The world’s whitest paint could slash the need for ACs by 40%

Ultra white paint, a cool solution to a warming planet: An ultra white paint developed by a team of engineers at Purdue University could reduce the need for air conditioning in buildings as the world continues to warm, The New York Times reported last week. The paint, which is a Guiness World Record holder as the world’s whitest paint, now has the world waiting. “We weren’t really trying to develop the world’s whitest paint,” said Xiulin Ruan, a professor of mechanical engineering at Purdue University. “We wanted to help with climate change, and now it’s more of a crisis, and getting worse. We wanted to see if it was possible to help save energy while cooling down the Earth.”

How it works: The paint — first unveiled in 2020 — can reflect 95% of the sun’s rays away from Earth and into space. Since that announcement, the team has developed a formula that raised sunlight reflection to 98%. The paint can make surfaces up to 8°F cooler than air temperatures at midday and up to 19°F cooler at night. This would help reduce temperatures inside buildings and slash the use of ACs by nearly 40%.

Don’t expect it to roll out soon: The paint won’t be ready for commercial use for at least a year, Ruan said. His team is also working on developing colored paints that use the ultrawhite as a base. “They will work less ideally than the white, but better than some of the other commercial colors,” he said.

Not fully-climate friendly: The standard version of the ultra white paint uses barium sulfate, which needs to be mined in a process that produces carbon emissions. However, Ruan says it creates no more damage than producing regular commercial paints, which use titanium dioxide that also has to be mined.