Water from the air.
We see it on cold glasses in the summer. We feel it when a heavy fog covers the landscape. Yet, the concept of drinking water from the air has appeared to be more of a pipe-dream than a scalable reality.
High energy costs, the noise of fans required to process sufficient water, and concerns as to what other particulates and bacteria may be collected in large-scale and visibly clunky systems have prevented widespread adoption. Increasing water shortages, and concerns about contamination in existing water sources, has prompted further exploration and technology innovation to tap the water above us.
Analysis by the U.S. Geological Survey demonstrates there is more water in the air than in all the rivers in the world: 3,000 cubic miles of water, or six times that flowing in our rivers today.1 Further, Atmoswater Research, publisher of the Water-From-Air Quick Guide, noted that the volume of water in the atmosphere is so large that all 7 billion people on the planet could each use 50 liters a day and consume just 0.002% of atmospheric water.2
Water from air technology, commonly referred to as “Atmospheric Water Generation,” AWG for short, has been geographically limited to the tropics, where relative humidity is high enough for water to be consistently condensed in much the same way it is captured through a dehumidifier or air-conditioner. More than 40 case studies on the Atmoswater Research site3 detail applications around the globe, augmenting supplies when regions faced contaminants, lacked infrastructure or simply wanted extra pure water to brew beer.
Chilled-coil AWG systems use a filter when capturing water and air where relative humidity exceeds 50%
PURE WATER NEAR THE POINT OF USE
A significant advantage of tapping water from the atmosphere is that it can provide pure water at the point of use, bypassing the supply and infrastructure issues facing our cities. The need for drinking water continues during service interruptions and emergencies, so water from air solutions provide resilience to citizens and cities weathering extreme weather events and emerging contaminants.
The diagram above may help product purchasers understand how chilled-coil systems process water and ensure the quality of the water delivered through such systems.
BEYOND CHILLED-COIL SYSTEMS
An innovation by researchers at the University of California Berkeley has changed the atmospheric water generation paradigm by enabling pure water to be captured from the air inside a building and even in the desert – at an energy cost of 0.5 to 0.8 kWh/liter.
Dr. Omar M. Yaghi, professor of chemistry and co-director of the Kavli Energy NanoSciences Institute at UC Berkeley, has been focused on the atmospheric water opportunity for more than two decades. Yaghi is renowned for having pioneered reticular chemistry, a new field of chemistry that is concerned with stitching molecular building blocks together to make Metal-Organic Frameworks (MOFs).
Using a specific formulation of MOF, Yaghi has demonstrated the ability to generate water from air even in the driest conditions, as evidenced by tests conducted in the Mojave Desert.4 The characteristics of MOF technology enables rapid adsorption and desorption cycles while minimizing energy use, adsorbing only water molecules from the air.
Water Harvesting Inc., was incorporated in 2018 to take the MOF-based water-from-air technology to market. The company negotiated an exclusive commercial rights agreement with UC Berkeley. Water Harvesting Inc. plans to address the demand for potable water through distributed water systems ranging in size from 5 to 20,000 liters in production per day.
Metal Organic Framework (MOF)-based systems naturally filter water where relative humidity exceeds 7%
A NEW STANDARD
Providers of condensate systems have typically used filters and an anti-microbial treatment to address water quality, using certified labs to confirm produced water meets EPA and WHO standards. MOF- and other desiccant-based systems act as a natural filter.
ASSE and IAPMO clients can anticipate assistance in evaluating both of these atmospheric water technologies in the coming year, as ASSE 1090 is being drafted as a proposed ANSI consensus standard for atmospheric water generation. Members of the ASSE 1090 Working Group, chaired by ASSE Executive Director Tom Palkon, included 36-year water-from-air expert, Roland Wahlgren, owner of Atmoswater Research, and water quality veteran, Frank Brigano, Vice President of Marmon Water, a division of Berkshire Hathaway.
“Standards legitimize an industry and should also make it easier to assess solution providers,” says Brigano. “The beauty of AWG systems is that they are disconnected from municipal systems and their inherent ‘issues.’ Thus, making claims of ‘free from heavy metals and organics, worry-free from boil water warnings, PFAS, etc.,’ are what makes these systems attractive.”
Water industry investor and serial entrepreneur Mike Reardon, former chief executive of Culligan Water, is also enthusiastic about the prospects for this new technology. He believes it presents an “exciting new frontier that could dramatically change the approach to solving the world’s water problems with, in effect, a fresh “source” of water.”
He compared the potential of renewable clean water from air, to the promise of unlimited, renewable electricity from solar cells.
“While the rest of the world works with conventional technologies on treatment and conveyance of the existing water supply to where it is most needed, atmospheric water offers a virtually unlimited new resource through the conversion of air into good clean water.” And this water is available everywhere all around us!
- U.S. Geological Survey: “Where is Earth’s Water.” https://www.usgs.gov/special-topic/water-science-school/science/where-earths-water?qt-science_center_objects=0#qt-science_center_objects
- Wahlgren, R., “Water-From-Air Quick Guide”, CreateSpace Independent Publishing Platform; 2nd edition, 2016.
- Atmoswater Research, Case Studies About Water-from-Air, https://www.atmoswater.com/case-studies-about-water-from-air.html
- University of California Berkeley: “Water Harvesting Makes It Easy to Drink Water From Thin Air,” https://www.universityofcalifornia.edu/news/water-harvester-makes-it-easy-drink-water-thin-air
Article by Mary Conley Eggert and Frank Slovenec first appeared in ASSE’s Working Pressure magazine