• At the Glass Association of North America’s (GANA) Fall Conference last week, Jon Kimberlain of Dow Corning, BEC division chair, referenced the ESPN “30 for 30” series, in which they take an in-depth look at the background of sporting events. The tag line for these documentaries is “what if.”

    In that spirit, “What if you knew how much GANA does to support our industry every day, would that change your perspective on the organization?” I’ve been a big fan of GANA’s for a long time. Last week only reinforced that. Again.

    It’s going to take several blogs to deal with the high points covered. I’m looking at my notes (nine pages over roughly two days), and some of this is going to take several weeks just to cover one division. So here goes with Part 1, dealing with the laminating division.

    Prior to taking the tour through the Intertek laboratory, Valerie Block with Kuraray Interlayer Solutions gave an update on the tornado-related code changes that are in the offing. They’re much the same as what we’re used to in the hurricane arena: small-, large-missile testing, but with two notable exceptions:  the loads are greater, and there’s no need for cycling.

    Wind loads in a tornado are 14 times greater than they are in a Level D hurricane design, so while the hurricane large missile test (ASTM E1886) calls for a nine-pound, 2-by-4 shot out a cannon at 35 miles-per-hour, tornado testing calls for a 15-pound 2-by-4 at 100 miles-per-hour. Essential buildings (e.g., schools, hospitals, tornado shelters, police and fire stations) are the intended targets for cladding upgrades, not just glass, but also brick, stone, precast, etc. The cycling durations we are used to in the window/hurricane testing are eliminated, as tornado events are too short to justify cycling. But, the glass must remain in the opening and not allow penetration of the missile through the glass. More to come on this front as the codes take shape.

    The laminated glass, interlayer manufacturers and fabricators are working on several fronts in response to inquiries from the architects for laminated glass that can:

    • respond to energy and sound;
    • be available in larger lites with minimal support;
    • offer ultra-clear glass in lami constructions;
    • enable cold, warm, and hot bending; and
    • protect birds.

    Further, the industry is looking at how thick laminated glass can be, if there’s differences between annealed, heat-strengthened or tempered laminated glass, and incorporating the above functionality into a single glass lite. I discussed multi-purpose glass in a previous post.

    ASTM E1300 relating to the strength of glass for wind load is a little weak when it comes to both minimally supported (think spider or patch fittings) and thick constructions. A standard for glass walkways is also being developed, since many of these incorporate laminated glass.

    Edge quality is an issue. We talked previously about how to get laminated glass edges aligned, and it’s not clear if there’s going to be a standard about this, or if the individual lami fabricators are going to have to address it. There was some discussion about post-lamination glass edge fabrication, but interlayer folks are looking into what the fluids used for creating the edging on the glass will do to the interlayer. Long term exposure to these fluids (such as alcohol, water, etc.) is one concern that was expressed. Obviously, any heat treating of the glass prior to lamination eliminates the ability to do post-lamination edging, so that leaves post-lami edging to annealed, but annealed may not be acceptable for guardrail or handrail applications. This issue has to settle down, too; for now it’s not clear where the movement in the marketplace will take this.

    On something of a more serious note: Codes and standards can only address “current knowledge.” As we saw last year at BEC in James O’Callahan’s presentation, there are folks pushing the envelope on what glass can do. We get asked the same sort of thing of our framing products at TGP, I’m sure everyone does, such as, “how big of a lite of glass can you support?”

    Any and all of the standards groups—GANA, AAMA, ASTM, etc.—have a tough time staying ahead of the curve. The architects and designers keep asking more and more of all the materials associated with glazing, not just glass. Smaller frame members, less edge or smaller point supports of glass, can we up the design strength of structural sealants, etc.

    So while GANA is accomplishing a lot to support the glass industry, please make sure the manufacturers who call on your company know where you see the market going, and what new and different things you’re being asked to do. BEC is the only part of GANA with direct ties to the glazing subcontractors who in the end put all of our industry’s products (glass, framing, sealants, gaskets) into service on every project.

    We have to know where we can help you. It may require a more active role in helping us head in the right direction. So, with a final nod to ESPN, “What if you were to ask not what GANA can do for you, but what can you do to support GANA’s efforts to develop these codes and standards?”

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  • Here it is October, and it’s tough to know where the year has gone. Events in the industry appear to fly by, also. Several in recent days are worth noting.

