As part of an extensive refurbishment, the equipment supplying heating and hot water for this 3 bedroom detached rural property has been moved into a small external plant room constructed on one end of the building.

We were able to squeeze a Kensa 6kW HT compact ground source heat pump (GSHP), a 260 litre unvented DHW storage cylinder and an 80 litre buffer tank, along with an ice machine and a water softener, into the plant room. The ground collector consists of two 50m slinkies connecting to a 2-way manifold. Additional insulation has improved the energy efficiency and along with underfloor heating on both floors allows the GSHP to be operated at a design flow temperature of 40°C, achieving a seasonal performance factor of 4.1.

We also installed a 3.96 kWp PV array on the south facing roof of an outbuilding. This consists of 12 x BenQ Sunforte 330Wp modules arranged in landscape mode and connected via a SolarEdge inverter with individual powerboxes to minimise the impact of shading from overhead cables. It helps to offset the electricity consumed by the heat pump, both by generating power when the heat pump is operating and financially through FiT payments.

During late spring, summer and early autumn the majority of the hot water requirement will be met by an Immersun PV switch which diverts surplus PV to twin immersion elements in the hot water cylinder, firstly to the top of the cylinder, and subsequently to the lower part of the cylinder.