People like bright rooms but they don’t necessarily like hot rooms. Especially in the summertime. Thankfully, a new window tech could let homeowners hit that Goldilocks ideal. Researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a new nanocrystal whose orientation is flipped by a small electrical charge, which can either block light from coming in — say to keep your living room for movie-watching — let both light and heat in to keep you comfy in the winter, or just blocking the near-infrared, a huge source of heat in our homes during the warm months, without affecting visible light at all.
Via the Berkeley Lab News Center:
At the heart of their technology is a new “designer” electrochromic material, made from nanocrystals of indium tin oxide embedded in a glassy matrix of niobium oxide. The resulting composite material combines two distinct functionalities—one providing control over visible light and the other, control over NIR—but it is more than the sum of its parts. The researchers found a synergistic interaction in the tiny region where glassy matrix meets nanocrystal that increases the potency of the electrochromic effect, which means they can use thinner coatings without compromising performance. The key is that the way atoms connect across the nanocrystal-glass interface causes a structural rearrangement in the glass matrix. The interaction opens up space inside the glass, allowing charge to move in and out more readily. Beyond electrochromic windows, this discovery suggests new opportunities for battery materials where transport of ions through electrodes can be a challenge.
So not only are these smart nanocrystal windows energy efficient, but they’re also relatively green to manufacture. Cooling is a huge electricity issue in the summertime, and by maximizing the sun’s power with the flip of a switch, these new windows could go along way toward decreasing our carbon footprint. And for a person like me, who considers 75 a heat wave but likes a bit of sunshine, the idea that I can block the heat without turning my house into a cave is seriously attractive.
Via [Berkeley Lab News Center]