Development and validation of a versatile method for the calculation of heat transfer in water-based radiant systems

The description of the thermal behaviour of radiant systems is complex due to the 3D heat transfer and the relevant thermal inertia characterising the active surface. As a consequence, it is necessary to define modelling simplifications in order to achieve a reliable forecast of the thermal field inside the structure and, hence, of the heat exchange between the active structure and the room. This paper presents the whole process performed within the development of a calculation module integrated within software BSim (www.bsim.dk, by the Danish Building Research Institute) for the description of radiant systems. The present work started with the examination of existing calculation models for radiant systems. Then a model with further extensions was implemented and tested. Such a module is able to cover a wide range of cases with just one calculation tool. In the end, it was tested against field measurements in a climatic chamber at the Danish Technical University, Lyngby (Copenhagen).