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USGNN Original StoryNFRC Members Discuss Optical Properties During Summer Meeting

Subcommittees of the Research and Technology Committee met this morning as part of day two of the National Fenestration and Rating Council's (NFRC) summer meeting. The Optical Properties subcommittee, chaired by Sheila Gore of Enermodal Engineering, was one of those groups. Members discussed a number of ballots for revising NFRC 300/301 and NFRC 302/303/304 as part of the 2009 document cycle.

Mike Thoman with ATI chairs the NFRC's air leakage subcommittee meeting during Tuesday afternoon's technical committee block.

Regarding the NFRC 300 ballot, some subcommittee members expressed concerns about substitution of the glazing data set currently being used as there are some differences between the way that American International standards detail requirements compared to those of the International Standards Organization (ISO). There was discussion about moving to the international procedure, which would result in slightly different optical and thermal product performance that manufacturers and fabricators publish for their glass product constructions. According to Greg Carney, technical director for the Glass Association of North America, such a major change for the industry that would require considerable discussion with the manufacturers and fabricators to debate the merits and consider the ramifications.

There was also a brief discussion regarding a reference to diffused products (such as patterned glass) in the 301 document.

"Diffusing products are important to this organization and we need some way to evaluate [them], especially as NFRC moves toward commercial buildings," said Mike Rubin with the Lawrence Berkeley National Laboratory. "It's something we need to pay attention to … they are a bit difficult to categorize … but are an important issue."

The documents will return to task group for further review and re-balloting.

Meetings are continuing this afternoon through Thursday with the technical committee block, including the air leakage and U-factor subcommittees. Stay tuned to USGNN.com™ for further updates.

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