Design of an evaporative cooling system integrated with ultraviolet light for preservation of fruits and vegetables at variable tropical weather conditions: a case study of Arusha, Tanzania

Abstract

Problems with fruits and vegetables spoiling after harvest are particularly acute in tropical regions. This research presents the design, construction, and performance assessment of a solar-powered evaporative cooling storage system incorporating ultraviolet radiation (UV) to preserve foods susceptible to spoilage. Local materials, including sisal, sponge, and bricks, were used to construct the cooling chamber with a UV bulb. We measured the system's efficiency in both sunny and overcast tropical weather conditions by looking at how much air temperature was reduced, how much relative humidity was increased, and how much electricity was used for evaporative cooling. According to research, fruits and vegetables may be kept fresh for much longer after activating the UV light. This method may keep perishable goods for up to 21 days under UV light and 9 days without. An average temperature drop of 5.0℃ and an increase in relative humidity result from active system operation on sunny days. In contrast, the cooling effect is minimal on overcast days, leading to a relative humidity rise of 18% and a temperature drop of around 3.5℃. Based on these results, a solar-powered evaporative cooling system with UV radiation treatment might be a good way to reduce tropical post-harvest losses.