Design Architecture Why Is Phase-Changing Drywall in the News Instead of in the Home Depot? By Lloyd Alter Design Editor University of Toronto Lloyd Alter is Design Editor for Treehugger and teaches Sustainable Design at Ryerson University in Toronto. our editorial process Facebook Facebook Twitter Twitter Lloyd Alter Updated October 11, 2018 Migrated Image Share Twitter Pinterest Email Design Tiny Homes Architecture Interior Design Green Design Urban Design Americans think of themselves as innovators, but when it comes to green products they are not even in the ballpark. Take phase-changing drywall; we wrote about it almost five years ago in TreeHugger. It works by embedding "phase-changing microcapsules" from BASF and called Micronal into drywall, and is sold in Europe as KNAUF PCM Smartboard. Now National Gypsum is making it in America; Alex Wilson of Greenbuilding Advisor saw it at Greenbuild. But they are not selling it, just doing field trials. Alex describes how it works: National Gypsum's ThermalCORE has fiberglass skins (instead of paper), but otherwise looks no different than standard drywall; the micro-encapsulated PCM spheres are far too small to see. Studies show that the ThermalCORE wallboard stores about 22 BTUs of thermal energy per square foot. The idea is that warmth from the sun during the day will be stored in the wallboard, and then released at night to keep the space warm. It will both help prevent overheating during the day and help reduce heating costs during the evening hours. In essence, it's a high-tech form of thermal-mass materials that are typically used in passive solar design (brick facing walls, tile floors, etc.). National Gypsum has built a nice website but says in their press release that it is not commercially available, but is going through testing in California. But in Europe they have been studying it for years, and in climates like London's and Paris's they found that it could reduce energy consumption by up to 30%. There are architects tools and simulation software available for download. From Micronal brochure, download pdf here They are marketing it with direct comparisons to other, bulkier materials. They note that one gets the effects of thermal mass without as much stuff, and that: As part of a passive cooling concept, construction elements containing Micronal® PCM can in part or completely substitute energy consuming cooling systems. This leads not only to energy savings, but also to a reduction or elimination of in the maintenance and repair costs of the cooling systems, which normally have an average life cycle of 15 years. A simple idea with no moving parts, tested for years already-" a 16-month cyclic test involving 24 temperature cycles per day has attested to a minimum life of 30 years for the material. Its leaktightness and thermal storage characteristics remained unchanged throughout the test period." Why do products like this take forever to come to America, and then years more until we can actually buy it? Why is this in the news instead of in the Home Depot?