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
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.