Revolutionary Vacuum Glass Coming from Guardian
Revolutionary vacuum-insulated glass coming from Guardian provides an insulating value of R-12.
Guardian Industries, one of the world’s largest architectural and automotive glass manufacturers, with 19,000 employees in 25 countries, has under development a revolutionary vacuum-glazing panel that provides a center-of-glass insulating value of R-12 to R-13. The glass—Guardian VIG (for vacuum-insulated glass)—has a very thin (250-micron or 0.25-mm) space evacuated to 10–4 torr (for reference, thermos bottles typically have a much harder vacuum of around 10–6 torr) between two layers of glass, one of which has a low-emissivity (low-e) coating. Guardian is currently producing the vacuum glazing on a limited basis for testing and hopes to roll it out commercially by the end of 2009.
Heat travels in three modes, and the vacuum effectively eliminates two of them: conduction and convection. But the vacuum doesn’t eliminate radiation, so the low-e coating is critical to the unit’s performance, according to Scott Thomsen, the chief technology officer and group vice president of Guardian’s Science and Technology Center. The type of low-e coating also has a huge effect: a hard-coat (pyrolytic) coating yields only R-2 to R-3 insulation, and standard low-e coating yields R-4, Thomsen told EBN. To achieve R-12, Guardian uses its more advanced ClimaGuard Low-E glass, which has two deposited metallic layers like Cardinal’s LoE2. Energy performance testing of the Guardian VIG panels has been done at the University of Waterloo in Ontario.
Published February 3, 2008
Wilson, A. (2008, February 3). Revolutionary Vacuum Glass Coming from Guardian. Retrieved from https://www.buildinggreen.com/news-analysis/revolutionary-vacuum-glass-coming-guardian