Parametric analysis and annual performance evaluation of an air-based integrated solar heating and radiative cooling collector

Given the disadvantaged seasonal adaptability of solar air heaters and radiative air coolers, this study proposed an air-based integrated solar heating (SH) and radiative cooling (RC) collector (SH-RC collector). Such dual-function collector is capable of obtaining heat in SH mode and gaining cooling energy in RC mode. Accordingly, an air-based SH-RC collector can offer hot air during cold and harvest seasons and provide cool air during hot seasons. A spectrally selective plate termed as TPET collecting plate was trial-manufactured, serving as the panel of the air-based SH-RC collector. Also, this study developed a mathematical model and investigated the SH and RC performances of the proposed collector on a fine summer day. As the results suggest, the average thermal efficiency of the collector in SH mode reaches 45.88%, and the average cooling power of the collector is 36.61 W/m2. Parametric studies on the effect of various ambient temperatures, inlet air temperatures, air flow rates, relative humidity values, and wind velocities on the SH and RC performances of the collector have been conducted. In addition, the monthly energy gains of the air-based SH-RC collector were calculated. The annual heat and cooling gains of the SH-RC collector reached 2328.45 and 980.43 MJ, respectively.