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Performance Grade is a numeric designator that defines a specific set of NAFS-specified product performance requirements for a specific Design Pressure (DP) range as required by conditions at the intended location of the building. A product achieves a Performance Grade rating only upon successful completion of all applicable tests–primarily those for structural performance under wind loading and for resistance to water penetration and air leakage.
Changes in the 2008 version of NAFS realigned and reduced the total number of the Performance Class designations as defined by the Performance Grade (a set of performance requirements corresponding to a Design Pressure range) at the intended location of the building. This simplifies the specifier’s task in matching fenestration performance to project requirements and consolidates testing requirements for manufacturers.
In the 1997, 2002 and 2005 editions, there were five Performance Classes - R, LC, C, HC and AW. For the 2008, the C and HC performance classifications were eliminated and replaced with a singular CW classification. There have been no further changes to the performance classifications since 2008, which are currently defined as:
For more information, visit the Performance Class Overview web page.
Changes from the 2011 to the 2017 versions of NAFS added operator types including the Folding Door (FLD) System, Limited Water Folding Door (LWFLD), Top Turn Reversible (TTR) and Tropical Awning Window Secondary Storm Product (TASSP). Also added was the ability to label a door system as tested without hardware by adding an “X” to the door designation.
The five newly added operator types are: