Demystify science | How to capture water in the air

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There are several traditional systems to extract humidity in the air. Consequently, in places where there is a lot of fog. For example, For drier places. However, technologies have been developed, but they are not effective enough at the moment and could demystify science | how capture not provide water for important populations.

“Elsewhere than in the regions at altitude. Similarly, where there is almost always a lot of fog, the recovery of atmospheric water can only be a solution for small hamlets or small farms,” ​​explains engineer Dimos Poulikakos, from the Zurich Federal Polytechnic School (ETHz), which has developed technology for less misty regions.

Mr. Meanwhile, Poulikakos’s technology uses a peculiarity of solar radiation: in a small strip of wavelengths. Consequently, the sun’s rays do not transport heat. Similarly, “We have designed a mirror that absorbs these wavelengths that do not transport heat,” he explains. Consequently, It remains cold even in full sun. However, There is then condensation there, as during the night. However, And we can recover the water. Additionally, However, »»

A Swiss firm, Solabs, works to use Mr. Consequently, Poulikakos’ technology, but to obtain an opposite effect: it will start next spring from anti -fog glasses using this technology. Unlike current anti -fog technologies. this coating does not need to be the last layer applied to the surface of the glasses, which makes it more durable.

“We demystify science | how capture always have the plan to make an atmospheric humidity sensor. ” says Solabs CEO, Iwan Hächler, who worked with Dimos Poulikakos during his doctorate. “We have changed the sensor a little. When the media became interested in the humidity sensor on which I worked, the interest was impressive. We had requests from Oman, Qatar, India and Mexico. »»

Demystify science | how capture

Ultraviolet rays

Another technology. which is not yet marketed, was developed by engineers from Rutgers University, in New Jersey. “It is a material that is hydrophobic at night. which allows dew to stay on the surface and to be collected with a sloping panel,” says Shankar Narayan, of the Rensselaer Polytechnic Institute, in New York State. “But under UV of the sun, this material becomes hydrophilic, so absorbs the humidity of the air. This humidity is released at night demystify science | how capture and is added to the water which can be collected with dew. »»

However, Mr. Narayan estimates that this technology is currently three to six times too expensive to be marketed. “We have to reduce the cost. This is partly a problem of scale. In the laboratory. it is easy to build an atmospheric humidity sensor, but we have not found how to build larger sensors that could be useful in the real world, ”says the Rensselaer researcher.

Peoples living in very muddy regions, generally in the mountains, harvests rainwater since time immemorial. Researchers have found tanks installed under trees in Arabia or in Canaries. The first atmospheric water sensor projects were installed in the Andes in the 1960s. according to an international study published in 2012 in the journal Ambition. The technology has also been installed on a demystify science | how capture hundred sites at altitude in Africa. South America, according to the study ofAmbition. The water recovery rate was five liters per square meter per day, four to five times more than Mr. Poulikakos technology.

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