t’s estimated that 10 percent of all the energy used in buildings in the U.S. can be attributed to window performance, costing building owners about $50 billion annually, yet the high cost of replacing windows or retrofitting them with an energy efficient coating is a major deterrent. U.S. Dept. of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) researchers are seeking to address this problem with creative chemistry—a polymer heat-reflective coating that can be painted on at one-tenth the cost.
Berkeley Lab’s paintable window coating is based on brush block copolymers that rapidly self-assemble to photonic crystals, which are easily tunable across the entire spectrum of solar energy. Image credit: Garret Miyake, University of Colorado
Berkeley Lab’s paintable window coating is based on brush block copolymers that rapidly self-assemble to photonic crystals, which are easily tunable across the entire spectrum of solar energy. Image credit: Garret Miyake, University of Colorado
“Instead of hiring expensive contractors, a homeowner could go to the local hardware store, buy the coating, and paint it on as a DIY retrofit—that’s the vision,” said Berkeley Lab scientist Raymond Weitekamp. “The coating will selectively reflect the infrared solar energy back to the sky while allowing visible light to pass through, which will drastically improve the energy efficiency of windows, particularly in warm climates and southern climates, where a significant fraction of energy usage goes to air conditioning.”