The use of a thermal diode bridge for passive temperature control in the built environment during the heating seasons – An analytical study

The utilization of solar energy to maintain a stable and comfortable air temperature in the built environment has opened up many opportunities for energy saving. However, the periodical nature of the sunlight intensity introduced extra difficulty in the utilization of solar energy. In this paper, a novel concept of jointly using a thermal diode bridge (TDB) and phase change materials (PCMs) was proposed to continuously control the air temperature in built environments during the heating seasons. During the daytime, the solar energy was efficiently harvested and stored in the PCMs, so the indoor temperature was significantly reduced; at nighttime, the thermal energy stored in the PCMs could be used for space heating without heat loss to the outdoor through heat convection. Because of the existence of the TDB, the heat flux going through the building envelope could be passively controlled. An analytical study to evaluate the operating performance of applying such TDB to controlling the zone air temperature in a built environment was carried out and the results were presented. It was demonstrated that the zone air temperature variation in the built environment was significantly reduced, without any electrical energy consumption and greenhouse gas emission.