See-through film rejects 70 percent of incoming solar heat

Engineers have developed a heat-rejecting film that could be applied to a building's windows to reflect up to 70 percent of the sun's incoming heat. The film is able to remain highly transparent below 32 degrees Celsius, or 89 degrees Fahrenheit. They estimate that if every exterior-facing window in a building were covered in this film, the building's air conditioning and energy costs could drop by 10 percent.

from Top Technology News -- ScienceDaily https://www.sciencedaily.com/releases/2018/11/181108142354.htm