BOULDER, COLORADO — Researchers at the University of Colorado in Boulder have invented a film that can cool buildings without using any power.

The new material measures 50 micrometers in width, which is slightly thicker than kitchen aluminium foil. It consists of a transparent polymer, tiny glass beads and a silver layer.

The silver layer reflects sunlight through the plastic, preventing it from heating the building while the glass beads constantly emit infrared light and heat through a process called passive radiation cooling.

The cooling effect is said to be able to keep the internal temperature of a home at 20 degrees Celsius when the outside temperature is 37 degrees, the Economist reported.

"We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology," Xiaobo Yin, co-director of the research and an assistant professor at the university, said in a press release.