NFRC Members Continued Discussions in Minneapolis

The National Fenestration Ratings Council (NFRC) summer membership meeting continued yesterday with a meeting of the technical committee.

Under the U-factor subcommittee, a negative ballot came up on NFRC 100 addressing between-glass shading systems. Larry Livermore, of the American Architect Manufacturers Association (AAMA), questioned as arbitrary the use of 1.75 inches as the indicator of whether or not to simulate the system. A second negative from Steve Johnson, of Anderson Corp., asked why there would be no simulation for systems smaller than that number since simulation is required for grilles between the glass. A motion was passed to change the language to have everything simulated and to move this to the technical committee with the goal of exploring the science behind the number.

The annual energy performance (AEP) subcommittee first reviewed the proposed calculation reports for finding the AEP of a default home or a user specific home. The new draft of NFRC 901 "guidelines to estimate fenestration AEP in single-family residences" uses a range of value to show the AEP of the default home. Some members were concerned that a range of variables wide enough to cover all possible lifestyles would, in fact, offer too wide a spread to be valuable. Use of a single number with an error bar was proposed. A vote of the membership supported continuing with the range for the default house.

It was also questioned whether to lift only energy consumption or also energy costs in the AEP. After voting on options, subcommittee members voted to allow the homeowner to input energy costs into user specific homes.

Finally, members also voted to keep an option that allows for homeowners to find the AEP for existing buildings rather than new construction alone.

Next the software summary subcommittee heard a motion from Margaret Webb, with the Insulating Glass Manufacturers Alliance (IGMA), requesting the component modeling approach (CMA) software request for proposal (RFP) be reviewed and tightened by a professional software writer before the RFP is sent to the board. The decision was supported by the subcommittee and later by the technical committee.

The CMA ratings subcommittee met next.

As Gary Curtis, of Westwall Group, summarized "the board has agreed it would be reasonable to have component level testing." He added that in such a case, whole product testing would not be needed.

Marles McDonald of Quality Testing Inc. addressed the concern of the CMA work. Notably, McDonald said he felt companies involved in custom projects are "having difficulty with the CMA procedure."

Rich Biscoe with Architectural Testing Inc. suggested to the technical committee that a task group be formed to examine "tweaking" the site-built rating system currently in use to suit non-residential buildings. The subcommittee voted to approve the motion, forming a task group to address this issue.

Finally, the ratings committee opened its discussion. The CMA subcommittee heard from Thomas Culp of Birch Point Consulting LLC on a new flow chart delineating two paths for component approval. The first path followed the "traditional method," in which the frame is simulated and some amount of testing would be done for validation. The second path that was suggested for manufacturers of custom products or small manufacturers who don't want to go through the rigor of the first path, Culp explained. With this path, no simulation would be done. Instead, a cross-sectional diagram would be presented, the component would be put into a given category and a worst-case value would be assigned to it. The next chart showed the two paths of a specifying authority leading ultimately toward review by an approved calculation entity, label certificates and IA (Independent Certification and Inspection Agencies) review.

Ultimately the committee voted to return the flow chart to the task group to flush out the language. Numerous additional negatives and comments were debated, although many were recommended back to the task group for its review.

Among those comments were questions about validation testing and the possibility of renaming the approved calculation entity as the accredited calculation entity.

To learn more, see the September issue of USGlass magazine.

The meaning concludes today with the open board of directors meeting.


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