Purdue Creates Whitest Paint On Earth And It Could Eliminate Air Conditioners

September 18, 2021

A Purdue University professor of mechanical engineering and his students have created the whitest paint on record.

Credit: Purdue University / John Underwood

When Purdue University researchers set out to develop a new paint, the goal was to create one that would reflect sunlight away from a building. It turns out they also set an official Guinness world record for the whitest paint on the planet.

"When we started this project about seven years ago, we had saving energy and fighting climate change in mind," Professor Xiulin Ruan said.

The paint reflects 98.1% of solar radiation while also emitting infrared heat.

Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power.

Typical commercial white paint gets warmer rather than cooler. Paints on the market that are designed to reject heat reflect only 80%-90% of sunlight and can't make surfaces cooler than their surroundings.

Researchers did an outdoor test with an ambient temperature of 43 degrees Fahrenheit. The paint lowered the sample temperature by an additional 18 degrees.

"That's more powerful than the air conditioners used by most houses," Ruan said.

Purdue said it has already filed patent applications and researchers are working with a company to scale up the paint to put it on the market.