[Greenbuilding] windows better than walls (was Vacuum, insulation panels...)

[stephen at thermotechfiberglass.com]

Vacuum Glazing

Aside from the pillars i have 2 other concerns about vacuum glazing 
that will limit its application in heating climate housing.

1. The edges are conductive, even w/ the best insulating material as a 
spacer, there won't be enough of it to remotely qualify as warm edge. 
The solution mention by most is to bury the edge deep into a frame -- 
reducing glass area and solar gains.....

2. To get the best insulating value potential fabricators are using the 
lowest emissivity low-e - which severly limits solar gains

These 2 items may not be that much of a drawback in the commmercial 
world where internal gains means that the heating season is much shorter 
than it is for houses in the same climate.

In the end, like John, i'm not holding my breath.....

Stephen




On Sun, 6 Nov 2011 02:37:52 +0000, John Straube wrote:
> We tested some Guardian units a couple years ago and you can buy
> units from Japan. They can and do work.
> But to keep the panes separated when pushed together by 15 psi you
> need closely (say 4") spaced posts. These tiny posts act as thermal
> bridges and limit the R-value.
> To date their only benefit is that they can be thin. For less cost
> and technology we can use multi-pane low e gas technology.
> Until someone comes up with a completely different way of doing this
> glazing there won't be a break through.
>
> Sent wirelessly from my BlackBerry device on the Bell network.
>
> -----Original Message-----
> From: Philip Proefrock <architect at cornellbox.com>
> Sender: greenbuilding-bounces at lists.bioenergylists.org
> Date: Sat, 05 Nov 2011 19:53:18
> To: <greenbuilding at lists.bioenergylists.org>
> Reply-To: Green Building <greenbuilding at lists.bioenergylists.org>
> Subject: Re: [Greenbuilding] windows better than walls (was Vacuum,
>  insulation panels...)
>
> How about the concept of vacuum-insulated glass windows?
>
> I agree that vacuum insulated panels are probably mostly specialty 
> items
> (shipboard refrigerators; shipping container architecture; maybe some
> special retrofits of existing buildings), but vacuum-insulated glass
> windows could be another thing entirely.  Instead of using an inert 
> gas
> in a double pane window assembly, the intervening space is evacuated.
>
> When I was looking at the concept a few years ago, Guardian was 
> hoping
> to have commercial production underway by 2009.  But I haven't heard
> much more about it, and as far as I know, no one is making them.
>
> I'm sure that maintaining the vacuum is an issue, but it shouldn't be
> insurmountable.  I'm curious if anyone else has heard anything more
> about this.
>
> Philip Proefrock
>
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