To obtain less variation in test results of sliding window and door systems, E 2068, Standard Test Method for Determination of Operating Force of Sliding Windows and Doors, has been developed by ASTM Subcommittee E06.51 on Component Performance of Windows, Curtain Walls, and Doors, under Committee E06 on Performance of Buildings.

According to Rick Curkeet, chairman of the subcommittee task group that developed E 2068, the test method applies to products with opening/closing parts sliding or rolling in one plane, such as:

• Single/double hung windows;
• Horizontal sliding windows; and
• Sliding or rolling-type patio doors.

“The ASTM window and door operating force standard provides a detailed set of procedures for measuring both the forces required to initiate motion of the operating part of the product (a sash or door panel),” said Curkeet, chief engineer, Intertek Testing Services, Warnock Hersey, Middleton, Wis.

“The need for this method was recognized for years as many sliding window and patio door specifications required measurement and reporting of operating forces as a part of a broader performance test program,” he elaborated. “While there was no standard practice, most laboratories developed and used their own methods of making these measurements. However, it became apparent that significant variation in results was likely depending on each laboratory’s interpretation of what data was needed and how the test should be conducted.

“This issue became more critical over time as designs were made tighter in response to the demand for more air-tight, energy efficient construction,” he continued. “The use of more and better weatherstrip in window and door designs tended to increase the force required to open and close the product. In addition, there was recognition that often two distinct operating force measurements were needed to accurately convey how a particular product operated. Some products, for example, require a relatively larger force to disengage the movable sash from a weather-stripped frame pocket and a much lower force to move the sash through the rest of its operating range. Thus the standard includes both ‘breakaway’ and an ‘in-motion’ operating force measurement procedures.”

Curkeet said Test Method E 2068 recognizes well-known methods of force measurements—force-gauge and hand-applied pressure, as well as dead weights, suitable for:

• Laboratory product comparisons, qualifying products, or both to meet window or door operating force specifications; and
• Use in the field to determine the operating forces required to open and close installed sliding windows and doors.

“While the primary motivation for developing this standard was as a tool in determining new product design compliance with industry specifications, it was apparent that it would also have application to installed products in the field,” Curkeet said. “The task group recognized that the operating forces for these products would be substantially affected by the quality of the product installation, product age and maintenance and environmental conditions. This led to the need to include discussion of these factors and reporting requirements that would assure that relevant additional information would be provided to interested parties that would help in making appropriate conclusions regarding field measurements.

“It is expected that many of the current ASTM test methods that apply to fenestration products (under the jurisdiction of Subcommittee E06.51) will include reference to E 2068 in their next revisions,” he concluded.

For further technical information, contact Rick Curkeet, Intertek Testing Services, Warnock Hersey, Middleton, Wis. (phone: 608/836-4400). Committee E06 meets April 1-4 in Phoenix, Ariz. For meeting or membership details, contact Staff Manager Steve Mawn, ASTM (phone: 610/832-9726). //

Copyright 2001, ASTM