MIT D-Lab Publications Evaporative Cooling Best Practices

Producing and using evaporative cooling chambers and clay pot coolers

Eric Verploegen Peter Rinker Kukom Edoh Ognakossan June 2018

When affordable and effective post-harvest storage solutions are in short supply, populations will often experience vegetable spoilage, loss of income, lack of access to nutritious foods, and large amounts of time spent purchasing vegetables, particularly in rural communities. Devices such as evaporative cooling chambers (ECCs) and clay pot coolers are simple and inexpensive ways to keep vegetables fresh without the use of electricity. These devices function according to a basic principle called “evaporative cooling,” where the evaporation of water from a surface removes heat, creating a cooling effect. Evaporative cooling can improve vegetable storage shelf life by providing:

• A stable storage environment with low temperature and high humidity, which reduces the rate of respiration and water loss and spoilage in most vegetables.
• Protection from animals and insects that contaminate and eat the vegetables

The improved storage environment can have positive impacts including reduced post-harvest losses, less time spent traveling to the market, monetary savings, and increased availability of vegetables for consumption. These devices can also have farther-reaching impacts, particularly on women, who often make pottery and could benefit economically from producing clay pots with local materials, as well as selling fruits and vegetables in more flexible markets that have access to evaporative cooling technology.