Simulation of thermal-radiating wall with hot water coils partly paved and the influence of installed area size on thermal comfort

The wall radiating heating system was studied, and a conception of hot water coils partly paved in the wall is presented. A heat transfer model was established to simulate the thermal performance of the wall by Fluent. The average heat flux, temperature and temperature distribution of the thermal-radiating wall under unsteady conditions were analyzed. The influence of installed area size on indoor thermal comfort was also analyzed. The results show that when the temperature difference between inlet and outlet water is 5 ℃，rate of flow is 03 m3·h-1, tube spacing is 250 mm, and the area of partly paved coils is 2/3 of the fully paved area, PMV(predicted mean vote) is -028, PPD(predicted percentage of dissatisfied) is 7%, the values are in the range of thermal comfort; when the proportion reaches to 5/6, PMV is +014 and PPD is 5%, the indoor thermal environment is the most comfortable; while when the wall is fully paved, PMV is +05 and PPD is 10%, indoor thermal comfort is reduced. The wall with hot water coil partly paved can economize on materials in comparison with a fully paved wall, and it can save energy effectively while delivering themal comfort.