The atmospheric temperature in arid zone is always higher and relative humidity is low, which leads to loss of moisture in fruits and vegetables. Fruits and vegetables are perishable commodities with low shelf life. The electricity charges are very high if refrigerators are used for cooling to these foods.
Therefore the design of passive cool chamber has been improved by increasing the evaporating area. It consists of a double walled system having inner and outer chambers made of baked bricks. In both chambers bricks are stacked in vertical walls and have been joined together with cement plaster. The inner chamber is surrounded by outer chamber and coarse sand is filled between the two. The water is also filled between the annular space of inner and outer chambers. A temperature reduction of 12-14°C during summer and 7-9°C during winter was observed with RH varying from 85-95%. The vegetables were safely stored for 7 days in winter and 4-5 days during summer without any spoilage loss. A large size cool chamber costs about Rs. 7000, which can keep fruit and vegetables fresh fetching good market value besides reducing the spoilage.
Surendra Poonia, A.K. Singh, Dilip Jain
and Priyabrata Santra