Surprisingly, no glazing is vacuum sealed because it would put the two panes of glass under pressure and sooner or later The 2 panes would touch. Factory equipped double glazing is hermetically sealed, indicating that no air can enter or escape. ® will decrease the heat loss by much more https://stephendsfse.blogzet.com/helping-the-others-realize-the-advantages-of-soundproofing-49396609