Combi storage boiler powers efficient, off-grid underfloor heating
Efficient and effective off-grid heating system
Based at Breighton Airfield, Yorkshire, the Real Aeroplane Club exists to promote the flying of historic and home-built aeroplanes. Its members own and operate many unusual, classic and ex-military aircraft.
When the organisation built a new clubhouse to enable it to stage international aviation events at Breighton, it needed an efficient and effective off-grid heating system that closely mapped the building’s usage patterns.
The Solution
In keeping with other buildings at this Second World War Royal AirForce base, the new clubhouse is a single-storey prefabricated steel building. Its architect originally proposed a traditional heating system with radiators and a combi boiler. However, Ashley Thorpe of plumbing and heating innovation experts Thorpe Eco Ltd recommended a floor-standing 19 kW Viessmann Vitodens 222-F combi storage boiler with under-floor heating as a more economical and efficient way to uniformly warm the spacious open-plan area.
The highly modulated boiler, which runs on LPG (liquid petroleum gas) because the site is not connected to the gas main, is set to operate on a timer. With Viessmann’s weather compensation controls installed, it accurately adjusts its operation according to the outside temperature. It also consumes very little power and is extremely quiet, thanks to its high efficiency pump. Almost a mile of under-floor heating piping runs under the floor of the clubhouse to support building-wide comfort from the low temperature system.
“This was the most efficient system we could design using LPG,” explains Thorpe. “The entire heating circuit is run at a maximum of 40oC degrees, or lower when the weather allows. This is well below the normal 60oC flow temperature required for radiators to work efficiently, and it has brought the club’s heating bills and emissions right down. We did discuss the possibility of using an air source heat pump. However, because members of the Real Aeroplane Club are big fans of the combustion engine, they were keen to go down the gas boiler route.”
Located in a small plant room, the space-saving boiler also provides hot water for the toilets, bar and kitchen area. Its enamelled loading cylinder has a capacity of 100 litres, although draw-off performance is comparable to a 350 litre hot-water cylinder installed adjacent to the boiler. The water heated to the required temperature continually charges the loading cylinder and is therefore immediately available.
The new system went into operation in November 2022 and club members have been very impressed with it. “We’ve had four or five new business leads from members for their own projects since the installation,” says Thorpe. “Considering this is quite a small community, we’re really happy with that.”