Exhibits in Liskeard & District Museum are protected by close-controlled underfloor heating system

An underfloor heating installation designed and installed by Stove Shop is protecting exhibits at Liskeard and District Museum. Different, accurately controlled temperatures are needed to preserve the types of exhibit in each room, which include ancient documents, old photographs, delicate fabrics and artefacts in metal and stone. It is also important to slow down the drying of lime mortar, which was applied to the stone walls during building renovation and allows the stone to ‘breathe'.”

Temperatures are controlled precisely in each room by a system specially designed by Stove Shop experts. Each zone is controlled through zone valves by a Honeywell time/temperature programmer linked to an unobtrusive sensor in the room it serves.

The heating system was praised by the museum's Honorary Curator Heather Medlen and other staff, while the project's building surveyor Bernard Wooster wrote: “I am delighted with the new underfloor heating system installed by The Stove Shop. It provides excellent ‘all round' heating, easily controllable in zones to suit the particular requirements of the various display areas, and of course the lack of radiators gives complete freedom in the layout of the exhibits and display cases.”

Stove Shop installed a 60,000 btu/h gas condensing boiler from Ideal for the underfloor heating and a 30,000 btu/h Baxi high efficiency boiler with a Telford Tornado cylinder store supplying hot water taps. It also installed pipe work, central heating manifolds and a hot water storage cylinder.

In addition to its versatility and accuracy of temperature control, the underfloor heating system is exceptionally efficient to reduce fuel consumption, while the architect imposed strict limitations on the components visible in the public areas.

The eleven Honeywell time/temperature controllers are mounted together in the museum boiler room and linked to the Honeywell remote sensors. This eliminates the need to hide bulky components within boxes in public rooms and enables all adjustments to be made conveniently from the boiler room, as the manifolds for the eleven heating zones are also mounted there.

Two Honeywell programmers are mounted on the same control board to switch the boilers.

Stove Shop recognises that underfloor heating manufacturers specify a single boiler for heating and hot water, usually of 100,000btu/h. But its experience of installing such systems is that they operate inefficiently due to running at 70-80 degrees C to satisfy washing needs, so the boiler is not condensing for much of the time. So Stove Shop decided to use a separate boiler to provide hot water to the museum's kitchen and washrooms – a very cost-effective solution as it calculated the second boiler paid for itself in thirty months through fuel savings.

The hot water boiler's efficiency curve shows it needs to run almost flat out for short periods of time to work in its high efficiency portion. This has been achieved, as it runs for just a few minutes each day to satisfy needs.

The underfloor heating boiler therefore runs at a lower temperature, 60 degrees C. This ensures a cool return that keeps it condensing all the time – and therefore operating at maximum efficiency.