New car paint could replace air conditioning

A new paint developed by scientists can make a car's interior cooler even when exposed to high temperatures. Said paint can also be used on buildings or houses.

Never needing a car, even when it's 100-degree heat, would be a great idea, and while it sounds impossible, it can be a reality. A newly created new paint formula could help make buildings and cars less dependent on air conditioners..

Purdue University engineers have created a revolutionary paint. This is the whitest white ever made. Now, researchers say applying this paint to cars or buildings reduces the need for air conditioning.

Ultra-white paint formula keeps whatever it's painted on much cooler

Purdue's ultra-white paint formula keeps everything painted fresh. “If you were to use this paint on a roof covering about 1,000 square feet, we estimate that you could get 10 kilowatts of cooling capacity,” Xiuling Ruan, professor of mechanical engineering at Purdue, told Scitechdaily. “This is more powerful than the central air conditioners used in most homes,” he noted.

You probably remember Vantablack, that black paint that absorbs 99% of visible light. Well, this whiter white paint is the exact opposite of Vantablack. That is, it reflects 98.1% of the sun's rays.

It took six years of research to find the whitest white paint. Actually, originates from research conducted in the 1970s.. At that time, research was underway to develop a radioactive cooling paint.

How does it work?

Infrared heat escapes from everything that is painted white. This is the complete opposite of the reaction of typical white paint. It gets warmer, not colder, unless it's specifically designed to dissipate heat.

This specially formulated white paint only reflects 80-90% of sunlight. And does not cool the surface on which it is drawn. This also means that it does not cool what surrounds this type of paint.

So what makes this whitest white so extraordinarily white? It is barium sulfate that increases its cooling properties. Barium sulfate is also used in the production of photographic paper, and is what makes some cosmetics white.

Using barium sulfate makes things more reflective

“We looked at various commercial products, basically anything that is white,” said Xiangyu Li, Ph.D. at Purdue. student in Rouen's laboratory. “We found that by using barium sulfate, you could theoretically make things really highly reflective. This means they are very, very white,” he said.

Another reason why white paint is so reflective is because barium sulfate particles are of different sizes. Larger particles of barium sulfate scatter light better. Therefore, different particle sizes help to further scatter the sunlight spectrum.

The concentration of particles in paint is the best way to make white so reflective. But the disadvantage is that higher concentrations of particles make it easier to peel off the paint. So, from a practical standpoint, being white paint isn't particularly good.

Paint has been found to cool painted surfaces. At night, the paint keeps surfaces 19 degrees cooler than anything else that surrounds the painted object. In conditions of extreme heat, it cools the surface 8 degrees lower than the surrounding objects.

We wonder how much lower temperatures can be reduced with more experimentation. If these experiments with white paint could lower the temperature even further, the air conditioner might become obsolete. Or at least reduce the need to turn on the air in the car or at home.

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