Comparison of the Thermal Performance of Radiative and Convective Terminals: A conceptual approach

During the last decades, the use of radiant terminals for heating or cooling buildings has rapidly increased and the activation of different construction elements has been tested: floor, ceiling or walls. Radiant systems are usually used instead of air conditioning systems: it is therefore of interest to compare the energy efficiency of the two types of terminals for heating and cooling buildings. Convective terminals (i.e. air conditioning systems) have been widely used in buildings, but the level of comfort is not always acceptable due to high air velocity. On the other hand radiant terminals can provide a better indoor climate, and be more energy efficient because they can make use of low-grade sources. The output of this conceptual approach is a better understanding of the advantages and drawbacks of the two technologies under different conditions. The analysis has been performed by simulating the energy consumption of an office room, located in Denmark. Different outdoor conditions have been tested, in order to compare their performance during the winter season and the summer season. Different types of activated surface have also been simulated. The results of this analysis show that the efficiency of convective terminals is highly dependent on the ventilation losses of the building. Radiant terminals are less sensitive to this parameter.