From Zeer Pot to Evaptainer, from the Middle East to Arizona, how sunlight and water can address food spoilage when electricity isn’t an option

By NOUR HAKI

Arizona Sonora News Service

Everybody in southern Arizona knows what an evaporative cooler is. This technology, which pre-dated the wide residential availability of air conditioning, largely enabled a great population influx to the hotter, drier regions of the American Southwest in the 1940s through the 1960s.

Now the same evaporation technique — an ancient low-tech air conditioning technology that was perfected in the Middle East during the Middle Ages — is being modified for widespread use as a way to help preserve stored food better in developing countries.

“In the older days, everybody had a swamp cooler particularly in Arizona, because the cooling system works very well with our weather,” said Alfenso De La Riva, the general manager of Perry Heating and Cooling Company in Tucson. “Mexico embraced this technology by using it considerably before the birth of Arizona.”

 

Illustration by Mikayla Mace / Arizona Sonora News Service
Illustration by Mikayla Mace / Arizona Sonora News Service

This technique goes back thousands of years ago when the windcatcher was used as a form of air-cooling in ancient Egypt and Persia. Windcatchers, popular in ancient Persian architecture, are shafts on the roof that catch the wind, passes it over subterranean water in a channel then diffuses the cooled air into the building. “Iranians and Indians have changed the windcatcher into an evaporative cooler by using wood wool pads, as an element to bring water, in contact with air inside a metal box.” said Robert Williamson, the owner of the Williamson’s Heating and Cooling company in Tucson.

This is the origin of evaporative cooling systems, which are also known as swamp coolers in the Sonoran Desert.

Now new innovations in evaporative cooling principles are being developed to address one of the basic problems in developing countries, the need to keep stored food cool in hot, dry climates without depending on electrical refrigeration, including in parts of Africa and the Middle East. One such technology is called the Evaptainer.

Evaptainers are  based on a design by Quang Truong, a graduate student at the Fletcher School of Law at Massachusetts Institute of Technology. Through his travels around the world, he pondered the issue and developed the idea and initial design at an MIT class to reduce the spoilage of fresh produce. He says he came up with the idea of Evaptainers based on a rudimentary idea of evaporative coolers or “Zeer pots” being used in Nigeria and other developing countries.

“In each country he worked in for an agricultural development, he witnessed large-scale food spoilage,” said Serena Taylor, the director of strategic planning Evaptainer company in Somerville, Massachusetts.  About 470 million small-scale farms in developing countries, such as Haiti and Vietnam, lose an average of 15 percent of their income to food spoilage. In Africa, 45 percent of the food grown is lost to post-harvest food spoilage.

This functioning device is similar to a refrigerator, but runs only on sunlight and water. Just like swamp coolers, the Evaptainers use the basic principle of evaporative cooling. Drawing energy from its surroundings, evaporating water produces a considerable cooling effect. The cooler air pushes the heat out of the interior onto conductive aluminum plates that are attached to a special fabric to maintain wetness, and the heat naturally blows through evaporative cooling.

Truong, along with co-founder Spencer Taylor, teamed up to create their own company in Somerville. The product is in a late stage of development for commercial release. Evaptainers are most efficient in areas where the average relative humidity falls below 40 percent. These areas include much of North Africa and the Middle East, parts of the rest of Africa, South Asia, South and Central America, and the southwestern deserts of the United States.

“Quang wanted to update the design using modern materials so that they could be transportable, durable, and easy to use,” Serena Taylor said.

Water is a necessity. To keep food cold, Evaptainers require six liters of water every 12 hours. The unit can hold up to 60 liters of produce.

The Evaptainers tend to increase in food security that can lead to higher rates of nutrition, education, and better health outcomes. “As people begin saving money as a result of their food not spoiling and their not having to travel to market as frequently, their household incomes will increase,” Taylor said.

“It is our hope that our product can help to reduce this number and thereby alleviate food insecurity and the greenhouse gas emissions caused by spoiled food.”

“The government is always looking at ‘Going Green’,” De La Riva said.

The government aims to regulate the swamp coolers by bringing modern systems to save more water in the hot regions and push towards the high efficiency unit by giving people tax credits.

The Evaptainer Company anticipates that their technology will become a viable refrigeration solution in areas with little to no reliable electricity, and in areas where average household incomes are low enough that a traditional compression refrigerator is not an affordable expense.

Otherwise, the company believes there is a commercial market for this modifications in technology in areas with reliable electricity — for backpackers, hunters and people who love camping. “Anyone who is in the backcountry without access to electricity who is looking to keep food from spoiling could find an Evaptainer useful,” Taylor said.

The cost of the Evaptainers per unit will be approximately $25. But the company is still investigating different business models that would subsidize purchase of the units.

Although the Evaptainer is currently being tested in Morocco, the company expects to expand their range to the Middle East, North Africa, India and Nigeria. “We are currently in the process of rolling out a 300-unit field trial and the units are not yet available for purchase.”

The company is also looking into the possibility that Indian tribes in the Southwest, including Arizona, could use Evaptainers.

“Surprisingly, the rural electrification rates on tribal lands is quite low and we have heard that our product may be useful there,” Taylor said.

 

Download high resolution images here.

nourBorn in Iraq, raised in America, Nour Haki is a journalism major at the University of Arizona. Curiosity is what drove her to journalism, and she hopes to land a career in the fashion journalism field. Why fashion? She has always been passionate about the creative aspects of it and the way it applies to herself personally, art and society.

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