Experimental performance analysis of a novel sand coated and sand filled polycarbonate sheet based solar air collector

Abstract An experiment was conducted to investigate the performance of a novel sand coated and sand filled (SCSF) polycarbonate sheet based solar air collector (SAC) under controlled indoor conditions with variable air flow rates and solar inputs. The performance of this novel absorber was compared with aluminium absorber (with and without sand coating). The results indicated that due to the presence of sand coating over the absorber, the rate of heat transfer was enhanced by redistribution of air flow. Further, the presence of sand within the poly carbonate sheet acted as a thermal heat storage medium that might be used during off-sunshine hours. Further, the increment in mass flow rate by 87% lead to decrement in the magnitudes of stored energy by 10–24% and but the average discharging efficiency was increased by 15%. The maximum thermal efficiency of the proposed collector was found to be 42% during charging. Reduction of air gap from 5 cm to 3 cm resulted in 11% higher thermal efficiency for sand coated aluminium absorber based SAC. It was found that the SAC with storage provided 39% and 20% higher thermal efficiency than that of the black paint coated aluminium absorber and sand coated aluminium absorber, respectively.