Design, Fabrication, and Performance Evaluation of a Low-Cost Double-Glazed Solar Tomato Dryer

Abstract

Post-harvest losses of tomato remain a major contributor to food waste and food insecurity in Nigeria, where inadequate storage and reliance on open-air sun drying leave the crop vulnerable to spoilage and contamination. This paper presents the design, fabrication, and performance evaluation of a low-cost, double-glazed solar tomato dryer intended for small-scale farmers. The system couples a flat-plate solar box collector, tilted at 16.7°, to a ventilated drying chamber holding three mesh trays. Governing equations were used to size the drying chamber, collector, and vent, and a black-coated aluminium absorber with a double glazing arrangement was adopted to limit heat loss. The fabricated dryer was tested with sliced tomato samples under natural sunlight. Collector temperatures reached a peak of 84.1 °C in the early afternoon, and the sample mass fell from 7.97 g to 1.30 g within about six hours, corresponding to an 83.7% reduction in sample mass. The complete unit was fabricated entirely from locally available materials. The results confirm that a simple double-glazed solar dryer can remove moisture from tomato slices quickly and affordably, offering a practical, sustainable route to reducing post-harvest tomato losses in Nigeria and similar high-insolation regions.