Volume 14, Issue 1 - January/February 2013

AAMA Analysis

IG Certification
The Key to Performance Longevity
by Richard Rinka

The performance of the sealed insulating glass (IG) system is critical to the overall long-term thermal performance of a complete fenestration system. While technological advances have improved overall fenestration performance, they have also introduced variables that may impact the unit’s performance. As examples, loss of insulating gas or the deterioration of low-E coatings due to moisture intrusion can degrade insulating capability.

On July 1, 2010, the National Fenestration Rating Council (NFRC) began enforcing a requirement for third-party IG performance certification. As NFRC ratings are now required, the Energy Star® windows program also requires IG certification by reference. AAMA and Associated Laboratories Inc. jointly serve as one of four third-party certification bodies authorized to grant IG certification.

Testing Protocols
The typical process is for the IG manufacturer to assemble 12 identical IG test units, 14- by 20-inches in size, each with the same spacer and sealant combination for which certification is desired. This is done in the presence of a certification agency inspector, who permanently identifies each specimen and seals each with a tamperproof seal. The sealed samples and supporting data are forwarded to an approved independent test laboratory of the manufacturer’s choice for testing.

ASTM International publishes the recognized test methods and specifications for IG performance:

• ASTM E2190, Standard Specification for Insulating Glass Unit Performance and Evaluation, which provides the applicable test and assessment methods as the basis for evaluating the durability of IG units. The qualification of test specimens is based on frost/dew point and on the absence of fog after the specified test durations according the ASTM E2188.

• ASTM E2188, Standard Test Method for Insulating Glass Unit Performance, prescribes the durability testing sequence that encompasses periodic frost point testing per E546/E576 and spark testing of gas filled units per E2649.

• ASTM E546, Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units, is used to determine the frost/dew point within the air space[s]. (Alternatively, ASTM E576, Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units in the Vertical Position, may be used.)

• ASTM E2649, Standard Test Method for Determining Argon Concentration in Sealed Insulating Glass Units Using Spark Emission Spectroscopy, provides a means for determining the concentration of argon in sealed insulating glass units under controlled conditions in compliance with the apparatus manufacturer's instructions.

• ASTM E2189, Standard Test Method for Testing Resistance to Fogging in Insulating Glass Units, is used to show that the components in an IG unit will not out-gas a volatile vapor that could condense on the interior glass surfaces. Upon receipt of a Notice of Certification Authorization (NCA), the licensee may begin applying the AAMA/ALI IG certification mark to each unit of that product family and list the product in the AAMA/ALI certified products directory. Test reports are valid for 24 months from the date that the NCA is issued and then must be retested and validated in the same manner as for initial certification.

Plant Surveillance
Without prior notice, an ALI inspector visits the licensee’s manufacturing plant(s) twice annually to verify the continued use of materials and methods used to produce the originally approved samples. In addition, the inspector verifies the ongoing effectiveness of the manufacturer’s Quality Management System (QMS).

At a minimum, QMS requirements for IG manufacturers, as set forth in NFRC 706, Requirements for Participating Insulating Glass Certification Programs.

Note that while independent certification of IGs is not a prerequisite for certification of a completed fenestration unit to NAFS, NAFS compliance does require a test report showing compliance of the IG with ASTM E2190 or CAN/CGSB 12.8.

Richard Rinka serves as certification manager for the American Architectural Manufacturers Association in Schaumburg, Ill.


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