Parametric study on the effect of radiant heating system on indoor thermal comfort with/without external thermal disturbance

Abstract

For radiant heating system, less concern has been given to the fact that supply water temperatures are determined according to local conditions, and it is unclear how surface emissivity of the system affects indoor thermal comfort. Therefore, the application of radiant heating system with fixed water supply temperature in two different types of buildings is analyzed. The transient simulation is verified experimentally and the results show that when the radiator area is determined, adjusting water supply temperature has a great effect on thermal comfort. Changing the basic water temperature by 5 °C can reduce the thermal comfort by 20%. Therefore, it is more reasonable to determine the water supply temperature first and then design other parameters, which can improve thermal comfort and reduce unnecessary energy consumption. The radiator surface emissivity changes thermal comfort mainly by affecting the response speed. The higher the emissivity, the better the thermal comfort. However, if only considering the acceptable thermal comfort zone, changing the emissivity will have little effect on thermal comfort. The time proportion of acceptable thermal comfort zone is only reduced by 5% when emissivity changes from 0.95 to 0.5. Therefore, users can choose radiator surface materials more flexibly according to their needs.