Design And Development Of An Evaporative Cooling System For Fresh Fruit And Vegetable Storage

ABSTRACT

An evaporative cooling system was developed with locally available materials. The system was aimed at providing lower temperature and higher relative humidity necessary for extending the shelf life of fruits and vegetables. The performance of the cooler was evaluated in terms of temperature drop, humidity gain, cooling efficiency and quality assessment of the stored products. Two categories of test were carried out on the cooler with the chosen absorbent materials: the no-load test and the load test. At no load, the evaporative cooler maintained a temperature reduction of 30% and humidity increase of about 200% compared to the Ambient Conditions. The ambient lost about 77% by weight of fluted pumpkin leave in three days but the Evaporative Cooling System lost that same amount in seven days. Okra lost about 33.4% by weight in seven days in Evaporative Cooling System but almost that same amount in the first day in Ambient Condition. Also Garden Egg lost about 6.83% in seven days in Ambient Condition. Carrot lost 7.4% by weight in Evaporative Cooling System in four days that same amount was lost in first day in the Ambient Condition. The statistical analysis of the result of the experiment on the effect of pad thickness on the efficiency increases as the pad thickness increases, but beyond a pad thickness of 12mm, there is no significant increase in the efficiency. The shelf life of fluted pumpkin, okra, garden egg, and carrot were extended by five days, nine days, fourteen days and twenty one days respectively relative to ambient storage.