Eco-Buildings ‘Sweat' Out Rain Water To Cool Down In The Heat
Researchers from ETH Zurich have developed a synthetic mat that extracts heat from rooftops and releases water at its surface.
Researchers from ETH Zurich have developed a special polymer mat, which could be used to cover rooftops, as part of a new cooling system. The mat soaks up rainwater like a sponge and then when hit by the sun's rays, it releases the water at its surface and extracts heat from the building by “sweating.”
The mats use a special polymer, abbreviated to PNIPAM, which is protected by a water-permeable membrane. If the material becomes warmer than 32 degrees it shrinks up and adopts hydrophobic properties, forcing the water through the membrane to the surface of the mat, where it evaporates.