Scientists Create "Cooling Glass" Technology to Combat Climate Change by Expelling Building Heat to Space

University of Maryland researchers have developed a revolutionary "cooling glass," offering an eco-friendly means of reducing indoor heat and carbon emissions. This marks a significant leap forward in green building technology.

The University of Maryland team conceptualized an inventive "cooling glass" that can decrease indoor temperatures without electricity. This revolutionary material operates by extracting chill from space.

The cutting-edge technology entails a microporous glass coating, as detailed in an article in the Science journal. This coating can decrease the temperature of the material under it by 3.5 degrees Celsius at midday. Additionally, it could potentially reduce a mid-rise apartment building's annual carbon emissions by 10%, stated the research team led by Distinguished University Professor Liangbing Hu, Department of Materials Science and Engineering.

The coating has a dual functioning mechanism. Firstly, it reflects nearly 99% of solar radiation, preventing buildings from heating up. More notably, it discharges heat as longwave infrared radiation into the freezing universe, where the temperature is routinely around -270 degrees Celsius. This is just slightly above absolute zero.

Through a process known as "radiative cooling," space serves as a heat sink for buildings. Buildings can capitalize on the innovative cooling glass design—the atmospheric transparency window, a feature of the electromagnetic spectrum that passes through the atmosphere without increasing its temperature—to dispel large quantities of heat into the limitless cold sky. This is the same process that enables the earth to cool itself, particularly on clear nights, although the emissions from the newly developed UMD glass are much stronger.

“This is a revolutionary technology that greatly simplifies how we can cool and make our buildings more energy efficient,” stated Assistant Research Scientist Xinpeng Zhao, the study's lead author. “This could modify the way we exist and assist us in better caring for our home and our planet.”

Unlike past cooling coatings, the newly developed UMD glass is environmentally stable—resistant to water, ultraviolet radiation, dirt, and even flames, enduring temperatures of up to 1,000 degrees Celsius. The glass can coat various surfaces, such as tile, brick, and metal, rendering the technology scalable and adaptable for extensive use.

The group used finely ground glass particles as a binder to bypass polymers and strengthen its outdoor durability, according to Zhao. In addition, they selected the particle size to optimize the emission of infrared heat while concurrently reflecting sunlight.

Developing the cooling glass conforms with worldwide efforts to cut down energy usage and combat climate change, Hu noted. He highlighted that this year's Fourth of July may have been the warmest day globally in 125,000 years.

“This ‘cooling glass’ is more than simply a novel material—it's a crucial aspect of the solution to climate change,” he added. “By reducing air conditioner use, we’re making great strides toward consuming less energy and decreasing our carbon footprint. It underscores how new technology can assist us in constructing a cooler, more sustainable world.”

Besides Hu and Zhao, Professor Jelena Srebric from the mechanical engineering department and Professor Zongfu Yu from the University of Wisconsin-Madison's Department of Electrical and Computer Engineering are study co-authors. They contributed their expertise on building CO2 savings and structure design, respectively.

The team is currently concentrating on further testing and practical applications of their cooling glass. They are hopeful about its commercialization prospects and have launched a startup, CeraCool, to upscale and commercialize it.