In a matter of years, residential and commercial roofs may be coated in the whitest paint ever to reduce or possibly eliminate the need for air conditioning.
The paint, developed by researchers at Purdue University in Indiana, was certified by the Guinness World Records as the whitest paint in April. The paint reflects 98.1% of solar radiation at the same time as emitting infrared heat. This is an improvement on Purdue’s previous iteration that was 95.5% reflective.
Xiulin Ruan, a professor of mechanical engineering at Purdue, invented the paint with graduate students as a way to combat global warming.
“When we started this project about seven years ago, we had saving energy and fighting climate change in mind,” said Ruan in a podcast episode of “This Is Purdue.”
Unlike typical commercial white paint, which can only reflect 80%-90% of sunlight, Purdue’s paint can make surfaces cooler than their surroundings. When it’s available, Ruan said roofing contractors and building owners can use it to help reduce energy bills. According to Purdue’s findings, using this new paint formulation to cover a roof area of roughly 1,000 square feet could result in a cooling power of 10 kilowatts.
“That’s more powerful than the air conditioners used by most houses,” Ruan said.
The researchers have partnered with a company to scale up the paint and put it on the market. Ruan said they expect it to be available to the general public in a couple of years.
"Yes, the paint is intended to be used on roofs, including roofing shingles and metal roofs," Ruan told USA TODAY. "It can be used on other infrastructures where commercial paints are used."
The paint is the result of research dating back to the 1970s. Ruan’s lab considered more than 100 different materials, narrowed them down to 10 and tested about 50 different formulations for each material.
According to Purdue, two different features make the paint ultra-white. The first is a high concentration of barium sulfate, a compound used in photo paper and cosmetics. The second is different particle sizes of barium sulfate in the paint, which allows it to scatter more of the light spectrum from the sun.
It remains to be seen whether this paint will indeed be adopted by roofing contractors. Roofing experts have previously noted that white isn’t always right and that a roof system’s success is based on all of its components working together.
