Radiative cooling: harness sustainable coldness from the universe for passive cooling on the Earth

Professor Yao Zhai
Physics 223A
Professor Andrew Meng


Radiative cooling is a passive cooling technique featured with zero-energy consumption by emitting terrestrial heat to the universe in form of blackbody thermal radiation. Nocturnal radiative cooling is an ordinary phenomenon of radiative cooling effect happening during a clear and calm night, but day-time sub-ambient radiative cooling material, which can cool an object’s surface temperature below ambient air temperature, has never been found in nature. The first realization day-time radiative cooler has been demonstrated by optimizing spectroscopic property of its surface from ultra-violet to mid-infrared, and indicates the day-time sub-ambient radiative cooling material is a promising cooling solution to save energy from current cooling facilities, such as air conditioners. Therefore, a scalable, low-cost day-time sub-ambient radiative cooling material is demanded to mitigate energy demand in large-scale thermal management systems. In this talk, Dr. Zhai will introduce his research projects related to day-time sub-ambient radiative cooling materials and systems, including scalable-manufactured optical metamaterial, kilo-watt scale radiative cooling collection and storage system, as well as radiative cooling structural materials. He will also discuss potential applications of day-time sub-ambient radiative cooling materials in renewable energy generation, environment sustainability and space cooling in buildings.


Dr. Zhai is an assistant professor in the Department of Mechanical & Aerospace Engineering at the University of Missouri Columbia. Dr. Zhai received his PhD degree from the University of Colorado Boulder and continued his postdoc in the National Institute of Standards and Technology. Dr. Zhai’s research interests focus on investigating novel optical materials with unprecedented properties and developing advanced manufacturing technologies to transform these materials into practical solutions in real-world applications in energy, thermal management, environment sustainability.