IGMA meeting opens with discussions on triple glazing, thermal stress, gas permeability

The Insulating Glass Manufacturers Alliance, Ottawa, ON, kicked off its Annual Conference March 22 at the Paris Hotel, Las Vegas. The meeting runs through March 25 and is held in conjunction with the Topeka, Kan.-based Glass Association of North America's Glass Week and BEC Conference.

The IGMA event began with a board of directors meeting on March 22, followed by working group meetings on March 23. The Glazing Guidelines Working Group focused their discussion on two items: revisions to TM-3000-90(04), the section of the North American Glazing Guidelines for IGUs that addresses setting blocks, and the development of capillary tube guidelines, from a joint IGMA and GANA working group. In regard to TM-3000-90(04), the group discussed glazing clearance and setting block height for residential insulating glass, and the development of a technical bulletin on the importance of setting blocks for residential windows.

The Gas Permeability Working Group discussed progress on Phase 2 of the Gas Permeability Research Project that addresses sustainability of IGUs through the development of a test protocol for argon permeability. Phase 2 of the project addresses the influence of the geometry of the IG spacer, spacer composition and the effects of the adhesion of the sealant to the respective spacer surfaces.

The Thermal Stress Working Group had two items on the agenda: the ASTM E 2431 Thermal Stress Standard, a standard that determines the resistance of glass to thermal loads, and the Thermal Stress Bulletin that identifies and addresses the conditions of thermal stress in IGUs. The group, specifically, debated thermal stress in the center lite of triple glazing.

Triple glazing conversation continued during the Design Considerations for Multiple Cavity IGUs meeting. The group is working to develop a document of design considerations for such IGUs. Considerations include thermal stress, gas content, wind load, stresses on seal system, coatings, fabrication techniques, altitude limits, glazing, non-structural intermediate layers, glass thickness, structural applications, exterior condensation and optical.