Repairing Double Glazed Windows Double-glazed Windows "blow" they let the insulating gas argon escapes, causing them to lose their energy efficiency. The good thing is that damaged double glazing is typically repaired without the need to replace the windows. The most typical indication of a failing window seal is condensation http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=1196518