    Wired glass: The 600-student junior/senior high school I attended had two fire stairs with wired glass partitions of a substantial size – something you don’t see often today as codes have become more stringent. If you missed it, USGlass reported last week that ANSI is further restricting the material’s use. Fortunately, though, our industry has many excellent alternatives that meet both fire safety and impact safety requirements.

    An Armed Forces Career Center in Cullman, Alabama, has installed bullet-resistant (not bullet-proof) glass in a shopping center. The remarkable part here is that the building owner did this on his own, with no prompting from the tenants. The part that caught my eye is that the owner is a 95 year old WWII vet. Thank you, sir, for your service, and more importantly, thank you for doing the right thing with your building. Can we get some more of this, please? I know of one center in Overland Park, Kansas, with the same need.

    In past blogs I’ve discussed my trepidation with glass-bottomed anything. If you recall, I’m not going on it. Period. New to the world is this suspension bridge in China, where the wood planks have all been replaced with glass. I hope there are detour signs at each end for alternate routes, or there are plans to build a wood bridge next to it. Shortcut or not, I’m highly attracted to the alternate route. Hopefully there is one.

    Seeing as the Chinese president was in Washington, DC, recently, this one caught my eye about the European Union potentially granting China Market Economy Status. This would likely “increase manufactured imports from China by 25-50 percent,” and “…will raise pressure on the United States…to follow suit.” At-risk industries if the MES is granted could include glass, aluminum and steel. Given the past statements of a certain U.S. presidential candidate about glass and window imports from China for his U.S. and Canada projects, this one might be worthy of a letter to your congressman and senators.

    With the GANA Fall Conference starting in less than two weeks, please tell the appropriate GANA division or technical committee chairs or GANA staff of any issues you think should be considered. My next blog will probably be written on the plane back from San Antonio.

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  • Field Notes 10.09.2015 1 Comment

     

    The title of this ARS Technica article – “Quantum dots may be key to turning windows into photovoltaics” – somehow, all of a sudden, connected some dots in my gray matter.  Perhaps the PV panel and glass combination described will provide some other benefits that would make future glass more multi-functional than it already is. As if keeping air and water out isn’t enough, we all know that glass provides exterior views and also has to perform a huge role in thermal performance of facades.  What if we added a couple more items to that list? Interested?

    I’ve been a proponent of photovoltaic glazing and am curious how efficient a fixed glazing lite can be, because as I understand it, with current technology, the PV panels are only 100-percent efficient when perpendicular to the sun’s rays.  Vertical glass walls are not built to follow the sun’s rays, so the opportunity to be in position to be 100-percent efficient isn’t there. But, these researchers have taken a different approach, albeit not the “connecting the dots” I envision.

    The 12-centimeter (4.72-inch) square PV panels are embedded either in a film or coated to the glass provide some degree of shading, much like applied ceramic frit or silk-screened patterns. With the PVs, a shading coefficient is built in. Their experiments shaded 10 percent and 20 percent of the available solar energy. Not only that, if the PV panels are such that birds can see them, we’ve just solved the bird-strike issue, too. The unknown might be finding a pattern of installing the PV cells on the glass that deters birds from impacting the glass.

    The last dot: I wonder what the actual power contribution could be. Because, if the rate of return is such that more of this glass can contribute to lessening a building’s need for grid-supplied power, ASHRAE won’t ever win the “battle for the wall” (reducing the amount of vision glass comprising the exterior) we saw in 2013-14.

    As always, there are a couple of items on the other side of the coin to address. Shading coefficients reduce natural light coming through the glass. How does that impact lighting requirements? Or, is enough energy generated from the PV panels to offset that? Is putting more money into the glass able to be offset and more importantly pay back the initial cost by decreasing lighting power requirements? And, what is the appearance of this glass from the interior? Does enough of the view remain, and is there enough openness to the glass to be aesthetically appealing?

    Another approach might lead to exterior mounted sunshade PV devices that can more efficiently convert solar energy into power simply by adding mechanical tracking to their design, so that panels are no longer locked in place, and can be more efficient by tracking the movement of the sun across the sky.  There’s a shading benefit these sunshades could well add to the design of a façade, obviously. If they’re collecting sunlight for energy conversion, that’s light and energy that’s not going into or through the wall. Converting them to bird-strike deterrence might be a reach.

    Better minds than mine have a lot to do to combine these factors into one cohesive product. But, bring on the INCREASED multi-functionality of glass.  It’ll be a major weapon going forward in keeping glass as a significant element in future building design and construction.

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