University of Colorado Boulder and University of Wyoming engineers have successfully scaled up an innovative water-cooling system capable of providing continuous day-and-night radiative cooling for structures.
The advance could increase the efficiency of power generation plants in summer and lead to more efficient, environmentally-friendly temperature control for homes, businesses, utilities and industries.
The new research demonstrates how the low-cost hybrid organic-inorganic radiative cooling metamaterial, which debuted in 2017, can be scaled into a roughly 140-square-foot array--small enough to fit on most rooftops--and act as a kind of natural air conditioner with almost no consumption of electricity.
"As Earth's temperature warms due to the absorbed heat from the sunlight during the day, it continuously emits infrared light to the cold universe all the time," said Professor Ronggui Yang of Mechanical Engineering and lead author of the study.
"During the night, Earth cools down due to the emission without the sunshine."
The researchers' film-like material reflects incoming almost all sunlight while still allowing an object's stored heat to escape as much as possible, keeping it cooler than ambient air even in the midday sun.