IGMA held a joint meeting with GANA's insulating division to discuss technical matters Wednesday.
IGMA held a joint meeting with GANA’s insulating division to discuss technical matters Wednesday.

The Insulating Glass Manufacturers Alliance (IGMA) held a technical services committee meeting Wednesday during its winter conference in Indian Wells, Calif. The meeting was held in conjunction with the Glass Association of North America’s (GANA) insulating division.

IGMA and GANA have formed a joint committee to address load resistance and dead load support for insulating glass units with unsupported edge conditions, something committee member Tracy Rogers said will be a “long process.”

“We’re looking for any information you can provide on how people are designing for two-sided structural support,” he said.

Another IGMA task group is developing guidelines and establishing tolerances for IGU cavity width. The group was separated into three subgroups–tolerances, thermal performance and solar reflectance.

The first two topics are being addressed in documents, and solar reflectance will be tackled via a webpage on the IGMA website.

Rogers, leading the latter effort, said the website would be targeted to the general consumer, who could gain an understanding of why solar reflectance happens. GANA, meanwhile, continues to work on a Glass Informational Bulletin (GIB) document to explain the science behind solar reflectance.

The webpage approach is being taken with a joint task group between IGMA and AAMA on visual quality, as well. A document is being written on the topic and will eventually be turned into a website to provide information at a consumer level on how to inspect glass.

IGMA also joined with AAMA on other subjects, including edge pressure of insulating glass units. The group aims to develop installation considerations and guidelines for achieving water and air tightness while not over-compressing the edge seal.

Committee member Helen Sanders said this group has been split into sub-groups—one focused on designing a test system and another on how edge pressure can be measured.

“One of the symptoms of too much edge pressure is you get this extrusion of PIB (Polyisobutylene) into the vision area,” she said. “… It’s less of an aesthetic issue and more of a long-term durability issue that we’re trying to understand. … Pressure issues cannot only cause durability problems. In the short term, it can also cause glass breakage.”

Meanwhile, the dimensional tolerances group is revising, updating and adding multiple cavity insulating glass units dimensional tolerances to its document for both residential and commercial insulating glass units. A third ballot will be issued later this month.

Another group will review generic design alternatives for providing gas content units intended for installation in different elevations. It will determine the conditions that impact cavity pressure, including altitude changes. Work on this group, however, is being deferred until the dimensional tolerances task group has completed its work and the bulletin is published.

IGMA wrapped up the conference Thursday following its Emerging Technology & Innovation Committee meeting.