The system was installed by Denbigh-based firm Hafod Renewables and has the added benefit of earning owner Zoë Henderson £4,000 ($5,600) a year from the Renewable Heating Initiative.
Caerfallen, just north of Ruthin was built for Robert Turbridge, the Queen’s Surveyor of North Wales, in 1559. The property is now owned by Henderson whose grandfather bought it in 1955.
Henderson, a former businesswoman with Dow Chemical, has transformed the old barn into a beautifully-appointed holiday destination with sweeping views across the Vale of Clwyd.
Central to the air of luxury is the underfloor heating powered by heat generated by the summer sun and stored in the ground in a nearby field where sheep and horses now graze.
Four feet below the grass, water flowing through 600 metres of pipe is heated by the soil’s residual warmth and is fed back into the barn. There in the boiler room is a heat exchanger capable of transforming the winter chill of ground temperatures as low as 4C (40F) to a positively tropical 35C (95F).
David Jones, Managing Director of Hafod Renewables, said, “We have done similar work but this was such a historic property that it was pretty special.
“The system uses the big bank of heat that is built up in the ground by the sun through the summer and which is retained through the year, even in the hardest frosts and snow.”
The 12 kW heating system is part of a major renovation the Henderson family has carried out over the past five years.
Henderson said, “My parents, David and Wendy Henderson, had farmed here for many years but it was time for them to move somewhere warm and the last thing we wanted was to sell the house and see someone else renovate it."
There has been a house on the land since at least 1324 and dendrochronology carried out by Discovering Old Welsh Houses at Caerfallen, date it to 1560, two years into Elizabeth I’s reign. The barn is believed to be from the same period.
The choice of ground source was a no-brainer according to David Jones, an electrician and graduate in renewable energy, who founded Hafod Renewables with his father, Richard, a heating engineer, in 2010.
David said: “One of the beauties of ground source heating for an important listed building like this is that it’s invisible, there aren’t any solar panels on the roof or an air-source system on the wall.
“It’s also silent so you switch it on and forget about it for 25 years while it heats your home and pays you a nice little income.”
