New ASTM IGU standard contributes to testing for energy efficiency of windows

Inert gases in insulating glass units help make windows more energy efficient. A new ASTM International standard provides a long-needed method for evaluating gas concentration inside insulating glass units without destroying or altering the edge seal. The new standard, ASTM E2649, Test Method for Determining Argon Concentration in Sealed Insulating Glass Units Using Spark Emission Spectroscopy, has been developed by Subcommittee E06.22 on Durability Performance of Building Constructions, part of ASTM International Committee E06 on Performance of Buildings, according to a July 16 release. “The inert gases that are often contained between the panes of glass that make up an insulating glass unit provide better thermal efficiency and reduce heat loss through the window,” said Jeffery Haberer, technical services engineer, Cardinal Glass Industries, and E06.22.05 task group chair, in the release. “While the inert gas is only one component of a window that reduces heat loss, if the inert gas leaks out, the total potential to reduce heat loss is compromised.”Haberer notes that, for a test on gas loss, it is necessary to know the concentration prior to weather cycling and after. “Previously, IG units were either altered with a septum for gas sampling or the edge seal of the IG was destructively broken in order to sample the gas content,” he said in the release. “Neither of these procedures lended well to the need. Until now, there was no nondestructive test method to sample gas concentrations in IG units.” According to Haberer, certification groups and researchers will use ASTM E2649 to show the compliance of an IG unit to hold gas at a minimum accepted level.ASTM Committee E06 meets Oct. 18-21 during October committee week in Atlanta.