 
NFRC Subcommittee Members Vote Against Proposed
Research Projects
June 19, 2012
by Tara Taffera, ttaffera@glass.com
The National Fenestration Rating Council (NFRC) held a special virtual
meeting of the Research Subcommittee yesterday and one of the main
agenda items was deciding whether the NFRC should proceed with two
proposed research projects. Ultimately, members voted no to both
proposals so they will not move to the request for proposal (RFP)
stage for the fall meeting.
The first ballot, "Develop Artificial Daylighting Source for
Solar Calorimeter Testing," was proposed by Bipin Shah, WinBuild
Inc., and Dr. Ross McCluney, Sunpine Consulting.
The background information in the ballot pointed out that NFRC calls
for the use of an outdoor solar calorimeter for solar heat gain
coefficient (SHGC) measurements, which tracks the sun at normal
incidence. While it uses an actual solar spectrum, this testing
procedure has inherent problems of maintaining a controlled environment
and limits the use of equipment to only during clear sky and moderate
wind conditions. These outdoor environmental limitations in different
location and climate zones restrict the use of the solar calorimeter
especially in regions where there is significant cloud cover and
windy climates.
Several countries currently are looking into developing Solar Calorimeter
testing procedures and facilities, according to the proposal. These
countries are strongly considering the use of indoor testing facilities,
currently the predominant approach in European countries. Thus,
research was proposed to investigate the availability and/or development
of a solar simulating electrical source having both good solar spectral
range coverage and a reasonably acceptable spatial and directional
distribution of the flux on a target large enough to include most
fenestration systems that could be tested with this approach.
Benefits cited by its proponents included: Improved testing methodology
with reduced discrepancies in solar calorimeter testing results
that will better meet the NFRC's mission of fair, accurate and credible
ratings and will help increased international harmonization.
One member in attendance said it was too early for the ballot to
be going forward while another agreed that it "is slightly
premature."
While the motion to proceed with the research failed, committee
members indicated they may modify the ballot and bring it back at
a later date.
The estimated cost of the project was $100,000 to $125,000 and the
proposal estimated it would have taken approximately ten months
to complete.
The second ballot, "Testing and Calibration of a CTS Panel
with a Roomside Surface low-E Coating," was proposed by the
NFRC's Testing Laboratory Task Group.
Background information provided in the ballot pointed out that fenestration
products have become more popular with the placement of low-E coatings
on the interior-most surface to help lower U-factors. As part of
the NFRC certification process, testing laboratories are to validate
the simulations by conducting an NFRC 102 thermal performance test
to determine the U-factor. Therefore, if a fenestration manufacturer
was to submit a test specimen that had a low-E coating on the inner-most
surface (for example: on surface #4 of a dual-glazed IG system),
it is highly likely it would not validate because the accuracy of
the testing being conducted does not take into account the reflective/absorptive
abilities of the low-E coating, according to the proposal.
NFRC conducts an Interlaboratory Comparison (ILC) every year to
ascertain the uniformity of each of the NFRC accredited thermal
testing laboratories by testing a single test specimen, according
to the ballot. The 2010 Thermal Test ILC determined that there was
an issue with the calculation of the standardized U-factor of this
product, per ASTM C1199 and NFRC 102. None of the laboratories were
able to validate the product against the simulated U-factor by using
the current calibration procedures.
Current calibration procedures require the use of a Calibration
Transfer Standard (CTS) to determine the chamber's interior and
exterior film coefficients (basically, adjustment of the proper
interior and exterior wind velocities). This CTS is required to
have clear glazing (glass or plastic) on both sides of a calibrated
foam material (typically EPS or expanded polystyrene), according
to the proposal.
Because the CTS has clear glass surfaces, it is undetermined if
the chambers are in fact calibrated to test fenestration products
with exposed low-E coatings.
The research was proposed to investigate whether thermal chambers
are required to be calibrated with CTSs including a low-E coating
on the inner-most surface before testing and validating any fenestration
product with low emissivity exposures.
The benefits cited in the proposal included: Improved testing methodology
with accurate U-factors for products physically tested for the Independent
Verification Program, test-only or validation for initial or re-certification
per the NFRC 700 program.
"I wonder if this is worth the investment," said Thomas
Culp, owner of Birch Point Consulting LLC. "I am not sure we
need to do it. In my view it is already done."
Another member pointed out that the objective of the research is
to harmonize international standards but the international players
aren't involved in this.
"So it's a valuable effort but this isn't the right approach
as it seems like we want to come up with something, then just have
others adopt it and that's not the right approach," he said.
The estimated cost of the project was $25,000 to 35,000 and would
have taken approximately six months.
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