The SCI and Oxford Brookes University have recently completed a Partners in Innovation project with Corus and Warmafloor to investigate the use of water cooled slabs in steel framed buildings.
The project demonstrated that this form of cooling is a viable alternative to conventional forms of cooling for commercial buildings. The preferred method is a cooled exposed ceiling, and modelling has demonstrated that heat loads of up to 60W/m2 can be absorbed when the surface is cooled to 20 degrees C.
Water cooled soffits can use free cooling from either cooling ponds or boreholes. As a 'high temperature cooling system', it can use reversible heat pumps, which can then supply background heating when required.
Concepts have been developed which will enable cooling pipes to be laid over steel decking prior to pouring of the concrete, thus making this type of cooling possible for steel intensive construction. Pre-cast units are now commercially available with pipes already embedded.
Economically, the system is extremely competitive. It is cheaper to install than air systems, and operating costs will be much lower because of lower maintenance costs and lower energy use. Simulation showed that water cooled slabs use approximately 20 percent of the energy of a fan-coil system in the same building.