First off the gas leaking out did not cause the panes to collapse. This was caused by another problem had in the early nineties, I cannot remember exactly what the trouble was but I remember the panes actually bowing in and eventually breaking but not from the gas leaking

sdavidmaster,

I am a bit confused by your post - did you replace all 33 IG units and then 6 of the replacements failed as well? Or did you replace some of the original's and then six more at a different time?

What you describe is a classic example of collapsed glass.

For a bit of background, collapsed glass is not a seal failure, in the sense that there was a physical breach in the IG seal system, rather collapsed glass occurs in argon-filled windows when the argon decides to leave the IG airspace (yes, collapsed glass is due to the gas leaving the IG space)and it isn't replaced; resulting in a partial vacuum within the IG airspace which draws the panes of glass inward.

The simplest fix for collapsed glass is to vent the airspace by drilling a tiny hole either thru the glass or thru the IG spacer, as your rep described, which will allow air into the space, equalizing pressure. The hole is then sealed and the window is again performing at close to the original energy performance specification - less the argon fill.

Collapsed glass is directly related to the materials and techniques used to manufacture the original IG units. At the time yours were made they were state-of-the-art and no one had even the slightest idea that argon could dissipate thru the spacer material without being replaced by air or that collapsed glass was even possible.

Modern materials and manufacturing techniques have virtually eliminated this problem (with a few very rare exceptions - almost always related to human error), but back in the early 90's, when your IG's were fabricated, there was no concept that it was even possible.

Ironically, collapsed glass ultimately means that the IG's were well made and that the seals have held up very well over the years.

Collapsing can result in broken glass in the right circumstances relating to the width of the airspace, versus the size and aspect ratio of the IG unit.

Thanks for the history, information and the experiences with Anderson windows. However, my query/concern was to the effectiveness of the air as insulation versus Argon gas that was replaced by ambient air as a permanent solution by Anderson.

I understand there are class action suites against Anderson windows in couple of states for very issue about the Argon fill and the leak; has there any resolve as to the insulation issue?

The information was not exclusive to Andersen. There were other companies that experienced the same issue as well as Andersen.

Air is an effective insulator in an IG unit space. It isn't as good as argon; Argon will improve the U-factor of a window by about .03 over air fill.

I have never heard of a lawsuit against Andersen (or any other window company) over argon dissipation loss - which is what you have experienced.

Have a 4 sach anderson bay casement window that I put in 1991 or thereabouts. Has leaked on 1 sach for several winters now, namely a big oval on inside. Well I called Anderson this morning and the nice lady, Theresa, took info and is going to send a replacement. How about that for service! Have Anderson in the rest of house and love them. Nice to see someone stand behind something for a change. While I was at it I had a bad latch on a double hung and she is sending that also. Am happy with the service Anderson gives and would recommend them to all.

paulmichael, your problem is not from the leaking gas but just a seal failure(which inturn allows the gas to escape and lets moisture in) Andersen has a 20 yr guarantee on the glass from this type of problem

Paulmicheal the condensation oval inside is classic collapsed glass which will appear only when it gets cold outside. It's great they are sending you a new sash under warranty. I wonder what will happen when these units are past their covered 20 years? I imagine when people find out they have a house full of windows that had a known defect for years that is now not covered things are going to get interesting. There is a house down my street that has at least 40 defective sashes that are clearly visible driving by... on these cold days the water is just running off the glass.

The other interesting thing these collapsed sashes do is melt the neighbors vinyl siding in the summer.... Oh my that's a mess.

Well said brickeyee. There is quite a bit of confusion on this issue and you are clearly up to speed and completely correct.

We just had a second IGU fail at work last week.

They are all about 30 inches wide and over 6 feet tall.

It makes a nice loud 'thud' when the tempered glass lets lose.

The outer pane failed on this one (previous one was the inner pane).

We now more are coming since you can see the flex in many of the windows, but the landlord is happy to just wait till they fail.

Since they are all tempered glass it is not much of a safety hazard, but it sure made the boss jump.

I have the same streaks on 2 of my 12 windows. Not condensation. Did Andersen ever work with you?

Streaks in the in between the panes should be under warranty if within 20 years and you are original owner or transferred the warranty. It

mau be easier if you go through your installer or vendor but you can contact Anderson. Labor is typically not included. Might want to start a new post with more details.

Tony Lucich,

Not sure what you mean by "streaks". Can you define, or better, can you post pictures?

Are these new windows or have they been around for awhile?

That could be moisture.