Forced-Air Evaporative Cooling Chambers
Off-grid pre-cooling of fruits and vegetables
Forced-air evaporative cooling is well suited to provide rapid pre-cooling and improved storage of fruits and vegetables.
Chambers with this design typically cost less than half the cost of a refrigerated cold room.​
Features of a forced-air evaporative cooling chamber
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Provides the greatest value in hot and dry climates
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Ideal for fruits and vegetables that store well in high humidity environments
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Forced airflow is ideal for rapid pre-cooling
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Lower energy consumption and half the cost of refrigerated cold rooms
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Can be powered by off-grid solar energy systems
Extending vegetable shelf-life
​The images to the left are from an experiment with a forced-air evaporative cooling chamber in Kibwezi, Kenya.
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The shelf life of spinach is extended from 2 days to over 5 days when stored in the chamber, compared to storage in a basket placed in the shade outside of the chamber. ​
The CoolVeg team has designed, tested, and deployed several types of forced-air evaporative cooling chambers
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Shipping container based cooling chamber:
​ Large storage capacity
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Portable cooling chamber:
​ Least expensive and easiest to make.
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Mobile cooling chamber:
​ For use in transportation applications.​
Shipping container based forced-air evaporative cooling chamber
Storage capacity of 168 crates
Led by CoolVeg founder Eric Verploegen, a team at MIT designed a forced-air evaporative cooling chamber that can be built in a used shipping container. Detailed documentation of this open-source design can be found below.
Pilot chambers were built and tested in partnership with Hunnarshala Foundation in Bhuj, India and Solar Freeze in Kibwezi, Kenya.
Portable forced-air evaporative cooling chamber
Storage capacity of 15 to 30 crates
CoolVeg developed the modular forced-air cooling chamber concept with support from Efficiency for Access' R&D Fund. This design is easy to construct, can be tailored to meet users' capacity requirements, and can be carried by 6 people or transported on a small truck. Testing of these chambers is underway in India and Nigeria.
Mobile forced-air evaporative cooling chamber
Storage capacity of 32 to 64 crates
CoolVeg developed the mobile forced-air cooling chamber in partnership with Cold Hubs in Kaduna, Nigeria, and support from Efficiency for Access' R&D Fund. This chamber is designed to allow fruits and vegetables to be picked up at farm gates and pre-cooled while in transit on rural roads to markets.
Video: Cooling Chamber in Kenya
Components of the Airflow System
The diagram below is a head-on cross-sectional schematic of a shipping container based forced-air evaporative cooling chamber. The key components of the chamber's airflow system are labeled.
