* Deptt. of Agril. Proc. & Food Engg., Orissa Univ. of Agri. & Technology, Bhubaneswar.
** Division of Agricultural Engineering, Indian Agricultural Research Institute, New Delhi.
An analysis was carried out to observe the economic feasibility of evaporatively cooled (EC) storage structures for storage of horticultural produce. Two types of storage structures, one made with brick-sand-brick walls and the other with wood wool pad walls were considered for the analysis. It was observed that in 0.25 m3 EC structures (100 kg capacity) the cost of storage was Rs. 0.07 per kg of commodity per day. Hence, EC storage structures can be advantageously utilised for extending the shelf life of highly perishable commodities to about 6–7 days, which would otherwise get spoilt in 2–3 days under ambient storage conditions. However, for semiperishable commodities like potato, the cost of storage for a period of 100–120 days would be about Rs. 7.001 kg. Therefore, under this situation, the small capacity EC structures do not offer any economic advantage over the ambient storage conditions. The cost of storage would reduce with increase in size of the structure, and the costs of storing potato for 100 days in 1 m3 EC structures (400 kg capacity) made with pad walls and brick walls were Rs.1.22 and Rs. 2.38, respectively. The cost of storage in a 25 m3 EC structure (8 MT capacity) fitted with artificial ventilation system has also been analyzed, which is Rs. 0.81 for a storage period of 100 days. The break-even costs for potato stored under EC conditions were Rs. 3.58 and Rs. 3. 12 for wood wool pad EC storage structures of 1 m3 and 25 m3 capacity, respectively. Therefore, the EC structures could be adopted in places where cold storage facilities are not available or the transportation cost to the cold storages is very high to of fset the advantages of keeping produce in cold storages. Utilising such EC storage structures for other operations like mushroom cultivation, curing of horticultural produces, etc. and extending the number of days of operation per year would reduce the unit cost of storage and of fer a better economic picture of the EC storage structures.
