Proposed Elimination of NAFS Gateway Minimum Test Sizes for Classes R and LC
April 26, 2017
In November of 2015, the joint NAFS Strategy Task Force convened and created a Purpose and Mission for the future of NAFS, which was approved by the governing bodies of all three sponsoring organizations (AAMA, CSA, WDMA). The fundamental result is a directive to the JDMG to simplify NAFS going forward.As part of this simplification effort, one of the JDMG’s more prevalent proposals is to eliminate Gateway Minimum Test Sizes (GMTS) for Class R and LC products. This proposal is a result ofextensive discussions both within and outside the JDMG, and is based on the following rationale:
1)Test sizes will be driven by market forces.Ultimately, it is our end customers who dictate the desired features and characteristics of products that are successful in the market place. This includes the range of product sizes that manufacturers offer. NAFS needs to recognize this and allow manufacturers to determine their own test sizes that match the needs of the markets in which they desire to participate. Specifying an arbitrary GMTS is not consistent with a market driven economy.
2)Any products larger than the maximum size tested (MST) will not be qualified.It has been a long-standing basic principle of NAFS and its predecessors that manufacturers must test the largest size (both width and height) for which qualification is desired, and that any products either wider or taller than the MST are not qualified. This principle will be maintained and, if necessary, further emphasized.
3)GMTS represents an extra burden that adds no meaningful value.In cases where the GMTS exceeds the largest standard size offered by a given manufacturer, that manufacturer is forced to use non-standard methods to fabricate the necessary test samples. This places an extra burden on the manufacturer and results in test samples that are likely not truly representative of the manufacturer’s intended design. As such, this adds cost and complexity that represents no meaningful value for our end customers. Allowing manufacturers to test and qualify only the maximum size(s) they market will save the cost of unnecessary testing of sizes they do not intend to offer.
4)GMTS does not prevent inaccurate performance claims. One argument often presented in support of maintaining GMTS is that it will prevent manufacturers from testing a smaller size to achieve an inflated performance rating, and then incorrectly claiming that the achieved performance rating applies to sizes larger than MST. The JDMG disagrees with this argument. NAFS has always provided an option to test sizes smaller than MST after all the GMTS requirements have been satisfied. As such, a manufacturer can currently test a GMTS sample to the minimum requirements, and then test a smaller size sample to a higher performance rating. That manufacturer would then be able to misapplythe smaller size test results in the same incorrect manner.Nothing in NAFS-2019 nor any of its predecessors prevents manufacturers from falsely claiming compliance or from claiming compliance to only portions of the standard. Retention or elimination of GMTS does not change this. The JDMG believes this issue is better addressed as indicated by item #2 above.
5)GMTS can inhibit innovation and creativity.GMTS can represent an artificial barrier to the use of innovativematerials, components, profiles, etc.In cases where manufacturers choose a limited size offering, lighter and less costly designs may be fully adequate at those sizes, but fail to perform adequately at GMTS. The lighter designs will self-limit the sizes qualified, and the productswill still have PG-minimum or higher performance as dictated by the manufacturer’s design intent. Such products could qualify using many other “out of the box” ideas.Elimination of GMTS can help improve innovation and creativity, such as the use of components with limited capacity.
6)Elimination of GMTS represents simplification. As stated in the introduction, the fundamental directive from the NAFS Strategy Task Force to the JDMG is to simplify NAFS. Elimination of GMTS is consistent with that directive. In addition to the items above, it will:
a)Eliminate the need for Alternative Minimum Test Sizes.
b)Reduce the need for complex definition of operator types, and for auxiliary component and material criteria specific to those types. Instead, component/material criteria are kept relevant to that component/material, rather than an operator type. For example, rotary hardware need only comply to the hardware criteria, and not to separate GMTS size-criteria based on whether it is a casement, awning, dual-action or jalousie.
c)Facilitate improved US/Canadian harmonization of operating forces, air leakage, and several other primary and secondary performance measures, since these no longer need to be different for different GMTS sizes and operator types.
d)Put greater emphasis on the actual size tested, and eliminate the need for two“connected” test reports (one forGMTS and a second forOptional PG).
e)Eliminate the confusion that “downsized” adds to product designators and labeling.
7)Following are some additional miscellaneous points for consideration:
a)Comparison is often made between products with the same PG rating, but of different Performance Classes. GMTS has been one of the differences between R, LC, CW and AW. Eliminating GMTS only applies to the minimum PG within those classes. Products with PG-above-minimum are based on testing of a specific size unrelated to GMTS, and can only be correctly compared to products of the same or larger tested size.
b)Elimination of GMTS within the same Performance Class and PG neither simplifies nor complicates the comparison of different operator types, because each operator type in NAFS-2017 and its predecessors has a unique GMTS.
c)This proposal only applies to Classes R and LC. The JDMG is proposing to retain GMTS for Classes CW and AW for several reasons. This includes retaining the requirement that AW products also be tested to AAMA 910, which allows AW products to in some cases have a GMTS the same or smaller than the GMTS for CW. GTMS is also being retained for Classes CW and AW because the they are limited to L/175 deflection.
Overall the JDMG views this proposal as a substantial improvement to NAFS. This change, along with the many other proposed changes, will result in a streamlined standard/specification that will be more effective. It will be easier for manufacturers to implement, it will be easier for certification agencies to enforce, and will therefore assist our industry in providing customers with the top-quality and cost-effective products they desire.