The Cat’s Out of the Bag: ASTM Completes Update to IG Standards

By Jeff Haberer

Wikipedia defines the concept of herding cats as “An idiom denoting a futile attempt to control or organize a class of entities which are inherently uncontrollable.” While I can’t say that ASTM members are completely uncontrollable, leading a task group often feels like herding cats.

The task group which governs the three insulating glass (IG) standards is E06.22.05. The membership roster has more than 40 cats, uh … I mean, members. And each cat/member has his or her own needs, opinions and directions that they want it to go.

The task group reports to a subcommittee and then to a main committee. There’s about 735 who can vote on new and revised E06 standards.

Here’s a quick summary of each standard and a quick look at the general areas that have changed.

E2188 Standard Test Method for Insulating Glass Unit Performance

This test method involves accelerating the environmental effects on insulating glass units. It employs two test chambers. One provides an environment of constant humidity at an elevated temperature of 140°F. The other chamber cycles test specimens from hot (140°F) to cold (-20°F), with phases of added moisture and UV radiation. The test evaluates the ability of the IG seals to resist the passage of moisture. Major changes include:

• Allowing multiple methods of moisture introduction to the chamber;
• Tighter output range on the UV lamp;
• Allowing multiple UV meters to measure UV output;
• Corrections to weathering chamber dimensions;
• Measurement of time in the chamber will be by number of cycles instead of days; and
• Clarification of frost point measurement timing.

E2189 Standard Test Method for Testing Resistance to Fogging in Insulating Glass Units

This test is used to determine if anything inside the IG unit can volatize and cause a chemical fog. Two IG specimens are placed in a box heated to a uniform temperature of 120°F. Cold plates, chilled to a constant 70°F, are positioned on the surface of each specimen. The test runs for seven days, after which specimens are removed from the chamber and visually inspected for chemical fog. The major changes include:

• Tighter specification on lamp location relative to the test specimens;
• A clearer requirement that the applied voltage shall be 230 VAC;
• Allowing multiple UV meters to measure UV output;
• Layout locations for muntin bars in test samples;
• Address other internal components in addition to muntins (art glass, blinds, etc.); and
• Proportion internal components to the small test specimen size.

E2190 Standard Specification for Insulating Glass Unit Performance and Evaluation

This standard sets requirements for performance of specimens in the above two test methods and essentially couples testing together. It also sets requirements for the evaluation of Argon retention before and after weathering. The major changes include:

• A base set of samples, with no internal components, must
pass both E2188 and E2190;
• Internal components will only be required to pass E2189 (fog);
• Failure of internal component samples will not fail the base set; and
• The average Argon concentration of two cavities in a triple shall be at least 50 percent.

In the past, a set of 12-14 specimens had to have six units pass the E2188 weathering phases, and two units pass E2189 fog testing. If there was a failure in either test, the entire set failed. A new set must be submitted and tested again to both E2188 and E2189.

Probably the biggest change to the IG standards is the concept of a base set of samples, as noted above. Along with this is the de-coupling of internal components from this base set. This change will allow manufacturers to test more different types of internal components without having to endure the long weather phases of E2188. Getting a sample set through this testing typically takes anywhere from four to six months. That’s a long time if you’ve lost certification and can’t sell units until you retest and pass.

I’m happy to finally declare that all three standards have passed balloting successfully and will be published by ASTM this spring. The task group took a break the first week of April but plans more improvements and will continue herding the cats at ASTM.

Jeff Haberer is the director of technical services for Trulite Glass & Aluminum Solutions and chairs the ASTM task group E06.22.05 for insulating glass durability.

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