Cold storage

BEFORErefrigerators became the norm of the day, earthen pots were used to store cool drinking water. The water in the pot reaches the outer surface through the pores in the earthen pots which on evaporation, humidifies, cooling the air around it. This in turn cools the water in the pot.

Based on this principle, several low cost refrigerator models are available, which can be used for short-term preservation of household products (Changing Villages, Vol 14, No 2). Requiring a capital investment of Rs 50 only, these refrigerators are made from locally available material like clay, bamboo, sand, cloth, moistened bricks and thick ropes. Negligible maintenance and nil operational costs are its other features. The refrigerator allows household products like milk to stay put for about 20 hours, curds for five days, eggs for 20 days and vegetables for a week.

Five models of these evaporative coolers, portable and easy to assemble, are currently available in certain parts of Bihar and West Bengal. Among them is the pot in a pot system which makes the 'Earthefi Cooling Pot' refrigerator. Water is poured:mto the outer chamber and the smaller pot is used to store the food.

These rural refrigerators record temperatures four to five degrees less than the room temperature and 23-25 per cent higher relative humidity.

Apart from being ejonomically viable and environment- friendly, these refrigerators can help improve the nutritional status of the rural populace.