Have you ever noticed that sometimes – particularly in summertime – it’s actually harder to be inside a building than outside? I remember one office building that I worked in, the sun would always hit right in the hottest part of the afternoon, and my cubicle would quickly start to heat up, despite the walls being stark white.
By the time I left, I’d always notice it was a bit cooler outside than inside. However, there is some interesting news coming out of Purdue University where researchers have claimed to have developed a paint so white that it could reduce – potentially phase out – the need for air conditioning.
A mechanical engineer with Purdue, Xiulin Ruan, has invented the special paint with the collaboration of his grad students. They wanted to create a paint that would reflect the sun enough to save energy and help to fight global climate change.
They created a formula that reflects 98.1% of solar radiation while also beaming infrared heat. Apparently, the paint will absorb less heat from the sun than it puts out, and will not consume power in order to keep the surrounding temperature cool.
White paint will typically get warmer instead of cooler when it’s exposed to the sun – even when there are paints that are designed to reflect 80-90% of sunlight. But according to the researchers at the university, 1,000 square feet coated in their white paint formula can actually be the same as 10 kilowatts of cooling power – something that Ruan states is more powerful than most air conditioners in homes.
Ruan and his team went through more than 100 different materials before narrowing them down to 10 and then testing out 50 different formulas on each material. Ruan and his team make the super white paint by using a high concentration of a chemical compound known as barium sulfate.
Purdue explained, “What wavelength of sunlight each particle scatters depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.”
While the university has said that there is still room for improvement of the paint to get it whiter, it wasn’t entirely possible without compromising the paint. Still, the paint is quite white and has even earned the Guinness World Records title “whitest paint” and will be featured in their “Guinness World Records 2022” book.
The patent applications have already been filed, the next step is to get the paint to market using a partnership with a company.