Top Products from the Greenbuild Expo Floor: Windows
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Renovate, from Berkowitz, LLC. is a retrofit glazing that fits on the interior of single-pane commercial windows, improving the center of glass U-factor from 1.03 to 0.16. Finding the top Greenbuild products among 900 exhibitors ... R-20 (!) quadruple-pane windows As always, there were quite a few companies offering windows/glazing with impressive U-factors. Southwall's Heat Mirror film has been around for years, but the company is now offering a quadruple-glazed unit with a ridiculously low center-of-glass U-factor of 0.05 (or R-20, which is better than many walls!). This is a krypton-filled unit with a visible light transmittance of 0.53 and solar heat gain of 0.38--not bad for three layers of film. And Southwall can incorporate different films and coatings depending on need. This glass is available in Duxton fiberglass windows. A high-performance window retrofit Traco manufactures the entire OptiQ line from frame to glazing, which helps keep this triple glazed window cost competitive. PPG had another interesting window, a retrofit window named Renovate that is sold through Berkowitz, LLC. There are a lot of single-glazed, energy-wasting commercial windows out there, and replacing them is expensive. These retrofit windows install on the interior, and are made from PPG's low-e glass, low-e coating, and a ½" argon-filled space. A spacer containing a desiccant separates this unit from the original pane. This system takes a ¼" single-pane monolithic window and improves the center-of-glass U-factor from 1.03 to 0.16. Renovate can be installed with minimal disruption to building occupants. Cost-competitive triple glazing Traco, a division of Kawneer, had its OptiQ triple-glazed window at Greenbuild as well. Developed with assistance from the U.S. Department of Energy, this window has center-of-glass U-factors of 0.17 and 0.22 for fixed and operable units. According to the company, these are commercially available windows, and unlike some high-performance windows, are cost competitive because Traco makes the entire window and does not outsource the glazing. Thermochromic self-tinting panes One of the most interesting window products at the show was Pleotint, a thermochromic "Sunlight Responsive Tinting" (SRT) film that is sandwiched between two layers of glass and installed as the exterior panel of glass in an IGU. You could see Pleotint at three different booths: Pleotint's (of course), PPG's (which is co-marketing Pleotint), and Southwall, which is incorporating the material into its glass units. In general, Pleotint is clear in indirect light and tints in direct sunlight, but more specifically it reacts to temperature. It is at its darkest at 149°F (65°C) and is clear again at 77°F (25°C). Pleotint's tint range cannot be adjusted for temperature, however, and there are still questions about performance in extreme climates and lifespan, but this is a promising technology that offers a lower-cost, less complicated option to electrochromic tint windows. Next week we'll take a look at a couple of natural insulation options, water-efficient products, and some interesting uses of recycled content.