The growing energy consumption for cooling buildings will become one of the main problems in the near future, therefore, in this area, scientists are paying more and more attention to passive systems. Engineers from the University of Buffalo (USA) have modernized the installation of an existing cooler, which works on the principle of radiation transfer, doubling its efficiency. But they did not stop there, but figured out how to solve the problem of heating the cooler itself from sunlight.
The technology itself for cooling rooms by transferring radiation through a heat-conducting plate is not new and has two fundamental drawbacks. It absorbs heat from the room air and converts it into infrared radiation, which is directed into the atmosphere without interference. However, the plate radiates heat from both sides, so that some of it rushes back and is not actually dissipated. In addition, the main work takes place during daylight hours, when buildings are warmed by sunlight, but the cooler plate itself heats up at the same time.
To solve the problem, the engineers placed an emitter plate between two inclined mirrors in the shape of the letter "V" - they reflect radiation from both sides. The mirrors themselves are also complex, they consist of 10 thin layers of silver and silicon dioxide, which allows them to reflect medium-wavelength infrared waves, but absorb short and light in the visible spectrum. These two processes run in parallel - the heat from the building goes into space, the heat from the Sun is absorbed by the mirror.
The absorbed heat is not wasted uselessly, but is transferred to heat the liquid heat carrier - water. During the experiments, it was possible to warm it up to 60 ℃, which is very convenient for use in everyday life. In terms of cooling, the temperature inside the test setup dropped 12 during the day and 14 ℃ at night. And all this without the use of any mechanisms and energy consumption.