Designs, Performance and Economic Feasibility of Domestic Solar Dryers

Present article is an overview of available solar drying technologies developed for small rural agricultural farms emphasizing domestic applications. A huge amount (about 61%) of perishable items gets wasted annually at the household level due to lack of awareness, negligence, improper handling, and inadequate storage facilities. Domestic solar dryers are reviewed and presented under the categories of natural and forced convection modes. The maximum attainable temperature inside the drying chamber under natural and forced convection mode is observed 98.6 and 78.1 degrees C, respectively. Thermal efficiency of solar dryers varies from 5.16 to 64.36% for the drying of various commodities. Natural convection solar dryers are appropriate for rural and undeveloped areas due to simple design and lower capital and electrical requirements. In comparison, forced convection solar dryers are more attractive due to better performance, higher drying rate, and lower drying time for high moisture content products. The designs of indirect and mixed-mode solar dryers seem very rare in the area of domestic solar drying. Solar dryers have potential to reduce the conventional drying cost by 50% and improve the return by 30%.

Automated summary

This article provides an overview of solar drying technologies for small rural agricultural farms, focusing on domestic applications. A significant amount of perishable items are wasted annually at the household level due to various reasons. The article reviews and presents natural and forced convection solar dryers, highlighting their temperature and thermal efficiency. Natural convection solar dryers are suitable for rural areas due to their simple design and lower requirements, while forced convection solar dryers offer better performance and faster drying time for high moisture content products. The designs of indirect and mixed-mode solar dryers in domestic applications are rare. Solar dryers have the potential to reduce drying costs by 50% and improve returns by 30%.