Abstract: Sun drying of agricultural products is the traditional method employed in most of the developing countries. Sun drying is used to denote the exposure of a commodity to direct solar radiation and the convective power of the natural wind. Drying is cheapest and most common method of preservation and storing of agricultural products. It was observed that dryer efficiency continuously changing during drying process due to change in solar radiation and temperature. Performance of solar tunnel dryer is depends upon on different performing parameters. The flow rate, temperature and relative humidity of drying air plays major role in drying. Also moisture content in product, area of collector plate, thickness of polythene sheet, absorbing material and thickness of drying layer are important parameter. The main aim of this project is do the performance evaluation of solar tunnel dryer by varying input performing parameters such as absorber material for collector area flow rate of drying air and thickness of polythene sheet and to determine the output performance parameters such as efficiency of solar tunnel dryer, Time required for drying agricultural product, and cost of solar tunnel dryer.

Keywords: Solar tunnel dryer, Performance parameter, Absorber material, OSD (Open Sun Drying).