The porous polymer coatings, which switch from white to transparent when wetted, can be put into plastic enclosures to make panels that control light and temperatures of buildings. Credit: Jyotirmoy Mandal/Columbia Engineering
Buildings devote more than 30% of their energy use to heating, cooling, and lighting systems. Passive designs such as cool roof paints have gone a long way toward reducing this usage, and its impact on the environment and climate, but they have one key limitation—they are usually static, and thus not responsive to daily or seasonal changes.
Columbia Engineering researchers have developed porous polymer coatings (PPCs) that enable inexpensive and scalable ways to control light and heat in buildings. They took advantage of the optical switchability of PPCs in the solar wavelengths to regulate solar heating and daylighting, and extended the concept to thermal infrared wavelengths to modulate heat radiated by objects. Their work is published on October 21, 2019 by Joule.