Throughout the world, people live in climates or harsh and arid areas where there is very little drinking water and available. The researchers from ETH Zürich developed a condenser to be used in countries where water is shortly supply. It is the first zero energy solution that harvest water directly from the atmosphere throughout the daily 24-hour cycle.
The device uses a surface of autocolence and a special radiation shield. Systems for water collection of the atmosphere generally require a high energy entry or depend on passive technologies that exploit the temperature change between day and night. Another available technology includes dew collection sheets that can only extract water at night because the sun has to heat the sheet during the day that makes condensation possible. The new technology of ETH Zürich has a specially coated glass panel that reflects solar radiation and pulled away its heat through the atmosphere.
In the lower part of that glass panel, the water vapor of the air condenses the water. Researchers say that the process used by its technology is the same process that happens in poorly isolated windows in the winter. Scientists cover the glass with a special polymer and silver layers. The special coating causes the panel to emit infrared radiation in a specifically wavelength window to the outer space without absorption by the atmosphere or reflection again on the panel.
Another key element in the design of the system is a cone-shaped radiation protector that diverts heat radiation from the atmosphere to protect the glass panel from solar radiation. The shield allows the device to radiate the heat outward itself in a completely passive way. The researchers found that the new technology can produce at least double water per day by the area as the current current passive technologies that sheets use.
The researchers created a small pilot system with a diameter of the 10-centimeter panel and was delivered to 4.6 milliliters of water per day under conditions of the real world. A greater device with larger panels would produce more water. Under ideal conditions, the device could harvest up to 0.53 water deciliters per square meter surface of the panel per hour. The theoretical maximum value for collection is 0.6 deciliters per hour, which is physically impossible to exceed. Scientists in the project Please note that multiple systems can be placed to harvest more water.