Success in the Balance: Form and function with balanced doors When choosing a marquee entry door system, specifiers need to consider several criteria including traffic, the building’s wind and stack action pressure, accessibility, and obstructing pedestrian traffic. Balanced doors can address these criteria with fluid opening and closing, even when strong external wind pressures and internal stack pressures. Design, frame, and tempered glass options are also discussed. |
Overlooked Considerations for Windows and Curtain Walls The primary factors most designers consider when selecting window and curtain wall systems for their projects tend to involve cost, appearance, and energy efficiency. However, other considerations—such as weatherproofing, performance, and durability—can also be critical. Understanding material options, along with aspects like performance data and perimeter detailing are crucial. |
Testing Glazing in the Field: Performance ClassesUp until the 2008 edition of American Architectural Manufacturers Association/Window and Door Manufacturers Association/Canadian Standards Association (AAMA/WDMA/CSA) 101/I.S.2/A440, North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS), there were five performances classes of windows with differing requirements for test pressures, allowed leakage rates, and other variables. This sidebar discusses the current four types, and their minimum performance grades. |
Testing Glazing in the Field: Specifying procedures now avoids trouble later Laboratory testing of fenestration products to the North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS) verifies the performance of a specimen of the fenestration product itself. How can one be certain the specified performance will be realized after installation? When properly applied, field testing can be a useful way to verify actual installed performance during construction and prior to occupancy of a building. The key is testing in conditions that accurately simulate the real-world environment and ensuring that the appropriate test method is applied to the specific installation. |
Seeing Through Glass Cracks
FAILURES |
An Advanced Frame of Mind: The Window-to-wall Ratio Dilemma In 2013, the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) proposed an addendum to ASHRAE 189.1, Standard for the Design of High-performance Green Buildings. The proposal seeks to reduce the window-to-wall ratio (WWR) area from 40 to 30 percent in small and medium-sized prescriptive-path buildings (buildings fewer than 23,226 m2 [250,000 sf]). ASHRAE 189.1 would allow building and design professionals using the performance-based approach to increase the glazed area. |
