Air alchemy: If it must be humid, make it useful
By ASSOCIATED PRESS
Published October 2, 2006
TALLAHASSEE - In a country like the United States, one of the human body's most urgent needs is taken for granted. It comes easily out of our faucets, and gallon jugs of it cost less than a dollar.
Until something like a hurricane makes clean drinking water hard to find.
But the Southeast's climate provides something besides hurricanes in summer: humidity.
As emergency officials ponder how to better help their residents after disasters, some companies are pushing machines that pull the humidity from the air and turn it into drinking water.
A few are also touting the machines as a potential solution to the clean water shortages that plague the Third World, pushing aside concerns that the machines are inefficient and require fuel that also might be scarce.
The biggest machines can make 5,000 liters of water a day, enough to provide about a gallon to 1,250 people. Small units cost several hundred dollars, while the biggest, most elaborate cost half a million.
"Tap water systems get knocked out, bottled water often disappears even before the storm shows up ... so this becomes a way to get drinking water that you can count on no matter what," said Jonathan Wright, president of AquaMagic, one of the companies selling the machines.
The Ogden, Utah, company recently towed a portable unit around the Southeast, demonstrating it to fire departments, rescue workers and city officials. AquaMagic's unit is too small to serve a whole city, but could at least provide water for rescue and cleanup workers so they wouldn't have to cart in truckloads of water, Wright said.
One potential buyer is David Roberts, who as fire chief in Biloxi, Miss., oversaw crews working in the aftermath of Hurricane Katrina, which leveled much of his city.
"You don't realize how bad you need water until you don't have it," Roberts said. "In August, the humidity's 95 percent and it's 95 degrees. You can drink a quart of water and it goes right out of you in about 30 minutes."
He called the AquaMagic machine "a great piece of equipment."
"The water tasted good, too," he said.
Most of the companies making the machines aren't focused on the U.S. market. Some, including one based in Miami Beach and another in Hollywood, Fla., are selling machines where clean water is always hard to find: villages in the developing world.
Scientists who study water shortages say that while the technology works simply and could be part of the solution, there are cheaper and easier ways to provide large-scale water purification if cleanliness is the issue.
The simplest is boiling it to remove microbes, or treating it with chemicals like chlorine, said Dr. Mark Sobsey, a professor of environmental sciences and engineering at the University of North Carolina.
Until recently, there's been little interest in the technology because water is generally easy to get from streams or underground wells and, even in poor countries, it's cheap.
"It's been really only in the last 10 years that water scarcity has been appearing in a lot of places, mainly due to the growth of the human population ... and pollution," explained Roland Wahlgren, a physical geographer who studies water supply and is working to develop air-to-water systems with a Canadian company called Wataire Industries.
AquaMagic's envisioned niche notwithstanding, the systems still aren't generally economically feasible on a large scale in developed countries with plentiful clean water like the United States.
Air Water's machine was used after the 2004 Asian tsunami, and the military in India has recently signed on to send it into the field with troops.