Assessment of Evaporative Cooling System for Storage of Vegetables

An evaporative cooler was developed and assessed with locally available materials. The materials were outsourced and constructed locally within the study area. A daily monitoring of temperature and relative humidity for both ambient and the cooler were recorded using the wet bulb and dry bulb thermometer and digital humiditytemperature meter. The weight loss was measured using a digital weighing balance. The performance of the evaporative cooler was evaluated in terms of drops in temperature, weight loss and increased relative humidity and evaporative effectiveness. From the results it showed that the evaporative cooler can lessen the daily maximum ambient temperature, the average temperature inside the cooling chamber varied from 20 to 23.50C while the ambient air temperature varied from 25 to 280C for tomatoes and an average of 20.5 to 26.50C inside the cabinet while the ambient air temperature was from 28 to 30.50C for hot pepper. The mean relative humidity of the cabinet during the period of the experiment was about 51 to 93 %, respectively, while the mean relative humidity of the ambient environment was from 47 to 58 % for tomatoes, and the mean relative humidity for hot pepper was from 49 to 95 % of the cabinet and the mean relative humidity of ambient was from 47 to 57 %. The effectiveness of the evaporative cooler was higher during the day between the periods of 12 -14 hrs. local time when observed. The evaporative cooler was able to preserve freshly harvested tomato and hot pepper for 8 days before color changes and mold spotting appeared and the weight was drastically reduced.