Most people are familiar with the idea that painting the roof of the building with white paint can help to cool it down by reflecting sunlight. But just how much temperature reduction is possible depends on the type of paint used. Since the 1970s, radiation cooling paint has been used to enhance this effect. However, none of the paints have fallen below ambient temperature. Probably so far, that is.
Engineers at Purdue University have developed a new formulation for white paint that is able to lower the temperature of surfaces to 18 ° F (-7 ° C) above their ambient temperature. Furthermore, it achieves this impressive refrigeration effect without energy consumption. Which can make it a valuable weapon in the fight against climate change.
"It sounds quite counterproductive but it really works," Purdue professor of mechanical engineering Shilin Rouan was quoted as saying by Tips Clear. "First of all, our paint can reflect 95.5% sunlight, which means that it is almost not warmed by sunlight. In addition, it emits radiant heat in the infrared, and this heat passes through an atmosphere that has a transparent window in the wavelength range of 8-13 μm directly into deep space, at −270 ° C. Extremely cold heat sink. [With] Together these two factors, the paint can be cooled below the surrounding temperature by a deeper space. "
Paint formulations have many variations from regular paint, such as calcium carbonate filler instead of titanium oxide, and a variety of particle sizes, which help it disperse more effectively sunlight. Ruan suggested that paint could have a wide range of potential applications. Apart from cooling buildings (which, as a result, cannot power AC), it has been used extensively in data centers, utility systems, on cars, in outdoor electrical equipment and, well, basically anywhere else. can go. You want to take a cold place.
"It not only saves energy, but [can] Also reduce CO2 emissions associated with production [this] Energy saving, "said Ruan.
He said that the team is actively exploring to bring it to market. "We are already trying to commercialize the technology by talking to major manufacturers," Ruan said. "Some of the next steps include investigating long-term durability and developing colored cooling paints."
A paper describing the work was recently published in the journal Cell Reports Physical Science.
Editors recommendations