The Optical Properties Subcommittee convened from 9:00 - 10:00 a.m. During the meeting, the Optical Spectral Data Task Group proposed significant changes in the NFRC 302 to better ensure that accurate optical spectral data are included in the International Glazing Database (IGD).
A number of issues came up during the meeting.
1. Tom Culp, from Birchpoint Consulting, presented a negative. He said he believes a lot of unnecessary details about the review process and appeals process are being deleted. Culp also said people commonly complain about chasing the third decimal point in the U-factor.
2. Steve Farrar, of Guardian, said the proposed ballot provides no analysis of the need for changing the established procedure, whereby glass manufacturers are responsible for providing spectroradiometric data for the IGD. Farrar also said the ballot provides no assessment of the cost of the proposed procedure and the associated impact on the new product commercialization. Furthermore, Farrar said the proposal provides no basis for the recommended four-fold tightening in the tolerance for emittance. Farrar believes the tolerance should be related to its impact on actual product ratings, not to the precision of modern testing equipment. Finally, Farrar said any change in measurement tolerance must be consistent with the instrument manufacturer’s statement of capability for the intended measurement.
3. Joe Hayden, of Pella Corporation, and Chairman of NFRC’s Board of Directors (BOD) said that section 3.3 makes reference to a list of approved labs in an “Appendix TBD.” This appendix, however, does not exist in the ballot’s draft. Hayden said this needs to be corrected before final publication.
4. Steve Johnson, of Andersen, said there is a need for greater clarity around emittance limits and how compliance to those emmitance limits will be demonstrated.
The meeting concluded with Jim Larsen asking the crowd if anyone wanted to work with him study the comments and work on resolving them. Seven attendees volunteered. They include the following: