Double Glazing Unit Repair Double Glazing that is hazy or cloudy, or that is not able to be cleaned has probably been "blown". This occurs when the gap between the window panes expands due to the deterioration of the window seals. It is much cheaper to replace the double-glazed unit http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=1212596