Operation and Control of Activated Slab Heating and Cooling Systems

Heating and cooling of buildings may be done by water based radiant systems, where pipes are embedded in the concrete slabs between each storey. Activating the building mass will reduce the peak load and transfer some of load to out side the period of occupancy. Because these systems operate at water temperature close to room the potential for use of renewable energy sources are increased Due to the high energy consumption and first costs several European countries debate if air conditioning of buildings is to be recommended or prohibited by law. Air-conditioning will give better control of the indoor temperature and improve comfort and productivity. However, many examples of discomfort in air-conditioned buildings due to draught, noise and sick building syndrome, exist. Because these types of systems are using building mass for heating and cooling it is often questioned how they must be designed, kind of control concept should be used and what are the performance. The present paper presents a parametric study of design issues and different control concepts, based on dynamic computer simulations. To use these type of systems the building must be well designed. A combination of time control and water temperature control according to outside temperature conditions will provide acceptable indoor conditions and low energy consumption. Several examples of buildings with these type of systems is presented together with measured performance.