Illinois cooling film kept Houston roofs 40°F cooler without electricity

In Houston, the heat is part of the setting. During the FIFA Fan Festival, though, some of the infrastructure around the event had a rather different experience of the Texas summer. Roofs treated with a thin cooling film stayed dramatically cooler than nearby untreated metal surfaces, even while sitting beneath direct sunlight.The material was not the product of a conventional air-conditioning system or a large energy-consuming installation. As reported by University of Illinois Urbana-Champaign, it came from research led by Lili Cai, a mechanical science and engineering professor at the University of Illinois Urbana-Champaign. A technology developed in her laboratory had moved well beyond controlled experiments, arriving on public infrastructure in one of the world’s biggest sporting events.Illinois researchers develop a film that cools surfaces in sunlightThe principle behind the technology is passive daytime radiative cooling. Rather than using electricity to remove heat, the material is designed to shed thermal energy while exposed to sunlight.That distinction matters in places where roofs, walls and other surfaces can become extremely hot. Conventional cooling can reduce the t...