Fruits and vegetables readily spoil immediately after harvest due to their highly perishable nature. Unfortunately, energy-efficient storage facilities are not available or not within the reach of small holder farmers. Conventional evaporative cooling systems (ECS) have gained popularity as a costeffective and energy-efficient method for the shorttime storage of perishable produce. However, conventional ECS sometimes requires frequent manual intervention and water refilling which might impede their efficiency, reliability and scalability for smallholder farmers. A mixed method was used to identify this gap. An automated evaporative cooling system was designed, developed and tested to evaluate its performance for the storage of agricultural produce. The ECS consists of the storage chamber and a micro-controller-based instrumentation unit for measurement and data collection. The Microcontroller (ESP 32) was interfaced with digital temperature and humidity sensors (DHT 22), Load cells HX711, RTC, 12C LCD. The entire system was powered by a 2.0 kVA inverter, a 165 W solar panel and a deep-cycle battery. The microcontroller-based instrumentation unit measured temperature, relative humidity and weight of produce stored both in the ECS and under ambient conditions at predetermined intervals. The results indicated that the temperature within the ECS was consistently lower than the ambient temperature, while the relative humidity inside the ECS was higher. Furthermore, produce stored under ambient conditions exhibited greater weight loss compared to those stored in the ECS. The high cooling efficiency and reduced weight loss observed in the ECS shows that the automated system performed effectively in extending shelf life and minimizing post-harvest losses of the stored produce.
Metiboba et al. (Mon,) studied this question.