Castle Howard goes Green by Installing Heat Pump

7th June 2009 Published in The Mail on Sunday
By Jonny Beardsall

At 142,400 sq ft with scant insulation and no double glazing, Castle Howard must be one of the least carbon friendly houses in England. But not for much longer.

Owner Simon Howard is installing the latest ground source heat pump technology in the spring fed pond where the pleasure seeking Sebastian Flyte and his chum, Charles Ryder, flounced about in the lavish TV serial Brideshead Revisited.

He decided that Castle Howard's £20,000 annual heating bills needed to be trimmed.

"Although we'd reduced our yearly oil consumption to 51,000 litres by leaving the boilers running all the time at a lower temperature of 50 degrees, I still wasn't happy,"says the 52 year old.

Then he discovered geothermal energy - where the earth's heat is converted into power.

'It's clean and very green' he says of the complex process that uses solar energy stored naturally at low temperatures both underwater and underground.

After the draining of a 3 acre lake in the stately home's grounds, a spring has been temporarily diverted and several feet of silt removed.

"Although we'd reduced our yearly oil consumption to 51,000 litres by leaving the boilers running all the time at a lower temperature of 50 degrees, I still wasn't happy,"

In the lake bed a coiled pipe containing a continuously circulating mixture of water and anti-freeze is being laid in an area the size of a tennis court, which then connects to two 100kW heat pumps in the boiler in the house.

When the lake refills, the moving water will warm the solution in the pipe by a few degrees by conduction and convection. This energy is transferred to the heat pumps to keep the castle's radiators running at a constant 55^oC.

Anti-freeze prevents the pipes from freezing because solution in the pipes drops below zero on its way back to the lake.

"I don't fully understand how it all works but installing it makes absolute sense," says Howard. "You're not burning any fossil fuel, just a small amount of electricity to run the pump, and for every kilowatt the pump uses, four kilowatts of heat is generated for the home, so, unarguably it has to be the way forward."

With minimal running costs, and largely maintenance free, the pump should last 25 years and, unlike oil and gas, it produces around 50 per cent less CO₂ than a conventional oil boiler.

Pipes can be buried under a field or lawn with equally efficient results, and even if you have only a tiny garden, a borehole can be sunk beneath your patio and heat extracted in the same way, or an air source heat pump can be used.

"I don't fully understand how it all works but installing it makes absolute sense,"

In Sweden, 97 per cent of new homes come with a heat pump built in, whereas in Britain it is still an after thought because, until recently, cheap oil and gas outweighed the initial installation costs.

But according to Gloucestershire based Ecovision, which is installing the technology at Castle Howard, the market is increasing fast. 'This is our first attempt at a major stately home where we"ve installed it in a lake and now we"re in discussions with other estates.' says company Director Dirk van Lennep.