Air conditioning has transformed the world. Without it, millions of Americans would still be shoveling snow every winter, instead of enjoying the weather in places like our own Southwest Florida. But as we all know, air conditioners require a lot of electricity, and many scientists believe that the energy they use also contributes to climate change. So some have been trying to find ways to cool buildings without A/C.
They may have hit the jackpot. Aaswath Raman, a researcher at Stanford University’s Ginzton Laboratory reported in Nature Magazine that he may have found a way to reflect the sun’s light and heat away from buildings, using mirrors on the roof. When this new technology was recently tested, the building maintained a temperature 4.9 degrees Celsius lower than the outside air. That’s more than eight degrees Fahrenheit cooler, with zero electricity!
Raman and his colleagues applied seven layers of hafnium oxide and silicon dioxide on the roof of the building, and that reflected 97% of the sunlight away from the building. This new technique, which the scientists call photonic radiative cooling, could offer an entirely new, electricity-free, climate-friendly way to cool buildings, and it could be especially important in regions of the world where electricity is rare or undependable.
Don’t expect to be using this next week or next month, though. The researchers need to figure out how to remove heat from buildings, too, not just keep heat out. But it is a start, and it could be exciting. Meanwhile, you’ll have to keep your air conditioning in good working order. For that, you can call D and D.