Energy-saving Operation and Optimization of Thermal Comfort in Thermal Radiative Cooling/Heating System

The energy-saving operation in the thermal radiative cooling/heating system has been verified. The coefficient of performance (COP) has been experimentally evaluated by changing the water temperature and the flow rate to control the heat amount. The energy-saving operation has been achieved by increasing the flow rate for the same heat amount. The thermal comfort has also been evaluated by calculating the predicted mean vote (PMV). In the case of the energy-saving operation, it is expected that the heat amount by radiation is reduced and impair the thermal comfort. However, it is found that its reduction has a small effect on the thermal comfort.