Indirect-type dryers present an optimal solution by addressing crop preservation challenges while maintaining their nutritional quality, resulting in increased profitability for farmers. These dryers utilize both sensible and latent heat storage materials for energy retention. Comprising a solar flat plate air collector with a clear glass cover, an insulated drying chamber, and an exhaust chimney, the dryer boasts a cabinet surface area of 0.273 square meters and collector dimensions of 1.62 meters in length, 0.60 meters in width, and 0.36 meters in height. In practice, carrot slices experienced moisture reduction from 90% to 4.6% within 16 hours of drying at temperatures ranging from 41 to 47 degrees Celsius, outperforming sun drying, which achieved a moisture content reduction from 90% to 5.4% over 20 hours at temperatures ranging from 37 to 41 degrees Celsius. Efficiency testing yielded 31.5% with load tests and 65% without load tests for the collector.
Yadav et al. (Wed,) studied this question.