Drinking water is a scarce resource in many parts of the world. Taking this problem into note, researchers at the Swiss Federal Institute of technology have developed a water condenser that can produce drinking water without energy input. Talk about a man-made miracle!
The condenser can be used 24 hours a day and collects water from ambient air. It relies on a self-cooling surface to passively extract drinking water.
A modern-day miracle, this device is set to help millions gain access to clean water. Although water purification technologies continuously evolved over the years, it is the first time one has been developed with net-zero energy.
So, how does this device work? And what technology is used to enable it to collect 24×7?
Let us take a closer look at the work of researchers at ETH Zurich and their priceless invention.
The Magical Water Condenser
The new device can produce almost twice as much as much water as current passive technologies available.
A specially coated glass pane both reflects solar radiation and also radiates away its own heat through the atmosphere to outer space, allowing the device to function 24 hours a day.
The coating is made of specially designed polymer and silver layers and helps the pane emit infrared radiation. The radiation is emitted at a specific wavelength and is neither absorbed by the atmosphere nor reflected back onto the pane.
The device was tested on the roof of an ETH building and appears promising. It can produce twice as much water as current foil-based passive technologies.
The small pilot system with a pane diameter of 10 centimeters delivered 4.6 milliliters of water per day under real-world conditions.
The scientists demonstrated that under ideal conditions, they could harvest up to 0.53 deciliters (approximately 1.8 fluid ounces) of water per square meter of pane surface per hour. “This is close to the theoretical maximum value of 0.6 deciliters (2.03 ounces) per hour, which is physically impossible to exceed,” says Iwan Hächler, a doctoral student in the group of Dimos Poulikakos, Professor of Thermodynamics at ETH Zurich. Larger devices with larger panes will produce greater amounts of water.
Other foil-based technologies require energy to collect condensed water. Once water condensation happens, it must be collected from the surface which requires power. However, this device lets condensed water bead up or jump off on its own. To achieve this effect, the researchers applied a water-repellant coating to the underside of the water condenser.
“In contrast to other technologies, ours can really function without any additional energy, which is a key advantage,” said Hächler, highlighting the USP of the device.
The Way Forward
The ETH researchers also pointed out the fact that it is relatively simple to produce the specially coated panes and can be mass-produced to help communities build water condensers.
According to the UNICEF, almost two-thirds of the world’s population experience sever water scarcity at least one month every year. Experts estimate that water scarcity will displace around 700 million by 2030. While improving the efficiency of water resources is the first step, it is also important to find better ways to collect water and at lower costs.
It is common knowledge that climate change has exacerbated the water crisis across the globe.
A technology that does not use energy can be highly effective in rural and remote areas, where people barely have money to spare and are more prone to malnutrition and diseases.
Scientists are looking forward to combining the water condenser’s technology with other available technologies like water desalination to reap greater benefits. Renewable technology-based products would be best suited to serve far-flung areas that do not always have the right resources.
As the world grapples with climate change and its effects, this water collection device will be a godsend in areas that are hard to reach. It can also be used in drought-prone areas as well as by first-responders while conducting search-and-rescue in disaster-hit areas.
