Architects Get Crash Course in Glass and Glazing

Class was in session Thursday at the Hyatt Regency Long Island in Hauppauge, N.Y., as a large group of architects gathered for Architects’ Forum™ 2015. The daylong program included five AIA accredited sessions focused on architectural glass and glazing, as well as several networking opportunities.

Technoform’s Laura Woods gives a presentation at Architects’ Forum on thermal break and high performing insulating glass.

Technoform Bautec sales engineer Bill Blazek and Technoform Glass Insulation product manager Laura Woods kicked off the forum with a presentation on thermal break and high performing insulating glass for the fenestration industry. Woods said that because of the importance of the building envelope, “Small tweaks can really impact the overall performance of the building.”

Blazek discussed codes and regulations, noting that 45 states have adopted ASHRAE 90.1 building codes. “We’re seeing a trend toward thermal products,” he said,” which makes sense as energy codes rise.”

Blazek explained the benefits of a polyamide break system, including superior thermal performance, high structural performance, increase longevity and system design flexibility, in addition to it being aesthetically pleasing and containing versatile material properties.

Woods then broke down the warm edge spacer and its benefits, which include improved overall U-value, higher sightline temperatures and improved condensation resistance.

Later in the morning, Leigh Anne Mays, commercial sales manager for Guardian Industries, discussed the glass selection process and the aesthetic options available to meet project design and performance requirements.

She started by explaining the basics of glass manufacturing and float glass types, including low iron glass, which “reduces the greenish color and slightly increases visible light transmission.”

In discussing coatings, Mays spent a lot of time on low-E. “Silver is the ‘workhorse’ of low-E coatings,” she said.

Mays went on to explain that when installed on the number two surface of an insulating glass unit (IGU), the low-E coating will reflect or absorb infrared (IR) heat from the outside, reducing solar gain and cooling costs during the warm months.

When installed on the number three surface of an IG, the low-E coating will reflect IR heat from inside the room to help reduce the energy loss during the cold months, thereby reducing heating costs.

She cautioned, however, because of the complex layers in low-E coatings, not all coatings can be placed on the number three surface. “The film-side color is not always the same and consistent between individual coatings,” she said.

Mays also gave advice on viewing samples, recommending they be viewed outdoor/natural lighting conditions, preferably in a slightly overcast condition, for the most accurate rendering of transmitted and reflected color.

“Also, architects are encouraged to consider angle of observation, interior lighting conditions and potential effects of glare when choosing glazing products,” she said.

“When evaluating samples outdoors, it is recommended viewing them during various time of the day and under varying lighting conditions, e.g., cloudy versus sunny conditions.”

Mike Nicklas, business development manager for J.E. Berkowitz, talked to attendees about glass fabrication and design issues, explaining how to recognize certain values in glass design to make successful specifications and drawings for bid. He also covered considerations for the proper architectural glass choice and upgrading the quality of architectural glass specifications.

“Engage a high quality fabricator early in the process,” he told the architects. “That fabricator is going to know about glass availability, coating availability, etc. and can help in planning and how it relates to your project schedule.”

He said high quality fabricators can help by performing thermal stress analysis and assist in determining design loads, constructability concerns and can provide samples.

He spent time explaining issues that can come up in the heat-treating process, such as roll wave distortion. In order to minimize roll wave distortion, Nicklas recommended designers specify tighter tolerances, thicker glass and directional tempering.

“The thicker the glass, the less likelihood of roll wave distortion,” he said.

David Devenish of Fenzi North America gave an overview of the characteristics insulating glass sealants must provide to ensure long-term thermal performance, structural durability and longevity of insulating glass units.

He discussed the difference between standard units and functional units. Standard units, he explained, are two parallel glass panes—air-filled and separated by spacer filled with desiccant. In a standard unit, two sealants are used to maintain air space seal and hold the glass units together.

Standard units are typically uncoated, and he said, “the market is moving to functional units.” Functional units, he said, are utilized for high-performance and safety glazing applications. They consist of two or three glass panes, gas-filled, and are typically coated.

James Wharton of Technical Glass Products closed out the forum with a presentation on fire-rated glass and framing.

He discussed new trends in fire-rated glazing and what to look for when specifying fire-rated glass.

Wharton detailed what constitutes “fire protective,” noting that a fire protective product stops flames and smoke, is “thin glass,” is made of traditional fire-rated material (wired glass, glass ceramic, hollow metal steel frames, etc.), and that they may not exceed 25 percent of the aggregate length of the wall and may not exceed 120 square feet. He added that products with fire-ratings over 20 minutes must pass the required hose stream test.

Meanwhile, he defined “fire resistive” as able to stop flames, smoke and radiant heat (both glass and frames). He said it consists of “thick” glazing, can be classified as a “wall” rather than an opening (window), and both the glass and frames of the product must block passage of radiant heat.