A ground source heat pump (GSHPs) uses pipes which are buried in your garden to extract heat from the ground, generated by both sunlight and rainfall. The ground stays at a fairly constant temperature under the surface, so the heat pump can be used all year round. There are two common types of heat pump used in heating systems, Air Source and Ground Source.

A GSHP is electrically driven and utilises a refrigerant cycle, similar to an air source heat pump but extracting heat from the ground. This heat is absorbed at low temperatures into a fluid inside specially installed pipes buried underground. The fluid then passes through a compressor which raises it to a higher temperature, ready to be delivered to your heating and hot water systems.

GSHP’s are generally more efficient than air source heat pumps. GSHP’s utilise the earth’s relatively constant temperature, which is warmer than the average air temperature, particularly in winter, leading to higher efficiency. Air source heat pumps rely on the air’s fluctuating temperatures, which can make them less efficient, especially in cold weather.

• Efficiency: can be up to 50% more efficient than air source heat pumps due to the more consistent and warmer ground temperature. They can deliver more heat for the same amount of electricity consumed.
• Cost: they have higher initial installation costs, but they can lead to lower running costs due to their higher efficiency. Air source heat pumps are generally cheaper to install but may have higher running costs, especially in cold climates.
• Performance: they are less affected by weather changes, providing consistent performance throughout the year. Air source heat pumps can experience a decrease in efficiency during colder months.
• Space: GSHP’s require more space for their ground loops or boreholes, while air source heat pumps have a smaller footprint.

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