Evaporative Cooling for Vegetable Preservation

Two examples of an evaporative cooling device for vegetable storage and preservation. Left: clay pot cooler. Right a forced-air evaporative cooling chamber.
Two examples of an evaporative cooling device for vegetable storage and preservation. Left: clay pot cooler. Right a forced-air evaporative cooling chamber.

Evaporative cooling devices have promise for helping small-scale farmers, market vendors, and families to store and preserve vegetables.

 

Practical and affordable storage technologies have the potential to prevent food loss, strengthen the perishable food supply chain, and create opportunities for additional income generation. Evaporative cooling devices 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. The improved storage environment can have positive impacts including reduced post-harvest losses, less time spent traveling to the market, monetary savings, and improved nutrition.

D-Lab's approach and work

D-Lab has identified the following five key areas where increased efforts can increase the effective production, dissemination, and usage of evaporative cooling technologies: performance and design research, suitability scoping, developing scalable dissemination strategies, user behavior and impact research, and developing a community of practice.

Our current projects include:


Resources and Reports

Provides an analysis of data from 264 interviews conducted with clay pot cooler training participants in Mali. The report discusses the storage challenges facing the training participants, the adoption of clay pot coolers after attending a training, the benefits realized by clay pot cooler users, pathways for sharing information beyond the training, and feedback the participants provided on the training program.
 
Clay Pot Coolers: Preserving Fruits and Vegetables in Mali: Report 2016-2021
Summarizes the activities of the clay pot cooler project in Mali between 2016 and 2021. This ongoing project, in collaboration with the World Vegetable Center and Institut d’Economie Rurale (IER), has consisted of multiple phases, each focusing on a different technical and social aspect of this technology.
 
An illustrated guide covering the fundamentals of how evaporative cooling works, the importance of proper fruit and vegetable storage, and best practices for assembling and using clay pot coolers. The guide is available in French and English and can be printed to form a booklet.  
 

Contact

Eric Verploegen, MIT D-Lab Research Engineer