Air conditioning, that is, cooling the air, requires more energy than heating it. Plus, this requires special technical devices, and our globe today is already feeling the burden of global warming. It's no wonder scientists around the world are looking for simple solutions to cool our habitat, and researchers at Columbia University (USA) have a great option.
They have developed a polymer that can reflect and dissipate the maximum amount of solar energy that cannot be achieved even with traditional white paint. It's all about microbubbles - in addition to the polymer itself (it is conditionally transparent), the coating contains a solvent and water. The solvent is the first to dry after application to the wall, causing water to condense and form tiny bubbles throughout the thickness of the layer. But the water also soon evaporates and leaves voids, which serve as an anti-trap for sunlight.
Sunlight is complex in structure, but due to the difference in refractive indices between the polymer and the voids in it, radiation is reflected over almost the entire spectrum of waves. In practice, the reflection level reaches 96%, which is why the warm light of a star named the Sun has practically no effect on objects with this coating. Of course, they will still heat up from contact with air and other warm structures, but they will be colder than the surrounding objects. As much as 6 degrees in the dry desert climate of Arizona and 3 degrees cooler in the tropics of Bangladesh, without any energy expenditure.