Ground Source Review: Orchard House.
Ben Turner decided to have a 15kW Kensa Hybrid Twin ground source heat pump installed to provide heating and hot water to his home on a working farm in Somerset.
Tagged in: Case Studies
Ground Source Review: Orchard House
Ben Turner and his young family live in Orchard House, a barn located on his parent’s working farm in Somerset, converted in the mid 2000’s. Working for Natural England, a public body advising the Government on the protection of the UK’s natural environment, Ben was keen to generate all of the heating, hot water and electricity that his home needed from natural, sustainable resources.
He approached Devon-based installer and Kensa partner Source CHP, who have a wealth of experience across a number of different renewable technologies, including ground source heat pumps. The system designers at Source CHP worked with Ben to agree a solution that would meet his needs and provide the maximum return on his financial investment. They recommended installing a Kensa ground source heat pump to provide 100% of the barn’s heating and hot water requirements, combined with a solar PV system to provide additional electricity.
The four bedroom barn measured 240m² with a heat load of 13.1 kW, so Kensa recommended a 15kW Hybrid model - perfect for large, well-insulated, retrofit properties - to provide efficient space heating and high hot water temperatures required by the existing heating system. Source CHP installed the unit outside the house in a specially created structure, along with a 305 litre unvented stainless steel domestic hot water cylinder.
Ben identified some spare land nearby which was ideal for harnessing the heat energy needed for the ground source heat pump. He worked alongside Source CHP to plan the positioning and number of trenches, but Ben had the appropriate machinery and relevant ground working experience to dig the four required trenches himself to save on installation costs.
Source CHP then installed 50m of coiled slinky pipe into the trenches to extract heat from the ground, before connecting the underground manifold and flow and returns back to the heat pump. On Ben’s request, Source CHP also installed a power and water supply part way down the garden using the existing trench.
The ground source heat pump system was integrated with the barn’s existing heating system which included radiators and underfloor heating. Underfloor heating works especially well with ground source heat pumps as it ensures a low floor temperature and allows the heat pump to operate especially efficiently, minimising electricity costs.
The installation was eligible for payback under the Government’s Domestic Renewable Heat Incentive (RHI) scheme. The RHI payment that Ben will receive is around £3,500 in the first year, and he will continue to receive, index-linked quarterly payments for seven years. The payments alone will more than cover the installation costs, plus, Ben will save almost £900 a year in fuel costs compared to oil for the life of the system.
Providing Ben with further self-sufficiency, Source CHP installed a 6kW solar PV array on the roof of the barn. The set up generates electricity throughout the day, supplementing the electrical use of the ground source heat pump and providing an additional source of income through the Feed-in-Tariff.
Source CHP were able to support Ben with the commissioning of the ground source heat pump and provided a full system handover leaving him comfortable with the running of the system. They also supported his applications for the Renewable Heat Incentive (RHI) and the Feed-in-Tariff.