The farmers and vegetable grower in Banda (Bundelkhand in Uttar Pradesh) District tried a brick cooling store to preserve a vegetable. They shared that near about a week they can protect their product in a ZECC (Zero energy cooling chamber) from spoilage. In rural and remote like Bundelkhand area, the quality deterioration of horticultural produce takes place immediately after harvest due to lack of  storage and most critical is transportation; poor connectivity from remote to urban area. Maintenance of low temperature is a great problem in an area like Bundelkhand in India. There is no electricity available, refrigeration is energy intensive and is expensive, not so easy to install and run in remote area. Due to lack of cold/cool storage space a substantial amount of fruits and vegetables are lost after production.

Considering problems and limitations, proposed ZECC can play vital role to justify the hard working women farmers by retaining freshness of the fruits and vegetables for short period to get maximum benefit without any further expensive investment.

Zero Energy Cooling Chamber
A woman farmer works with a brick cooling store

What are we talking about?           

Zero energy cooling chamber is rectangular structure constructed of locally available material for storage of an agricultural produce based on principle of direct evaporation cooling like earthen pot which is used for chilling the water to maintain low temperature and high humidity.

Evaporative Cooling

  • A gift of nature – principle depends on cooling by evaporation.
  • As water evaporates it has a considerable cooling effect and faster the rate of evaporation greater the cooling.
  • Evaporative cooling occurs when air, which is not already saturated with water, passes over a wet surface.
  • Water evaporates into air raising its humidity and same time cooling the bed.
  • Efficiency of evaporative cooler depends on humidity of the surrounding air.
  • Very dry, low humidity air can absorb a lot of moisture so considerable cooling occurs. cooling occurs.
  • In extreme case of air that is saturated no evaporation can take place and no cooling occurs.
  • In theory lowest temperature that can be reached is wet bulb temperature.

Concept of Zero energy cooling chamber (ZECC)

  • Cool chambers can reduce temperature by 10-15 degree celcius and maintain high humidity of about 95% that can increase shelf life and retain quality of horticultural produce.
  • Based on the principle of direct evaporative cooling zero energy cool chambers have been developed. The main advantages of this on-farm low cost cooling cooling technology technology are:
    1. It does not require any electricity or power to operate
    2. Materials required like bricks, sand, bamboo etc. available easily and cheaply.
  • It is a double brick-wall structure, structure, the cavity is filled with sand and walls of the chamber are soaked in water.
  • Technology Vision 2020 has identified it as a low cost storage technology for 2020.
  • National Horticulture Board is giving 100% grant in aid for the benefit of the farmer.

Easy procedure of construction

  • Select an-upland having a nearby source of water supply
  • Make floor with brick 165 cm x 115 cm.
  • Erect the double wall to a height of 67.5 cm leaving a cavity of 7.5 cm.
  • Drench the chamber with water. Soak the fine river bed sand with water.
  • Fill the 7.5 cm cavity between the double walls with this wet sand.
  • Make top cover with bamboo (165 cm x 115 cm ) frame and ‘sirki’ straw or dry grass.
  • tin like shed made over chamber to protect from direct sun or rain or snow.