Thermal performance regulation and optimization for rooms of residential buildings via using radiative cooling and solar heating system

Abstract

Window system aways has the worst performance in terms of the building energy saving, which needs to be optimized. In this work, a radiative cooling and heating system was proposed, comprising of a cooling device covered with the radiative cooling film, and a heating device with an enclosed air layer. The proposed system was integrated into the window of a room in the residential building, aiming at improving the indoor thermal comfort. The indoor thermal regulation by the proposed system is a two-step process, to reduce the energy consumption requirements. In the step 1, the proposed system could create an air temperature buffer zone for the window system, to mitigate the indoor air temperature change. In the step 2, the cooling device and the iron blades in the heating device could provide shadings for the window. Although the heating energy demand at the daytime in winter was increased via installing a louver in the heating device, the iron blades with black color were conducive to gaining more solar heat and adjusting the indoor natural daylighting. Furthermore, the heating device covered the window was helpful for increase in the thermal isolation performance of the glazing envelope. Based on the thermal and daylighting regulations by the proposed system, a total annual energy consumption difference of 795 kW h between the original room and the novel room was realized, leading to an energy saving rate of 16.3%.