[imagesource: Purdue University / Jared Pike]

That white is so blinding!

No, actually, it is cooling.

See that man in the image above? His name is Xiulin Ruan and he and his team have just created the whitest white (which is the white paint you see him holding up).

They have just demonstrated how colour doesn’t just appear to make things look pretty, but is also a valuable technology.

You know how people prefer to wear white in the heat because it’s a better colour to keep you cool, or stay away from black if it’s hot because that colour absorbs all the heat?

Well, some engineers from Purdue University are taking this science even further; creating the coolest white to ever exist, turning it into paint, and using it to cool down buildings better than air conditioning can.

Ruan and his team made ultra-white paint a while back and now after six years of research, has topped that achievement.

This is the whitest paint to ever exist and it can keep surfaces cooler than the formulation that researchers had previously demonstrated:

“If you were to use this paint to cover a roof area of about 1 000 square feet, we estimate that you could get a cooling power of 10 kilowatts.

That’s more powerful than the central air conditioners used by most houses,” said Ruan.

On the other end of the spectrum is the blackest black, ‘Vantablack’, which absorbs up to 99,9% of visible light.

The new whitest paint formulation reflects up to 98,1% of sunlight – compared with the 95,5% of sunlight reflected by the researchers’ previous ultra-white paint – and sends infrared heat away from a surface at the same time, according to Purdue.

Other white paints on the market at the moment can’t reflect sunlight and heat at anything near the rate that this new white can:

The researchers demonstrated outdoors that the paint can keep surfaces around -7 degrees Celsius cooler than their ambient surroundings at night.

It can also cool surfaces -8°C below their surroundings under strong sunlight during noon hours.

This is a good thing for fighting climate change because it could mean less electricity gets used for air conditioning and other things you may use to keep things cool.

Here’s more from New Scientist:

The amount of sunlight absorbed by the new paint is lower than the amount of energy it radiates through our atmosphere and into deep space, so the material actually becomes cooler than its surroundings. The team plans to carry out experiments with painted tubes carrying water and hopes to create an electricity-free refrigeration effect.

Ruan says there is another positive effect because the paint sends energy away from our planet:

“We send the heat to space, we’re not leaving the heat on Earth,” he says.

“Traditional air conditioners leave the heat on Earth’s surface, it’s just moved from the inside of your house to the outside.”

Who knew that white paint could be so powerful?

Speaking of immensely powerful colours, we also have something on the colour red.

[source:purdueuniversity&newscientist]