For the glass industry, keeping window-wall ratios (WWR) in our favor is something of a constant battle.
Two forces are at play here. In the design world, glass—including large, complex curtainwall systems and facades—is in demand. And as technology has evolved, it’s become more and more attainable to deliver the necessary thermal efficiency. Meanwhile, increasingly stringent codes continue to see greater adoption throughout North America with tightening demands of overall building performance. Each time this happens, the WWR discussion crops up.
It’s our priority as an industry, of course, that glass and windows continue to win the battle. It’s not just because we make the products—it’s also because, as I’ve written before, glass is a significant contributor to happier, healthier building occupants.
Nowhere is our commitment to meeting changing needs with high-performance glass more apparent than at the annual Building Envelope Contractors (BEC) Conference, which recently wrapped up in early March in Las Vegas. I had the privilege of attending and presenting on a panel discussion at this year’s meeting, and I came away inspired and excited for the work we’re doing and will continue to do.
USGlass provided some great coverage of the event, so I won’t just reiterate what’s already been reported. But I wanted to highlight one major point that came up at the conference, and one that I’ve been thinking about in general lately: how our industry can continue to seek balance and simplicity in the evolving world of commercial construction.
New framing considerations. Successful commercial design and construction mean taking a number of complex inputs (architectural vision, building code, budgets and more) and making them work in harmony with each other. For example, in most commercial window projects, hitting thermal targets must be balanced with meeting the structural demands of the application. How to accomplish this? Projects that have traditionally called for metal framing for its structural benefit fall short when it comes to addressing heat transfer. Since aluminum is highly thermally conductive, a thermal break (strut or pour and debridge) technologies are used to isolate the conditioned space from the outside environment.
That’s not an extraordinarily complex process in itself. But as thermal requirements continue to evolve, getting to that next level with metallic framing is becoming more challenging and complex. Dual pour and debridge, multiple or wider struts foam filling are just some of the options … and that adds complexity and cost.
Alternatively, we are seeing breakthroughs in composite, vinyl or fiberglass framing technologies that can provide the thermal efficiency and structural integrity required. While not yet widely adopted, they offer a simplified, cost-effective solution to the thermal/structural challenge for most commercial punched-opening and window wall applications. Just five years ago, these technologies weren’t taken very seriously in commercial circles. But today, with the help of some basic reinforcement materials, they are getting increased attention as they can help maintain thermal performance, structural integrity and design simplicity where it matters most.
Don’t forget the glass. Warm-edge spacer systems and low-E coatings have helped insulating glass deliver the high performance necessary for today’s thermal demands. But what about tomorrow’s?
In the most demanding code environments in North America, triple-pane insulating glass (IG) has become something of a necessity to hit the required targets. As codes continue to increase in stringency, triples could be creeping further southward before we know it.
Triples, of course, bring with them new complexity for the fabricator and the installer including weight, cost and production efficiency. Technology advancements are being made to compensate, but in our present state, we can address the thermal requirements by simply looking at a balanced design approach with high performance framing materials, coating technologies and true warm edge spacers.
Greater simplicity in commercial glass and glazing benefits everyone. Manufacturers can avoid overly complex IG and framing fabrication. Glaziers can be confident in the installation process. Builders can hit their targets without breaking the budget, providing comfortable, efficient spaces for occupants everywhere.
Joe Erb is commercial sales specialist for Quanex Building Products.