FGIA Analysis May/June 2022May 20th, 2022 by Nathan Hobbs
Sizing Up: Updated Standards Keep Hardware On Pace with Product Evolution
By Glenn Ferris
One growing trend of recent note, especially in appropriate climates, includes the integration of indoor and outdoor spaces using large arrays of multi-panel glass doors. For the first time, these large-format doors were recognized as a separate market segment in the FGIA 2019/2020 U.S. Industry Market Studies. The study pegged the total annual market for such products at 175,000 units.
As with all fenestration products, these assemblies must be tested, rated and certified to meet requirements for air infiltration and water penetration resistance, as well as structural integrity under windloading performance attributes (AWS). Procedures have been developed for qualifying multi-panel sliding doors based on extrapolating results from tests for individual panels and applying to a multi-panel system, rather than separately testing the full assembly, thereby reducing testing expenses.
However, the overall performance capability goes well beyond that of the framed glass sash to encompass numerous components—items that are often not readily visible but are critical in the product’s ability to perform over a long service life. One category of these relatively unsung, but nevertheless critical, components is operating hardware, including sash balances, multi-bar hinges, swing door hinges, rotary operators, and roller assemblies. FGIA publishes AAMA hardware standards that cover these basic components.
As products evolve, the challenge is maintaining adequate test methods that simulate enhanced real-life usage conditions. In general, the bar keeps getting raised over time as materials and technology improve and the marketplace ratchets up demands.
For example, older style sliding glass doors (SGD) were typically operated by sliding the bottom gasket of the door panel along its track. As door size and weight increased, high-performance roller assemblies were introduced, including newer styles that enable the operation of top-hung “lift-slide” panels.
To address today’s increasing use of heavier multipanel sliding doors, AAMA 906-21, Specification for Sliding Door and Lift and Slide Roller Assemblies, was recently updated from its 2018 edition. The specification describes the means to evaluate a roller’s ability to qualify for the weight rating sought by the manufacturer through testing of representative samples. This involves cycling the rollers under load for 10,000 full-open/full-close cycles without the roller “jumping” its track or causing the door sash to become more difficult to operate.
In the current version, the specified maximum force to initiate the sliding motion for different weight ratings of the roller assembly has been expanded to address the advent of heavy-duty rollers to support multi-panel doors. Presented in table form, the weight ratings and associated maximum operating force have expanded from the previous two rating categories (75 and 100 lbs.) to five groupings ranging from 75 to over 600 lbs. By comparison, a typical 80-inch by 36-inch SGD panel using insulating glass weighs about 50-75 lbs.
Also recently updated is AAMA 904-21, Specification for Multi-Bar Hinges in Window Applications. A multi-bar hinge, composed of four or more bars, supports a variety of sash types that operate beyond the plane of the wall, such as project-out (at bottom), project-in (at top), casement (out-swinging or in-swinging), and parallel opening (all four sides of the sash opening outward) types. Under AAMA 904-21, two pairs of randomly chosen samples of a specific multi-bar hinge design are tested and are given a maximum rating for weight, height, and/or width, depending on window type. The testing confirms lack of damage or deformation after 8,000 open and close cycles, at the rate of 4 ± 1 cycles per minute. The format of the resulting rating code for product designation is provided.
Glenn Ferris is fenestration standards specialist for the Fenestration and Glazing Industry Alliance (FGIA).
To view the laid-in version of this article in our digital edition, CLICK HERE.