A new material created by researchers could offer an affordable, environmentally friendly alternative for cooling homes and other buildings, according to BBC News. Using a reflective material made from glass and polymers, about the thickness of aluminum foil, scientists have kept water more than 10 degrees Celsius cooler than the surrounding air during the warmest part of the day.
Air conditioning accounts for around ten percent of the world’s total energy use, and also releases its own greenhouse gases, called hydrofluorocarbons or HFCs. In 2016, over 150 countries agreed to phase out their use of HFCs within 15 to 20 years. HFCs were first favored to replace earlier cooling substances that were causing a hole in the ozone layer. However, they present their own risks when it comes to the emissions that cause climate change.
The researchers, at Colorado University, Boulder, first published their findings on the material in 2016. Now, they have published further research having improved the material and built an array of panels small enough to fit on the average rooftop.
“You could place these panels on the roof of a single-family home and satisfy its cooling requirements,” according to the study’s lead author, Dongliang Zhao, of CU Boulder’s Department of Mechanical Engineering.
The researchers tested the material in a range of weather conditions.
“We can now apply these materials on building rooftops, and even build large-scale water cooling systems with significant advantages over the conventional air-conditioning systems, which require high amounts of electricity to function,” said University of Wyoming Associate Professor Gang Tan, another author.
The material reflects most of the Sun’s light that otherwise heat buildings. When used to cover water, it also allows heat in the water to escape. With this heat escaping, and no new heat allowed to replace it, it can quickly have a cooling effect.
To produce the material glass microspheres are built into a polymer film with a silver coating. The material just 50 micrometers thick and can be manufactured on rolls like aluminum foil, making it easy to put in place.
In addition to homes, the authors of the study say the material could be used for cooling data centers and thermoelectric power plants, which require high quantities of water and energy to keep machinery cool.
The International Energy Agency says air conditioning is on track to use triple its current amount of electricity by 2050.