by Shane Henson — October 14, 2011—Southwall Technologies Inc., a global developer and manufacturer of energy-saving films and glass products, recently announced what it calls the world’s highest-performing insulating glass (IG), reportedly offering the best performance of any commercially available product in the world.
The new Heat Mirror “Quad-Cavity” R-20 IG achieves a remarkable 0.05 center of glass U-factor (R-20 insulating value) at the same weight as standard dual-pane IG, enabling a new generation of zero-energy windows.
The product could be used in a wide variety of buildings and will likely be of interest to facilities managers and owners in all industries and climates looking for innovative ways to conserve energy, whether at the time of construction or for a renovation project.
According to studies conducted by the Lawrence Berkeley National Laboratory and funded by the U.S. Department of Energy, “superwindows”—windows with at least R-8 total unit insulating performance and moderate solar heat gain—can become more energy-efficient than insulated walls due to the added benefit of passive solar heating, in which heat from the sun is used to further reduce the heating load on the HVAC system. Unlike walls, highly-insulating windows can actually achieve a net energy gain by admitting more heat from the sun than they lose through conduction.
Heat Mirror film technology utilizes nanoscale metal coatings to reflect heat back to its source and improve the insulating performance of glass. One or more lightweight Heat Mirror films can be suspended inside of an insulating glass unit to create two, three or even four super-insulating cavities without adding weight. The Quad-Cavity R-20 product suspends three lightweight Heat Mirror films within the IG unit, creating four independent and super-insulating airspaces, also called cavities.
When configured in a 1-3/4″ overall IG unit thickness with Krypton gas fill and low-emissivity (“low-e”) coatings on the second and tenth glass surfaces, the Quad-Cavity product meets a 0.05 center of glass U-factor and 0.09 full-unit U-factor for a typical light commercial fixed fiberglass window. Different combinations of film and low-e glass can be used to optimize performance for either maximum solar heating in cold climates or maximum solar shading in warm climates.
