Summer! It's a wonderful time but a hot one! Indeed, most would argue that you cannot survive summer without some good air conditioning. But what if your buildings or cars never heated up?
Purdue University engineers have developed a white paint that can keep all surfaces cool — specifically, up to 18 degrees Fahrenheit (roughly 10 °C) cooler than their ambient surroundings. Moreover, the "super-white" paint reflects 95.5% sunlight and efficiently radiates infrared heat.
Acts almost like a refrigerator without consuming any energy
"It’s very counterintuitive for a surface in direct sunlight to be cooler than the temperature your local weather station reports for that area, but we’ve shown this to be possible," said Xiulin Ruan, a Purdue professor of mechanical engineering.
The paint works by absorbing nearly no solar energy and sending heat away from wherever it is used. It can even help with climate change by sending heat away from Earth into deep space where it can no longer affect our planet.
"We’re not moving heat from the surface to the atmosphere. We’re just dumping it all out into the universe, which is an infinite heat sink," said Xiangyu Li, a postdoctoral researcher at the Massachusetts Institute of Technology who worked on this project as a Ph.D. student in Ruan’s lab.
Experiments proved its efficacy
To prove the efficacy of their new product, the Purdue researchers took infrared camera images of their paint compared to regular white paint in rooftop experiments. The results were nothing short of impressive.
“An infrared camera gives you a temperature reading just like a thermometer would to judge if someone has a fever. These readings confirmed that our paint has a lower temperature than both its surroundings and the commercial counterpart,” Ruan said.
You can watch the experiment with detailed explanations down below:
The experiment proved that Purdue's novel paint can maintain a lower temperature under direct sunlight and reflect more ultraviolet rays. Now, imagine this paint used all over our cities on all buildings and roads. Wouldn't that be a creative way to fight global warming?
Editor's note: An earlier version of this article stated the new white paint can cool surface temperatures up to 18 degrees Fahrenheit, or "-7.778" degrees Celsius. This is incorrect — since a different conversion is needed for temperature changes, as opposed to an absolute temperature. The correct conversion for a drop in 18 degrees Fahrenheit to metric is roughly 10 °C. IE regrets this error.