Mr Charman’s farmhouse is located in a rural hamlet near South Molton, North Devon. A pre-1900’s stone building, over 287 sqm using oil with radiators. The detached six bedroom farmhouse has plenty of land which made him consider switching from oil to ground source heating. Ken did his research properly before choosing an installer.
South West Heat Pumps got involved in renewables over 17 years ago, working on English Heritage properties. Understanding heat loss calculations and design parameters for older properties and actually having completed installs that worked gave Mr Charman confidence in our ability to deliver a ground source system. He even shared the design with a friend who had a PhD in renewables from Cambridge University who independently reviewed the proposed system and gave it the green light.
The existing oil fired system was swapped to a ground source heat pump. We recommended an IDM Terra 26kW Twin three phase Ground Source Heat Pump with almost a kilometer of ground array laid under the paddock to the rear of the property. We upgraded radiators in over 16 rooms to run at a constant low flow temperature, an economical way to heat a large stone property. The plant room equipment was housed externally in a purpose built shed meaning no internal space was lost. When combined with a 7.75kW solar pv system to offset the electrical costs; the system easily out performs oil based heating.
The system has been installed for almost eleven years and is still serviced annually by South West Heat Pumps. The house, heated with radiators sized to suit every room, holds a constant, even warmth throughout. All six bedrooms stay comfortably heated, and the hot water tank is large enough that a six-bedroom household has never run short, even with sustained demand.
Mr Charman’s advice
Do your research. Ground source works for older houses. Pay a little more for a system as it lasts 20-30 years so use the best people rather than go with the lowest price as the pay back is worth it.


