Abstract
This study investigates the performance and economic aspects of a novel natural convection solar dryer designed for drying tomato slices. The dryer, featuring a floor area of with a north–south orientation, incorporates an optimally inclined solar collector (OISC). The optimization of the dryer tilt enhances the greenhouse effect within the drying cabinet, leading to increased solar radiation intensity during the drying process. The increased total solar radiation input facilitates a more efficient drying rate by elevating both the internal air and crop temperatures. The selection of the optimal inclination angle for the drying cabinet is performed on a monthly and seasonal basis. The drying experiment is conducted at an inclination angle of 0 deg (fully horizontal surface), 23.18 deg (latitude angle), and 37.5 deg (optimum angle). By using OISC on a monthly basis in the natural convection solar dryer, the solar radiation increases by 22% and 5%, respectively, compared to horizontal and latitude inclinations. Additionally, the internal air temperature rises by 42% and 30% during the drying period compared to the ambient air and bottom dryer temperature, saving 24% of the total drying time. This optimized approach holds promise for enhancing the efficiency and economic viability of solar drying processes for tomato slices.