Monitoring and simulation of two operational buildings integrating active thermal mass strategies

Thermal mass can be used in buildings to reduce the need for and dependence on mechanical heating and cooling systems whilst maintaining environmental comfort. Active thermal mass strategies further enhance the performance of thermal mass by integrating it with Heating, Ventilation and Air Conditioning (HVAC) systems. In this paper two buildings in the UK incorporating different active thermal mass strategies have been monitored for a summer period. The first, a classroom in an education building, uses hollow core concrete floor slabs to distribute the ventilation supply air to the occupied space below. The second, a training/meeting space in an office building, uses the void created by a raised floor and the structural concrete floor slab as a plenum to supply ventilation air to the occupied space above. The monitored data has then been used to develop a dynamic thermal computer model of both strategies. To determine the performance of the two strategies the comfort within the occupied space, together with the energy and carbon emissions of the strategy have been modelled and analysed in comparison to the performance of the building had it been of standard construction. Improved control strategies for each system have then been developed to fully integrate the HVAC system with the buildings thermal mass.