Experimental study on the thermal performance of radiant floor heating system with the influence of solar radiation on the local floor surface

In some buildings with radiant floor systems for heating, solar radiation can irradiate the local floor surface, causing overheating and affecting the heating performance of the radiant floor. In this paper, an experiment was carried out to study the thermal performance of radiant floor partially irradiated by solar radiation. Results show that the solar radiation can promote the heat transfer from the irradiated floor to the room and reduce the heat transfer from the hot water to the floor. Compared with the cases without the solar radiation, the heat transfer from the hot water to the floor was reduced from 131.8 W/m 2 to 79.7 W/m 2 and the heating capacity of radiant floor surface was increased from 128.0 W/m 2 to 402.8 W/m 2 with the solar radiation on one third of the floor surface and the absorbed intensity of 456.2 W/m 2 . With the same irradiation area, if the solar radiation irradiated at the centre of the floor, the reduction effect on the heat transfer from the hot water was more obvious. Based on this experiment, these results can be used to evaluate the thermal performance of irradiated radiant floor, and are beneficial to the design of heating systems.