Ground Source Heat Pumps  use pipes buried in the garden, or land adjacent to the premises, to extract heat from the ground. This heat can then be used to power radiators, underfloor or warm air heating systems and hot water. The system circulates a mixture of water and antifreeze around a loop of pipe, called a ground loop, that is buried in the ground. Heat from the ground is then absorbed into the fluid and passes through a heat exchanger into the heat pump. Under the surface the ground stays at a virtually consistent temperature all year around and therefore GSHP systems produce a very reliable source of heat.

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 fuel will you be replacing? The system will pay for itself much more quickly if it’s replacing an electricity or coal heating system. Heat pumps may not be the best option for homes using mains gas.
  • 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

Benefits of Ground Source Heat Pumps

Frequently Asked Questions

A Ground Source Heat Pump can produce 3 to 4 kilowatts (kW) of heat for every 1 kW of electricity it consumes. Using freely available heat energy from the ground, it generally achieves higher efficiency than any other heating system.  By creating 3 to 4 times the amount of energy it consumes.  A heat pump can reduce a property’s heating costs by around two-thirds compared to direct electric heating.

A system of pipes is buried in trenches typically 1.2m deep and 1.2m wide. The pipe systems used comprise of ‘slinky pipes’ which are coiled pipes installed  horizontally and laid along the bottom of the trench. Trenches are generally spaced 5m apart to enable the natural replenishment of energy in the ground. Slinky pipes do not reduce the amount of area required, but they do reduce the the length of trenches required by a factor of around 5. Every 1m of trench contains around 5m of slinky pipe.

Alternatively, straight pipes can be used as an alternative to slinkies, but require more trench work to achieve the same energy harvest.

The exact calculation depends on ground conditions, but approximately for every 60m of pipe 1 kilowatt of energy can be typically absorbed from the ground.

If space is a challenge, a borehole to fit a vertical ground array can be used. In a constrained garden space, a borehole will typically need 150mm width and are typically drilled to a depth of 60m to 200m. Generally boreholes are used for district heating systems for apartment blocks, housing projects or a holiday lodge complex.

There may be instances where the fabric of the building can be improved to achieve the highest levels of efficiency from the heat pump. For example where the property can be updated with the basic thermal improvements i.e. cavity wall installation, loft insulation and double glazing this should be considered if not already installed.

The air source heat pump then needs to be able to meet the maximum heat demand of the property under its maximum (coldest) conditions. Accredited Installers for the domestic market and consultants for the commercial properties can all assist with heat loss calculations to ensure the heat pump matches the building load.

According to the Energy Saving Trust, a Ground Source Heat pump will reduce CO2 emissions per year by between 3t to 4.7t compared to an oil system, 2.8t to 4.5t compared to LPG and 2.1t to 3.3t compared to a gas fired heating and hot water system.

Contact Us

We’d love to hear from you, please use the form below to get in touch: