Most of us do not realize that there is a shortage of fresh drinking water in many countries. It is a scarce natural resource that is under threat from humanity’s ever-increasing demand, along with atmospheric changes and global warming.
But what if you could make water from air?
There are an estimated 13 trillion liters of water floating in the atmosphere at any one time, equivalent to 10% of all of the freshwater in our planet’s lakes and rivers. According to the U.S. Department of Energy, when it’s hot and humid, evaporated water can make up as much as 6 percent of the air we breathe. This air is part of the water cycle.
Water evaporates out of rivers, lakes, and oceans. It’s carried up into the atmosphere, where it collects into clouds (which are actually just accumulations of water vapor). After the clouds reach the saturation point, water droplets form, which we know as rain. This rain runs off the land and collects into bodies of water, where the whole process begins again.
Instead of waiting for rain to replenish the water source, some inventors and companies are working to pull the water vapor out of the air daily.
Water from Air™ machines work with relative humidity and the temperature in our atmosphere. Relative humidity and the temperature combined produce an absolute humidity in g/kg. The water vapor passes through an air filter and hits the condensing coils within the machine. These sophisticated coils allow the water to cool down sufficiently to reach dew point. This converts the water vapor into a liquid state.
Pulling water from the air seems impossible in desert areas, but scientists are working on that as well. According to the MIT Technology Review, scientists have developed a device that can suck water out of desert skies powered by sunlight alone. They hope that a version of the technology could eventually supply clean drinking water in some of the driest and poorest parts of the globe.
The device is based on a novel material (MOFs) that can pull large amounts of water into its many pores. According to a study published in the journal Science, a kilogram of the material can capture several liters of water each day in humidity levels as low as 20 percent, typical of arid regions. This means it could provide water for parts of the world likely to be most vulnerable to water shortages under future climate change, including areas afflicted by recurring drought.
On an individual level, an Australian inventor has created a machine that uses wind power to collect water out of the atmosphere. Max Whisson is the creator of the Whisson Windmill, which uses refrigerant to cool the blades of his mill. These blades are situated vertically rather than diagonally, so that even the slightest breeze turns them. The cool blades cool the air, causing the water vapor to condense — become liquid water again. This condensation is then collected and stored.
The profession of pulling water out of air is becoming the next new discovery. Google ”air to water” and you will find a dozen corporations working on the same idea. Companies and other sources are devoted to finding a way to get water to those who need it, including water from the air. It is a discovery well worth working on.
Curious about how the water cycle works? Nasco has a number of kits that explain the water cycle, water treatment and filtration, and the principles of groundwater. Check these out with your students and see what you can find.