Imagine there is a paint that cools a building so much that air conditioning is no longer needed. That is exactly what a research team from Perdue University in West Lafayette, Indiana (USA) has introduced. They have developed a white paint that keeps surfaces 7 degrees Celsius cooler, than untreated surfaces.
A big step forward
Existing heat-repellent paints reflect 80% -90% of sunlight. The white paint created by the Purdue researchers reflects 95.5% sunlight. After six years of research, the team arrived at a formula made from calcium carbonate, a compound commonly found in rocks and shells.
This compound, used as a filler for the paint, ensures that the final product behaves similarly to commercially available white paint. But with greatly improved cooling properties. These calcium carbonate fillers absorb almost no ultraviolet radiation. In addition, the researchers estimate that the production of the paint will be cheaper than similar products.
Actually quite simple
"As sunlight heats the roof and walls, it gets warmer inside the house. That activates air conditioning. The paint is basically a free air conditioner. The sunlight is reflected and the heat gains are offset from inside," said Joseph Peoples, a Purdue Ph.D. student in mechanical engineering and co-author of the report. "Reducing the use of air conditioning has a number of sustainability benefits. For example, using less energy has a beneficial impact on carbon dioxide emissions. We are still researching the effects of this."
Source: Perdue University. Photo: Jared Pike
