This new build is set in a rural area and has been constructed to a high standard of insulation and airtightness. It is heated by a GSHP linked to underfloor heating with a triple coil unvented cylinder supplying DHW.

The main components of the heating and hot water system are a NIBE F1145 heat pump and a 40-tube solar thermal collector linked to a 300 litre unvented hot water storage cylinder. The heat pump sources energy from a ground collector consisting of a two radial boreholes connected to a header manifold.

The solar thermal collector is sized to provide over 70% of the estimated annual domestic hot water usage. To protect against overheating in summer, the solar circuit includes a bypass radiator through which excess heat is dissipated.

To enhance the solar contribution and minimise use of the heat pump the storage cylinder includes two solar coils, in addition to the heat pump coil. Heat is initially directed to the upper coil; when the upper cylinder reaches its target temperature further heat is diverted into the lower coil.