Integrating Active Thermal Mass Strategies with HVAC Systems: Dynamic Thermal Modelling

Active thermal mass strategies can be used to enhance the performance of thermal mass through integration with the heating, ventilation and air conditioning (HVAC) systems. Dynamic thermal modelling is required in most cases to accurately determine the performance of its integration with the environmental systems of the building. This paper describes the use of a commercially available dynamic building thermal program to construct models for active thermal mass strategies and compare the results with monitored temperatures in buildings incorporating the strategies in the UK. Four active thermal mass strategies are considered (a) hollow core slabs, (b) floor void with mass, (c) earth-to-air heat exchanger and (d) thermal labyrinth. The operational strategies and monitoring are presented and their modelling is described in terms of geometrical configuration and input parameters. The modelling results are compared with the measured parameters successfully. Using the calibrated model, a simple Excel based tool (TMAir) was developed for concept design analysis; this tool is described briefly and is available in the public domain.