Hi all, Just wondering if anyone has heard of or has experience with Vacuum Sealed Windows (VIG). There's a link, at the bottom, to an article I found. Kind of funny, I left some coffee in one of those insulated coffee carafe's for over 12 hours and noticed it was still warm. They just have a double layered vacuum sealed glass container inside. Vacuums are supposed to be the best insulator. So, I got thinking... why don't they make windows like this. Sure enough, there seems to be some manufacturers on google, but not quite popular yet. Just wondering if any of you have experience on the topic. Thanks, R http://homerenovationtrends.wordpress.com/2008/08/08/vacuum-insulated-windows/

Product News from Environmental Building News
February 1, 2008
Revolutionary Vacuum Glass Coming from Guardian
Guardian Industries, one of the world’s largest architectural and automotive glass manufacturers, with 19,000 employees in 25 countries, has under development a revolutionary vacuum-glazing panel that provides a center-of-glass insulating value of R-12 to R-13. The glass—Guardian VIG (for vacuum-insulated glass)—has a very thin (250-micron or 0.25-mm) space evacuated to 10–4 torr (for reference, thermos bottles typically have a much harder vacuum of around 10–6 torr) between two layers of glass, one of which has a low-emissivity (low-e) coating. Guardian is currently producing the vacuum glazing on a limited basis for testing and hopes to roll it out commercially by the end of 2009.

The problems have been developing seals that can be long term guaranteed and the visibility of the spacers that are needed to hold the pieces of glass apart.  Also, getting the panes of glass to be flat (meaning the spacing, size and compressibility of the spacers) to avoid visual distortion has been a challenge.  Guardian is using a very, very small space (0.25mm = .010") between the glass panes to combat these issues.

It sounds like they may have it sorted out soon.

Bruce

Thanks for your feedback everyone. It would be a great product if they figured out the quality/reliability issues.

Regards,

R

You may want to look at ; http://spie.org/x8586.xml?ArticleID=x8586 for more info

Take a close look at Figure 4. In their approx 16"x16" sample the difference between the center of glass insulating value and the overall insulating value is about almost 50% for the lowest emissivity low-e (about R-11 vs about R-6 in imperialistic units)

In other words there are some cold edge issues, in addition to those mentioned previously.