U-factor Subcommittee Addresses Four Ballots, Creates New Task Group to Study Gap Widths

Thoman leads U-factor Subcommittee Discussions

U-factor Subcommittee Chair, Mike Thoman, addressed four ballots during this afternoon’s meeting.

NFRC 100 Commercial Skylights Ballot

This ballot concerned adding language to the NFRC 100 to accommodate the rating of large, commercial skylights. A motion to approve the ballot, noting that the relevant TI would be rescinded, and forward it Technical was approved by unanimous voice vote.

NFRC 100 Skylight Appendix 3 Ballot

The new Appendix A 3 addresses an emerging need by specifiers for project-specific skylight U-factor ratings similar to those available for non-standard window sizes as described in A.2.

The fundamental issue here is that as building codes continue to reduce the maximum allowed U-factors for all fenestration products, it is important to all for non-certified ratings to be made available for skylights at actual installed slopes.

One concern was that a statement in the document regarding certification should not be included in a technical document because NFRC does not allow for the certification of non-standard conditions.

After striking the word “certified” from the language and confirming that standard skylight sizes are simulated, a motion to move the ballot forward passed by unanimous voice vote.

NFRC 100 Sash Kit Ballot

During the Summer 2010 Virtual Committee Meeting, a ballot to revise the language in the NFRC 100, Section 5.1.2 Variations from Standard Product Lines regarding sash kits of any operator type.

While this ballot failed, a task group was assigned to revisit the issue. After creating some modified language, the group decided it would be more applicable to all products by moving it to the NFRC 100, Section 4.2.7 General Rating Rule, thereby removing Section 5.1.2. This change will cover operator types such as window sash kits, sliding door panels, and side hinged door slabs.

One negative was that sash kits, sliding door panels, and side hinged door slabs that are identical in material and design as a manufacturer’s rated product line may use the same ratings. A motion to move this ballot forward to Technical was passed by unanimous voice vote.

NFRC 102 Glazing Deflection Ballot

This ballot seeks to add language to the NFRC 102 test procedure regarding the measurement of glazing deflection.

In the course of discussing how various gap widths would apply to various IG units, one member expressed concern that the numbers were arbitrary rather than founded in science. This resulted in a move to table the ballot until further studies can be conducted on the gap width. Chair Mike Thoman created a task group to take on this work.