Scientists at Purdue have created a white paint that, when applied, can reduce the surface temperature on a roof and cool the building beneath it.
Xiulin Ruan, a professor of mechanical engineering, created white paint that reflects 98% of the sun’s rays away from the Earth’s surface. When applied to the roof of structures, the paint cools down surfaces as much as eight degrees during the day and up to 19 degrees cooler at night, according to a report in The New York Times.
“If you were to use this paint to cover a roof area of about 1,000 square feet [93 m2], we estimate that you could get a cooling power up to 10 kilowatts. That’s more powerful than the air conditioners used by most houses,” Ruan said.
Scientists consider paints like this transformational for cooling down the planet and reducing electricity use, as buildings with this kind of white paint would require less air conditioning.
And Ruan doesn’t want to stop at buildings. Last year, he announced that he has invented a version of this paint for vehicles, too.
World record holder
How white is the paint? In 2021, the Guinness Book of World Records named it the whitest paint on earth. But Ruan Ruan told the Times that wasn’t the goal.
“We weren’t really trying to develop the world’s whitest paint,” Dr. Ruan said. “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.”
Unfortunately, the paint won’t be on sale for about another year, as researchers are working on improving its durability and resistance to dirt.
But with the planet recording record temperatures almost daily, the need for a global paint job couldn’t come fast enough.
Dr. Ruan, left, and Joseph Peoples of Purdue University used an infrared camera to compare the cooling performance of white paint samples on a roof.Credit…Jared Pike/Purdue University