Performance comparison between direct and combined solar drying with underfloor heating

Solar drying is a highly feasible and economic system, but this process applied for different products can be interrupted during cloudy and rainy days, as well at night. This paper represents a study of the drying process using a direct and a mixed solar dryer with forced convection and a comparison of their respective performances. For this purpose, a heat transfer study of a combined solar dryer will be presented in detail. Then, a performance comparison between the combined solar dryer and the direct solar dryer will be conducted in order to show the advantages of combined dryer in terms of decreasing drying time of the product dried. At the end, the simulations will highlight the enhancement of performance of the combined drying system and will show the positive impact of adding a floor heating system to the direct solar dryer.