EXPERIMENTAL STUDY OF AN INDIRECT EVAPORATIVE COOLING SYSTEM FOR PRESERVING PERISHABLE FARM PRODUCE

Abstract

This study was based on the principles of evaporative cooling where warm dry air is cooled and humidified by passing it through a wetted surface (heat exchanger). Based on this study, which was to provide an alternative source of storage for some perishable agricultural products, it can be deduced that the evaporative cooler can be used as a temporary means of storage of vegetables. The newly developed system performed up to expectation as tested samples maintained their fresh condition for the 3days within which they were tested. The required storage temperature for the preservation of the selected vegetable samples was achieved at 16°C for the cabinet temperature at an ambient temperature of about 37°C. The result showed an average temperature depression of 17oC. The cabinet maintained a temperature of below 20oC which was necessary to maintain and preserve the tomatoes. With respect to the quality of the stored items (vegetable, tomatoes samples) results obtained show that there is a tremendous improvement over the mechanical multipurpose refrigerating system. The system developed maintained a higher quality of preservation when compared to the mechanical multipurpose refrigerating system. Hence, the excessive chilling or freezing effects normally experienced  with vegetables  stored  using  the Latter method were naturally eliminated by the operating conditions of the newly developed evaporative cooling system, as the stored products were only exposed to their required storage temperatures. Hence this system can be used for preservation of fresh vegetables with their quality still maintained for at least ten (10) days and more.

KEYWORDS: indirect evaporative cooling, heat exchanger, post-harvest losses, fruits, vegetables