Ground loop in the lake on Norfolk Broads

Finn Geotherm have installed an innovative ground source heat pump system at a detached house in The Broads, Norfolk. The system harvests energy from the homeowner’s lake for heating and hot water.

With a half-acre lake in the garden, the new heating system for the five-bedroom house near North Walsham utilises the property’s natural assets and negates the need for fossil fuels.

“My existing oil boiler needed replacing,” explained homeowner John Sawyer. “With no gas in the area, I was looking for a sustainable, cost effective solution. I did a lot of research into various heating options and found ground source was ideal, particularly as I could use the lake in my garden to house the ground loop.”

Finn Geotherm specified and installed a Lampoassa Vmi 14 ground source heat pump connected to two 250 metre sections of ground loop arranged in slinky coils and submerged in the lake, which is 50 metres from the house. A 480 litre Lampoassa TV thermal store supports the central heating, with the ability to supply 240 litres of domestic hot water in one delivery. The system also has the capability to produce an additional 125 litres of hot water if needed – for example, when guests are staying – which is stored in an unvented cylinder. In everyday circumstances when the extra hot water is not needed, the unvented cylinder is isolated from the main system to conserve energy.

With homeowner John often working from home, the system is ideal as it ensures the house is warm throughout day. In addition, as an IT professional, having the heat pump linked wirelessly to John’s router is another benefit, giving him control over his heating from anywhere in the world.

John Sawyer said:

“I wanted a system which could easily meet our current demands but also had the capability to cope with any future extensions to the property. The heat pump system is ideal for our requirements – it’s both sustainable and cost effective and the house is always warm. We’ve had the wood burner alight once since the ground source system was installed – and that was just for aesthetics as we had people coming over! Finn Geotherm provided us with fantastic service and were extremely knowledgeable, which was very reassuring, especially with a more bespoke project such as ours which used the lake.”

The installation is benefitting from the government’s seven year Domestic Renewable Heat Incentive (RHI) scheme, a government financial incentive which rewards people for opting for renewable heating.