Design and thermal performance evaluation of a novel solar air heater

In the present scenario, numerous applications perform on solar energy for cooking, heating and cooling, and power generation, globally. Solar air heaters are one of these applications purposely used for, drying, timber seasoning and space heating. In the present work, a solar air heater (SAH) has been designed to produce a good exhaust temperature for long hours especially in the case of poor ambient conditions or during off sunshine hours. A mixture of desert and granular carbon in the ratio of 4:6 has been used as thermal heat storage inside the SAH. Two halogen lights of 300 W are used to increase the exhaust temperature of the SAH by placing them in the inlet and outlet ducts. All the experiments have conducted on natural and forced convection for performance evaluation on two similar design solar air heaters (with and without heat storage). The comparisons are made with two similar design solar air heaters carrying desert and granular carbon, as an individual heat storing media, to find out an optimum design of a SAH with long term heating. The thermal efficiencies of the novel SAH range from 18.04% to 20.78% of natural convection and 52.21%-80.05% with forced convection.