Scientists Create ‘Cooling Glass’ Coating Tech
A new “cooling glass” technology from the University of Maryland aims to combat rising global temperatures by turning down indoor heat without electricity.
The microporous glass coating, published in the journal Science, can reportedly lower the temperature of the material beneath it by 3.5 degrees Celsius at noon.
“It’s a game-changing technology that simplifies how we keep buildings cool and energy-efficient,” said Assistant Research Scientist Xinpeng Zhao, the first author of the study. “This could change the way we live and help us take better care of our home and our planet.”
About the Glass
According to UMD’s news release, the coating reflects up to 99% of solar radiation to stop buildings from absorbing heat. Additionally, it emits heat in the form of longwave infrared radiation into space, where the temperature is generally around -270 C, or just a few degrees above absolute zero.
This phenomenon is known as “radiative cooling,” where space effectively acts as a heat sink for the buildings.
The new cooling glass design along with the “atmospheric transparency window,” or a part of the electromagnetic spectrum that passes through the atmosphere without boosting its temperature, can send large amounts of heat into the cold sky.
Professor in the Department of Materials Science and Engineering Liangbing Hu, who led the project, says that the coating has the potential to reduce a mid-rise apartment building’s yearly carbon emissions by 10%.
The new glass is reportedly able to withstand exposure to water, ultraviolet radiation, dirt and flames, enduring temperatures of up to 1,000 degrees C. The glass coating can be applied to a variety of surfaces such as tile, brick and metal.
Zhao explained that the team used finely ground glass particles as a binder, allowing them to avoid polymers and enhance its long-term durability outdoors. They reportedly chose the particle size to maximize emission of infrared heat while simultaneously reflecting sunlight.
The development of the cooling glass aligns with global efforts to cut energy consumption and fight climate change, said Hu, pointing to recent reports that this year’s Fourth of July fell on what may have been the hottest day globally in 125,000 years.
“This ‘cooling glass’ is more than a new material—it's a key part of the solution to climate change,” he said. “By cutting down on air conditioning use, we're taking big steps toward using less energy and reducing our carbon footprint. It shows how new technology can help us build a cooler, greener world.”
According to the university, mechanical engineering Professor Jelena Srebric and Professor Zongfu Yu from the Department of Electrical and Computer Engineering at the University of Wisconsin-Madison are also co-authors of this study. They reportedly contributed their expertise on building carbon dioxide savings and structure design, respectively.
Now, UMD says that the team is focusing on further testing and practical applications, with optimism for the commercialization prospects. Additionally, they have created the startup company CeraCool to scale up and commercialize the coating.
Other Glass Coatings Studies
In February, a new multilayered fluidic system inspired by the skin of a squid species was developed by researchers at the University of Toronto that reportedly has the potential to reduce energy costs in buildings. The research team also included associate professor Ben Hatton, Ph.D. candidate Charlie Katrycz and assistant professor Alstan Jakubiec.
U of T reports that current “smart” building technologies, like automatic blinds or electrochromic windows, can be used to control the amount of sunlight that enters a room. However, Kay says that these systems are limited in that they cannot differentiate between different wavelengths of light or can control how that light gets distributed spatially.
As an alternative, the team developed a platform that optimizes the wavelength, intensity and dispersion of light transmitted through windows using microfluidics. The prototypes reportedly consist of flat sheets of plastic that are permeated with an array of millimeter-thick channels to pump fluids through.
Then, customized pigments, particles or other molecules can be mixed into the fluids to control what kind of light gets through and in what direction the light is distributed. The sheets can also be combined into a multi-layered stack with different optical functions, such as controlling intensity, filtering wavelength or tuning the scattering of transmitted light indoors.
This method can be digitally controlled by pumps to add or remove fluids from each layer, optimizing light transmission within the system.
U of T researchers reportedly built detailed computer models that analyzed the potential energy impact of covering a hypothetical building in this type of dynamic façade, informed by physical properties measured from their prototypes. The team also then simulated various control algorithms for activating or deactivating the layers in response to changing ambient conditions.