A Review of Solar Air Heater for Drying of Agricultural Products

Bulk of farm products need to be preserved because of their perishable nature. The cheapest and environmental friendly means is indirect usage of solar irradiance to reduce the moisture content of these products to a level that cannot sustain the activities of micro-organisms. The research on solar collector has gained its popularity over the years due to man’s quest for green energy which has led to increase in demand for the utilization of solar energy. Harnessing of solar energy by man for drying purposes was predominantly by direct method which reduces the quality and quantity of the dried products. This work presents the most recent contributionson solar air heater of flat plate absorber category. Various models, material of component parts and performance efficiency of these air heaterswere discussed and there is need for collectoroptimization. The study was concluded with a focus on multiple pass approach of solar harvesting.