros of ground source heat pumps

  • Ground source heat pumps generate less CO2 than conventional heating systems which means they are eco friendly, no protesters outside your door!
  • The Energy Saving Trust (EST) says that a ‘typical’ ground source heat pump could save you between £395 and £2,000 a year depending which existing heating system you are replacing, either way it is a considerable amount of money worth taking back from those dastardly evil energy companies 
  • You can get financial help towards the cost of a ground source heat pump. The Renewable Heat Incentive scheme provides payments to householders who have a heat pump, estimated to be between £2,325 and £3,690 a year for an average four-bedroom detached home.
  • You need to use electricity to power the pump which circulates the liquid in the ground loop, but for every unit of electricity used by the pump, you get between two and four units of heat – making this an efficient way to heat a building.
  • Cheaper Economy 7 electricity tariffs can be used to lower the cost of electricity to power the heat pump, and special heat pump tariffs may be available from some electricity suppliers – alternatively consider solar photovoltaic panels or a wind turbine (if you live in a suitable area) for a greener source of electricity.

Cons of ground source heat pumps

  • Installing a ground source heat pump is expensive – typically £11,000-£15,000, depending on the size of the system (not including the cost of fitting under-floor heating, if required) BUT, don’t forget that you can make your money back, all that money is an investment
  • Ground source heat pumps are generally not suitable for properties with existing gas-fired central heating as the technology works at lower temperatures, making it better suited to homes with underfloor heating.
  • The groundworks required to dig the trench can be expensive and disruptive – planning permission may be required if space is at a premium and you need a borehole. Ground source heat pumps tend to be better suited to new-build homes as they can be planned as part of the construction process.
  • You still need to use electricity to drive the pump, so a ground source heat pump can’t be considered completely zero-carbon unless this is provided by a renewable source, such as solar power or a wind turbine.

Will you be doing your bit in saving the environment?

A Ground Source Heat Pump can help in lowering your CO2 emissions, reducing your carbon footprint by a considerable amount, helping you go down a few shoe sizes! According to the EST, a heat pump with mid-range efficiency uses a third of the energy needed in an average gas or oil boiler to produce the same amount of heat. Added up over a number of years this a significant amount so yes, you will be saving the environment you nice lovely people.

Its in our hands
Are you considering Ground Source Heat Pumps? Visit our website here to get a FREE reliable quote. Its quick and easy and based on our database we can give you the top 3 companies in your area that can do it for you

I bid you adieu my dear Sirs and Madams!