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May - June 2003

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Argon Gas
The Faith is in the Filling
by Ric Jackson

Until recently, the process of filling insulating glass (IG) units with argon has been subject to faith—faith among manufacturers that IG units have been filled properly and sealed and faith among consumers that something they can’t see is actually in the unit they purchased. Manufacturers have held the benefit of the doubt for many years, but as testing methods improve, the consumer has a heavier arsenal to challenge the industry.

Importance of Fill Levels
The possibilities sound frightening: lawyers test installed windows, recruit consumers and submit a class-action lawsuit against a manufacturer for false claims of argon content in IG units. The best bet to lessen the possibility of these suits is to adhere to proper manufacturing processes—ones that ensure high argon fill rates and high retention rates. 

“I’ve used argon retention as a bellwether of whether a window is a good unit,” said Randi Ernst, president of FDR Design Inc. in Buffalo, Minn. “If an IG unit can’t hold argon, it isn’t going to keep moisture out either.”

Holding argon in, keeping moisture out and maintaining thermal performance all depend upon an impenetrable seal between the glass or coating surface and a flexible warm-edge spacer. 

When coupled with proper manufacturing processes, warm-edge spacers form a durable seal to trap argon in an IG unit. This reduces the chance of premature window failure and even unit deflection that can occur if gas escapes rapidly.

Ensuring Argon Retention
Some actions Ernst recommends to help maintain proper argon fill and retention rates include:

• Incorporate a quality-control program into your manufacturing process. Have quality control standards in place and take reasonable precautions to maintain these benchmarks.

• Document your manufacturing process. “Know the ingredients you’re putting into the pie and make sure you have the procedures documented,” said Ernst.

• Follow recommended manufacturing practices by industry associations. Citing recommended processes adds validity to manufacturers’ claims of argon retention and overall window performance.

“The industry becomes vulnerable because of manufacturers who do nothing,” said Ernst. “They have no quality-control program, no testing, no procedures and no documentation.”

Why Bother with Argon? 
Since manufacturers may not be sure that argon was put into a unit properly and it can sometimes escape, why does the industry continue to tout the use of argon in its IG units? This is because the benefits of filling units with argon far outweigh the risks associated with proper fill rates and gas retention.

“Argon is a natural add-on to low-E windows because it improves thermal performance significantly and adds insignificant cost,” said Joe Almasy, product specialist for TruSeal.
In addition, the existence of argon between lites of glass sealed with flexible warm-edge spacers warms the inside glass temperature, making room temperatures more comfortable in cold-weather climates.

Additional reasons for ensuring high fill and retention rates lie in the future of glass development. Ernst says new coated glasses—ones that change tint to alter the amount of light entering buildings—will be filtering into the industry over the next five to ten years. “For this new generation of coatings to be commercialized, they have to be in an inert environment,” said Ernst. 

While the inert gas doesn’t have to be argon, the key is, once again, to have a proper seal that keeps the gas in and oxygen out. However, manufacturers may choose argon to have the added energy performance benefits of the gas. 

Ric Jackson is director of marketing at TruSeal Technologies, based in Beachwood, Ohio. 


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