Rehau’s Awadukt Thermo ground-air heat exchanger has been specified for the Carclaze Community primary school in St Austell, Cornwall

The unit has ben installed on the lower ground floor where natural ventilation was limited. The polypropylene pipework has been laid in a 16 x 30m array 1.5m below the school’s playing fields. Sixteen runs of 30m long, 250mm diameter pipework and 500mm diameter header pipe were installed through which fresh air is drawn, allowing heat transfer to take place between the air and the ground, which is a fairly constant 8-12ºC all year round.

During the winter, this has the effect of pre-warming the air by up to 9ºC and in summer it can be pre-cooled by as much as 14ºC before it is delivered into the building by way of a series of floor grilles. About 3,500m3 of pre-tempered air can be delivered every hour.