"Cooling Paper" technology

[Mij]

The paper can reduce a room's temperature by up to 10 degrees Fahrenheit, making it a radical but effective alternative to today's air conditioners, which consume a lot of power.

Zheng and his colleagues found that the cooling paper can reduce a room’s temperature by as much as 10 degrees Fahrenheit. He selected materials that would reduce the cost of deploying this new technology to cool homes. The process for creating and testing the new material was described in a paper published last month in the American Chemical Society journal Applied Materials & Interfaces. Zheng was awarded a National Science Foundation CAREER Award grant in 2019 for his research.


https://coe.northeastern.edu/news/using-recycled-paper-to-cool-the-air/

 

[Creekside]

Going by the photo, '10 degrees cooler' is due to being more reflective than wood that's painted red or green (fairly poor solar reflectivity). What I'd want to know is the temperature difference between his paper and white paint (regular or designed for solar reflectivity). My guess is that it will be a very small difference. While a micropore material might be a better infra-red emitter, that requires a cool environment to radiate that energy to. If it's a hot day, the IR radiator will probably be absorbing more than it radiates. I think this paper's cooling depends on a lot of conditions that don't apply to real world houses, or are no better than other white coatings.

I replaced my brown asphalt shingles with white metal roofing. Instead of the interior getting significantly hotter than the outside air temperature, it remains at least 3C cooler than the outside air. If you want to stay cool in sunny weather without using energy, I highly recommend a white exterior. BTW, I preferred the light blue roofing, but even that deviation from white meant something like 30% more heat absorption. I'm glad I went with white.