Heat Pumps

The process of heat pumps is complex, however fundamentally they extract heat/energy from the ‘source’ location, which is converted and upgraded for central heating. The source can be ground, air or water, though ground and air are more common as they can be accessible to most. Water source heat pumps require a water source that does not freeze during the winter months.

Air source heat pumps

Air source heat pumps extract heat through a fan. There are air-to-water systems used for hot water systems, or air-to-air systems for space heating, though this is less common in the UK.

They can be installed outside the building, with services connected through the wall. This can have an adverse visual impact, which may need to be a consideration with designated heritage assets. Mitigation can take the form of an appropriately design enclosure. The heat pumps can also be installed internally with the fan for the air source, connected through the wall. Whilst this has less of a visual impact externally, generally they can take up more space internally, and therefore may not be an option for smaller buildings. The routing of services should also be sympathetic.

Ground source heat pumps

Ground source heat pumps extract heat via pipes inserted into the ground and connected to a building. Burial of the pipes is either through a closed loop system, that requires trenches, or open loop systems, requiring boreholes. Large drilling machinery is required for the installation, and this can be disruptive. Archaeological sensitivity may also need to be considered in some areas.