Ground Source Heat Pumps
Ground source heat pumps transfer the heat from the ground into a building using a buried ground loop which provides heating and can also pre-heat hot water.
We can supply our ground source heat pumps to clients in Devon, Somerset and Dorset.
The Benefits of Ground Source Heat Pumps
The efficiency of a ground source heat pump is measured in the same way as an air source heat pump. The average CoP ( coefficient of performance) is about 3-4 units which is known as seasonal efficiency but some systems might produce a better rate.
For every unit of electricity that is used to pump the heat, about 3-4 units of heat will be produced which makes it a very efficient method of heating a building. If electricity from the grid will be used then a range of energy suppliers will need to be consulted to be able to benefit from low running costs.
How Ground Source Heat Pumps Work
There are three main parts to a ground source heat pump:
The ground loop This consists of lengths of pipe in the ground, which can either be in a horizontal trench or a borehole. The pipe is filled with antifreeze and water and is usually closed circuit. This mixture is circulated around the pipe to absorb heat from the ground. The ground loop can either be:
- Vertical, for use in boreholes
- Horizontal, for use in trenches
- Coil, 'slinky' or Spiral, also for use in trenches
Heat Pump The pump operates in a similar way to a fridge which uses refrigerant to take heat from indoors to keep food cool but the ground source heat pump takes heat from the ground to be able to heat a building. Ground source heat pumps consist of three main parts:
Heat distribution System
- The evaporator: This is used to absorb heat using a liquid in the ground loop.
- The compressor: This is what circulates the refrigerant around the heat pump and also compresses the refrigerant to the correct temperature that is needed for the heat distribution circuit.
- The condenser: This gives up the heat to the hot water tank to be able to supply the heat distribution system.
This consists of radiators or under floor heating for space heating and water storage for the supply of hot water.
Is It Suitable For My Home?
If you're thinking of installing a ground source heat pump then you should consider the following issues.
- Space is required outside to be able to install the ground loop.
- Suitable ground will be needed for digging a trench or borehole.
- The fuel that is being replaced. If it's LPG, coal, oil or electricity then the savings will be much better than gas. If gas is unavailable then heat pumps are a good solution.
- The type of system to distribute heat. Under floor heating is recommended as it works better at lower temperatures. Radiators can be used with ground source heat pumps but they will be larger compared to conventional boiler systems.
- Want to cut your home's carbon dioxide emissions further? Installing another form of renewable energy system to generate electricity or install solar PV to power the pump and compressor.
- Is the system for a new building development? Costs can be reduced if the installation is combined with other building works.
- Have you got sufficient insulation installed? Proper insulation in the floors, loft and walls will help lower the demand for heat which will make the system more efficient.
Costs and savings
A standard of 8-12kW system will cost around £6,000-£12,000 (price of distribution system not included). The cost will wary depending on the property and location. A ground source heat pump can save as much as 7 tonnes of CO2 a year and £880 on heating bills if installed in an electrically heated house. The savings will also vary depending on the fuel that will be replaced.
As well as ground source heat pumps, we also offer high quality air source heat pumps, solar thermal systems and biomass.