Wakati keeps produce fresh with hot, humid air instead of cold, using a solar-powered tent

In a December 2014 Fast Company piece, Adele Peters writes that around 40 percent of crops in countries like India and Uganda never reach market. Without money or power for refrigeration, produce rots before slow transport can carry it to buyers. Traditional evaporative coolers have preserved food for thousands of years, but use too much water to be sustainable.

Belgium-based product designer Arne Pauwels noticed that these coolers preserve food without lowering temperatures much. He put an evaporator and some lettuce in a waste paper basket, heated the room above 86 degrees Fahrenheit and waited a couple of days. The lettuce inside looked fine, and the lettuce outside was completely wilted.

He built that into Wakati, a tent-like structure with a tarp, a frame, zippers and an evaporator, run by a small solar panel. Fast Company reported tests showing it works better than traditional evaporation coolers, saves water and is self-sterilizing. It keeps bananas or mangoes essentially as well as a fridge, and the article says it can make produce last up to 10 times longer.

Wilting is a loss of water from cells, not only a matter of temperature.

A saturated hot microclimate stops that loss without the energy of cooling.

A tent with a small solar evaporator needs no grid power.

Aiming at storage of up to 10 days is long enough to reach markets.

Test what the proven solution actually does; cooling may be incidental to the real mechanism, hydration.

The Fast Company article describes a new low-cost product and gives no sales, deployments or field results. Pauwels says it focuses on short-term storage of up to 10 days and cannot keep produce as long as an industrial fridge.