Zero Energy Cool Chamber

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An Indian institute has developed technology for zero energy cool chamber an alternative of common refrigerator. This is an on-farm storage chamber, for fresh fruits, vegetables and flowers to extend their marketability. Storage of fresh horticultural produce after harvest is one of the most pressing problems of a tropical country like India. Due to their high moisture content fruits and vegetables have very short life and are liable to spoil. Moreover, they are living entities and carry out transpiration, respiration and ripening even after harvest. The spoilage of fruits and vegetables can be controlled by reducing the storage temperature. Refrigerated cool storage is not only energy intensive and expensive, but also involves large initial capital investment.

The zero energy cool chamber can be constructed easily with materials like brick, sand, bamboo, khashkhas/straw, gunny bag etc. The chamber can keep the temperature 10-15OC cooler than the outside temperature and maintain about 90% relative humidity. Multilocational studies at different agroclimatic zones have been found it to be very useful. It is most effective during the dry season.


  • 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 wall with this wet sand
  • Make a frame of top cover with bamboo (165 cm x 115 cm) frame and sirki, straw or dry grass etc.
  • Make attach/ shed over the chamber in order to project it from direct sun or rain. Operation
  • Keep the sand, bricks and top cover of the chamber wet with water.
  • Water twice daily in order to achieve desired temperature and relative humidity or fix a drip system with plastic pipes and micro tubes connected to an overhead water source.
  • Store the fruits and vegetables in this chamber by keeping in perforated plastic crates
  • Cover these crates with a thin polyethylene sheet
  • The cool chamber should be reinstalled once in 3 years with new bricks utilizing the old bricks for other purposes.


  • Try to site in a place where breezes blow
  • Build in an elevated place to avoid water logging
  • Use clean, unbroken bricks with good porosity
  • Sand should be clean and free of organic matters, clay etc.
  • Keep the bricks and sand saturated with water
  • Roof over to prevent direct exposure to sun
  • Use plastic crates for storage; avoid bamboo baskets, wooden/fiber board/boxes, gunny bags etc.
  • Prevent water drops coming in contact with stored material
  • Keep the chamber clean and disinfect the chamber periodically with permitted insecticide/ fungicide/ chemical, to protect from fungus, insect/ pests, reptiles etc.

Areas of Application

  • Short term storage of fresh vegetables, fruits and flowers
  • Growing of white button mushroom
  • Ripening of tomato and banana
  • Plant propagation
  • Storage of processed fruit products


  • Avoid distress sale of fresh fruits, vegetables and flowers.
  • Better marketability of fresh horticultural produce than ambient
  • Retain nutritive value
  • Environment friendly storage system with no pollution

Production Capacity

100 q/chamber with the scope of scaling up to the tune of 6-7 tonne/chamber

Stage of Development

Commercialised More than two dozens of such chambers are in operation

Inputs Required

Building: Open shed (ventilated)
Land: 100 m.sq.
Water: 25-50 ltr./day (depending on location)
Manpower: Total 2 including 1 technician, 1 unskilled

Economic Data

Total project cost: Rs. 3000/- per unit approx.
Training fee: Rs. 9000/- per trainee (excluding travelling allowance)
Operational cost: Approx. Rs. 20,000 - 30,000 per year
Pay-back period: One year

Transfer Forms

Consultancy, Training

Main Application


For further information please contact

Technology Bureau for Small Enterprises
APCTT Building, Qutub Institutional Area
P.O. Box – 4575
New Delhi – 110016, India