Thermal Performance of Solar Air Heater with Porous Material

This paper presents an experimental thermal performance of flat plate solar air heater with and without porous material. The steel wool was selected as porous materials for this work. The solar radiations was simulated by halogen lights and dimmers and variac were used for regulating intensity. The couple of solar air heaters were constructed for with and without porous material. The experiments were conducted on both of solar air heaters at same location, simultaneously. The experiments were carried out the following conditions: solar radiation of 400, 600 and 800 W/m(2), air mass flow rate of 0.01, 0.015 and 0.02 kg/s and porous material which having porosity of 0.92 and 0.94. The criteria to comparatively study of the thermal efficiency of solar air heater with and without porous material. The experimental results revealed that temperature difference between inlet and outlet of solar air heater increased with increment of solar radiation. Furthermore, the thermal efficiency of solar air heater having porous material was higher than solar air heater without porous material. Thermal efficiency of solar air heater was increased with air mass flow rate increased. In addition, the thermal efficiency will be enhanced because of increasing of heat transfer area due to porous material.