M A I N   N E W S

DRDO comes up with zero-energy cooling chambers for deserts
Vijay Mohan
Tribune News Service

Chandigarh, November 4
Amidst rising environmental concerns and increasing power costs, the Defence Research and Development Organisation (DRDO) is bringing to the fore an ancient “zero energy” cooling technique that is dependent on the natural evaporation of water.

This is something similar to earthen pots widely used to chill water. Transfer of heat due to evaporation of water from the surface of the cooling vessel ultimately leads to cooling the atmosphere within the vessel.

Several types of zero-energy cooling chambers have been developed by the DRDO, which include large brick-walled fixed coolers as well as portable and mobile metal and plastic chambers. User trials of metallic and plastic containers have been carried out at an Army Service Corps depot in Jodhpur and based on the feedback, these have been recommended for induction into military units located in forward or desert sectors, the latest issue of DRDO’s in-house technical bulletin has reported.

The technique can be used for storing perishables like fruits, vegetables, mushrooms, milk and eggs for extended periods of time. The containers and chambers can store 50-150 kg fresh produce and under ideal temperature and humidity conditions, the temperature gradient inside the chambers can be maintained between 6-9° Celsius.

According to the bulletin, a number of zero-energy cooling systems have been reported in India earlier and several double-walled brick chambers with and without ventilation have been made. However, cross ventilation in these containers to minimise use of water and the construction material needed further improvements.

Besides the military, these chambers can also be used by farmers, commercial kitchens, commercial centres as well as households in areas facing an energy crunch. Measures like controlled dripping of water and use of material conducive for capillary action and lower thermal conductivity can enhance their effectiveness.

Looking AHEAD

Several types of zero-energy cooling chambers have been developed by the DRDO, which include large brick-walled fixed coolers as well as portable and mobile metal and plastic chambers. User trials of metallic and plastic containers have been carried out at an Army Service Corps depot in Jodhpur and based on the feedback, these have been recommended for induction into military units located in forward or desert sectors.