Abstract

Three evaporative cooling (EC) systems viz., mud pot in pot, almirah cooler, coir pith cooler were designed, developed and fabricated at Indian Institute of Horticultural Research (IIHR), Bangalore and the performance was evaluated during winter season. The almirah cooler and coir pith cooler were fabricated using MS angle 60 x 60 x 60 cm and partition was made vertically for every 15 cm height. Two water troughs were designed and made up of GI sheet, one which was kept on the top of the EC system and another at the bottom to collect the water. Different insulation materials viz., sand, jute cloth, coir pith were used to know the performance of EC systems. Temperature and relative humidity are the two major factors which have direct influence in controlling the respiration and transpiration rate of the produce, the data logger was kept both inside and also at ambient to measure the temperature and relative humidity and the data were recorded. It was found that in coir pith cooler there was considerably lower temperature (3-40C) with higher relative humidity (20-30%) along with this the shelf life of the vegetables increased comparatively to other EC systems. The almirah cooler with coir pith insulation system appeared as the best system and can be used to extend the shelf life of the produce.

Keywords: Evaporative cooling, Relative humidity, temperature, physiological loss weight (PLW)