Viracon is the largest commercial window glass fabricator in the United States. So it’s not surprising that the company providing glazing for the Kendeda Building for Innovative Sustainable Design has an exhaustive lineup of eco-friendly options.

And the glass for the Kendeda Building is about as high-performance as you can get when it comes to energy efficiency:

• • The Viracon units are tripled-glazed (code only requires two panes).
    

• • Both half-inch spaces between the three quarter-inch panes are filled with argon gas (argon has greater insulating qualities than air).
    

• The outer surface and the middle pane’s room-side surface are treated with a low-emissivity, or Low E, metallic coating (the outer coating is designed to reduce solar heat gain during hot weather, while the room-side coating helps with insulation during cold weather).

• And the Kawneer 1600UT System curtain wall into which the glazing if inserted is among the most thermally efficient framing systems available.

As a result, the glass’ U-factor (a measure of thermal performance in windows similar to R values for insulation) is as low as .13 while its solar heat gain coefficient is .23. Those are very low (meaning: good) numbers.

There’s one other thing that’s special about the Kendeda Building glass units supplied by Viracon: Some hundreds of millions of birds are believed to die in the United States alone after colliding with windows — an emerging issue that the building industry is only beginning to grapple with. The Kendeda Building is one of the first in the Southeast to grapple with that issue during the construction phase. We write about the building’s bird-safe glass here.

Product basics: Viracon Triple-Insulating glass

Manufacturer: Minneapolis-based Viracon is the largest glass fabricator for commercial buildings in the United States. The company has plants in Georgia, Minnesota, Utah and Brazil. It’s a subsidiary of privately held Apogee Enterprises.

Kendeda Building subcontractor: Crowncorr

Products used on Kendeda Building: Clear triple-paned, quarter-inch glass units with half-inch spaces filled with argon. Approximately one third of the units include “simulated sandblast” silkscreen coating for bird safety.

Performance: The glass units are rated at a U-factor of .13 and and a solar heat gain coefficient of .23.

Material transparency and toxicity: Glass is a non-toxic and relatively inert material. The insulated units are sealed with polyisobutylene and solicone, both of which are relatively benign polymers.

Corporate sustainability and responsibility: Parent company Apogee Enterprises ranks higher than 42 percent of global companies on a variety of sustainability and responsibility metrics — slightly lower than the industry average for “Construction Materials” according to CSRHub.

PHOTO AT TOP: Workers for CrownCorr install Viracon glass units into a storefront system on the Kendeda Building for Innovative Sustainable Design. Photo by Ken Edelstein.