A new thermal insulation coating system which can cool down buildings and make them more energy efficient has been launched by AkzoNobel in China.

Featuring a radiative cooling topcoat and a thermal radiation barrier midcoat, the innovative technology from the company's Decorative Paints business acts like a sunscreen. It means the surface temperature of buildings can be lowered by up to 10% during hot summer months compared with using conventional coatings.*

The passive radiative cooling process the system uses involves emitting heat lost through thermal radiation into outer space. It’s expected to significantly enhance energy-saving performance—particularly when renovating existing buildings—and has been successfully tested on several buildings in the Lingang section of the Shanghai Pilot Free Trade Zone.

Credit: AkzoNobel

“This is a significant breakthrough in architectural coatings and opens up new avenues for energy-efficient building renovations,” says Karen Yin, director of the company’s Decorative Paints China North Asia business and president of AkzoNobel China. “We aim to provide consumers with safer, more sustainable and comfortable living environments while contributing to China’s dual-carbon policy, which is focused on both controlling total carbon emissions and carbon emissions intensity.”

The midcoat uses advanced aerogel insulation materials, which have extremely low thermal conductivity, helping to effectively block the transmission and penetration of heat. The topcoat is an upgraded version of heat-reflective coatings, offering higher reflectivity to further reduce solar heat absorption. It also has high thermal emittance, allowing it to directly emit heat back into the atmosphere, mitigating urban heat island effects. Both of these coatings are low-VOC and fully water-based.

Adds Yin: “The science behind these ‘cool coatings’ might be complex, but the effect is easily explained. A ‘normal’ exterior coating will heat up in the sun because it still absorbs some sunlight. A heat-reflective coating will heat up less because it absorbs less sunlight. Our new cool coatings don’t heat up at all because they barely absorb any sunlight and efficiently radiate the heat away.”

With the built environment estimated to be responsible for around 40% of annual global carbon emissions, the technology has the potential to redefine urban cooling in hot climates and help drive the creation of more sustainable buildings.