Security glazing, energy efficiency focus of PGC presentations

Sahely Mukerji
November 12, 2008
COMMERCIAL, FABRICATION

About 70 attendees listened to speakers on the second day of the Protective Glazing Council International Annual Symposium, Nov. 12, at the Hyatt Regency Crystal City, Arlington, Va.

Quincy Alexander, Applied Research Associates, Albuquerque, N.M., talked about Comparison of Blast Criteria for Glazed Window and Curtain Wall Systems. “In one report, an unidentified Al Qaida operative notes that a building ‘is almost completely made to resemble a glass house, which could be devastating in an emergency scenario ... when shattered, each piece of glass becomes a potential flying piece of cutthroat shrapnel.’ Another excerpt calculates that a particular building has precisely 67,000 square feet of glass, adding for emphasis that it amounts to ‘an acre and a half of glass,’ ” he said.

Alexander compared the United Facilities Criteria Design Criteria and the Interagency Security Committee Design Criteria for glazed window and curtain wall system, determined the required threat and level of protection, and showed an example analysis based on both criteria and compared the results.

Regarding the green theme, “the USGBC [U.S. Green Building Council] expects 10 percent of new construction to be green by 2010,” Alexander said. “And the new president-elect wants 60 percent of new buildings to be carbon neutral by 2030.”

Julia Schimmelpenningh, architectural technical manager, Saflex, Solutia Inc., St. Louis, discussed acoustic design with laminated glass. She reviewed the basics of acoustics as associated with glass and the effects of noise on everyday life; discussed the applicable test and rating standards and laminated glazing products in noise damping. “Acoustical specifications are increasing, and there are more residential and commercial applications in the form of double and triple laminated glazing units,” she said. “But building code doesn’t mandate acoustical performance. FAA [Federal Aviation Administration] has requirements around airports and NHTSA [National Highway Traffic Safety Administration] influence adjacent highways.” ASTM has three test standards: E 90 (test method), E 413 (Sound Transmission Class calculations) and E 1332 (Outdoor-Indoor Transmission Class calculations), she said.

In glazing design, three basic features influence sound transmission loss, Schimmelpenningh said: glass thickness and stiffness, insulating glass air space thickness and interlayer damping.

“Acoustical interlayer delivers high-performance damping with lower weight configurations,” Schimmelpenningh said. “Laminates offer flexibility in design variables and can be used to create acoustically comfortable architectural settings.”

Charles Eva, research student, University of California San Diego, presented test results on protective glazing in seismic events. His team at the university tested 53 specimens. “Preliminary results indicate application of laminate improves seismic performance of glazing units, however, anchored laminate creates local stress concentrations and may exasperate the damage,” he said.

Larry Livermore, senior project manager and business development manager, Architectural Testing Inc., York, Pa., talked about Specifying and Testing Windows for Blast, Impact, Thermal and Acoustical Performance – Avoiding the Pitfalls. He provided an overview of four performance attributes--blast, impact, thermal and acoustical—pertaining to fenestration products and reviewed specifications and test methods, such as General Services Administration, Interagency Security Committee and AAMA 510 standards for blast; International Building Code and Florida Building Code for hurricane; AAMA and NFRC standards for thermal; and AAMA and ASTM standards for acoustical. “Typical performance issues are errors and omissions, or ‘the oops factor’: value engineering or effect of value; design changes in another part of the building [that] can change the product performance; 'get-er-done' workmanship; 'not my problem' attitude; and field repairs that make the product worse than original,” he said.

To resolve those issues, “have a design review; communicate; consult with experts; perform field inspections and quality control so products are installed according to standards and specs; test for quality control; and inspect and field test,” he said.

Steve Lewis, Technical Glass Products, Snoqualmie, Wash., presented Fire Rated Glass for Energy Efficiency and Protective Glazing. He discussed fire-rated glazing technologies, such as specially tempered glass, clear ceramics and glass firewalls. Specially tempered glass has a 20-minute rating and doesn’t meet hose stream test. Clear ceramics can withstand a lot of heat, have 60-minute and 90-minute-to-three-hour ratings and zero thermal expansion rate. Glass firewalls are a highly specialized product, such as Pilkington Pyrostop that has several layers of glass with special interlayers and a two-hour rating, he said. Block Museum of Art in Chicago uses Pilkington Pyrostop, and the Olympic torch was made of clear ceramics, he said. Wired glass also is evolving, like laminated wired glass, such as Pyroshield Plus. Asahi still makes wired glass.

Steven Stonehouse, director of marketing, Norment Security Group Inc., Montgomery, Ala., presented Detention Glazing in Today’s Society. He discussed the ASTM F-33 Standards and their applications to security glazing, mistakes typically made with security glazing and how to avoid them. He also talked about products typically used for detention facilities. “You need to be able to select the right product for the specific threats and minimize the improper product purchased by the contractor or owner,” he said. “Seek assistance if not sure of proper product. Liability, protection of life and assets are at stake.”