Wednesday 4 November 2020

One Of The Earliest Things,

at school in one of the science lessons,


we were taught, was that white reflects heat, moving on to when we lived in Thailand, one of our friends painted the whole roof of his house white to reflect heat, photographs Purdue University photo/Jared Pike, now engineers at Purdue University recently unveiled a revolutionary white paint that they claim can keep surfaces up to 18 degrees Fahrenheit (7.8 degrees Celsius) cooler than their ambient temperature, by absorbing almost no solar energy and actually sending heat away from the surface it is covering. Think of it as a way of turning basically any space into a refrigerator, only without the energy cost,

“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,” Xiulin Ruan, a professor at Purdue, said, according to researchers, commercially available white paint can reflect just 80%-90% of sunlight and cannot achieve temperatures below their surroundings, while this new reflective white paint reflects 95.5% sunlight and radiates infrared heat much more efficiently,

 an article on the Purdue University website reveals that attempts to create a reflective paint as a feasible alternative to traditional air conditioners can be traced back to the 1970s, which speaks to how difficult finding the right formula actually was. It took Purdue’s engineers six years of hard work and lots of trial and error to come up with a white paint based on calcium carbonate, an earth-abundant compound, that actually worked, “Your air conditioning kicks on mainly due to sunlight heating up the roof and walls and making the inside of your house feel warmer. This paint is basically creating free air conditioning by reflecting that sunlight and offsetting those heat gains from inside your house,” Joseph Peoples, a Purdue Ph.D. student in mechanical engineering and a co-author of the research said, a neat idea indeed, I wonder if you need your local council's permission to paint your roof a different colour?


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