A team of engineers at Purdue University has created the whitest paint in history and says that using it on buildings may help cool them down, reducing the need for air conditioning.
The research team created an ultra-white paint last year, but have since improved the formula.
Purdue professor of mechanical engineering, Xiulin Ruan, told Science Daily that if the paint were used to cover a 1,000 square foot area of roof (93m2), it could provide cooling power of 10kW.
“That’s more powerful than the central air conditioners used by most houses,” he says.
The paint sends infrared heat away from a surface and can reflect up to 98.1 per cent of sunlight. It contains a high concentration of a chemical compound called barium sulfate, which creates a highly reflective surface.
The barium sulfate particles in the paint are different sizes, allowing the paint to scatter more of the light spectrum from the sun.
Purdue PhD student in mechanical engineering Joseph Peoples says a high concentration of different-sized particles gives the paint the broadest spectral scattering, which contributes to the highest reflectance.
A typical commercial paint that is designed to reflect heat only reflects 80–90 per cent of sunlight.
The paint is the result of six years of research. The research team used temperature-reading equipment called thermocouples to demonstrate the paint can keep surfaces cooler by up to 10.5°C at night, and by 4.5°C during the day.
The Purdue Research Foundation Office of Technology Commercialization has filed a patent application for the paint. For more information, please click here.
Image shows Xiulin Ruan holding the whitest paint. Image credit: Xiulin Ruan/Purdue University