Experimental Assessment and Modeling of Radiant Cooling Technology Using Constant and Variable Water Flow Rate

The goal of this study is to perform an analysis of the performance of radiant cooling panels using experimental testing and transient system simulation software. The effect of design parameters such as water supply temperature and water flow rate on thermal comfort and energy efficiency is studied. Two control schemes are used in the study in which either the water flow rate or the water temperature difference between the inlet and outlet of radiant panels is held constant. This paper demonstrates the modeling and validation of a radiant cooling system in TRNSYS and uses this model to study the performance of the system during the cooling season in Egypt. It was found that the lower water temperature of 16 degrees C was found to be suitable for achieving thermal comfort. The constant water flow rate control scheme showed a 5% less unmet hours percentage than the constant water temperature difference, but the latter used 38% less electrical energy. A constant water temperature difference control scheme can achieve better thermal comfort with an unmet hours percentage down to 12.5% by coupling the system with a dehumidification device.