A New Mode of a Natural Convection Solar Greenhouse Dryer for Domestic Usage: Performance Assessment for Grape Drying

It is known that the natural convection (NC) solar drying process a simple and cheap method for foodstuffs, but it not preferable common users in case of high-moisture content agro-products due to slow rate drying. Meanwhile, forced (FC) most appropriate such products, its economic feasibility may be affected high initial maintenance costs. Therefore, present study proposed controlled (CNC) mode using greenhouse dryer (SGD) grapes with two types cover materials, glass Plexiglas, through intermittent operation PV system save energy as inexpensive domestic instead SGD conventional SGD. The obtained results new CNC Plexiglas showed higher than NC are close FC same material. moisture was reduced from 5.91 g water/g dry matter final 0.15 within 12 h 15 modes, respectively, Moreover, thermal efficiency mentioned modes 12.5 9.7%, respectively. Page model found predict kinetics all regardless type. achieved lowest cost per kg dried (1.26 USD/kg), highest total saved costs over lifespan (USD 245.46) shortest payback period (1.08 years) compared other dryers, NC-SGD FC-SGD. Generally, CNC-SGD had good performance because by fluctuation volume, velocity direction inlet ambient air/wind during product without external heating sources or complicated parts. Thus, has advantage terms simplicity, cheapness saving