Seeking advice on replacement of Dual-Glazed Glass Panels only

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patrick_here
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Seeking advice on replacement of Dual-Glazed Glass Panels only

#1 Post by patrick_here »

Hello,
I'm looking for advice on replacement of the Dual-glazed Glass Panels only (not the entire window frame unit).

I live in Washington state (cold in winter), house a year ago. It has Vinyl-Clad windows (double-hung and Solid pane) with dual-glazed glass. Most of the dual-glazed Glass Panels are "blown" ...ie: on very careful inspection it's possible to detect that moist air has entered most of the windows. The house is 24yrs old (original glass); single story about 1800 sq ft.

MY QUESTION:
It will be expensive to replace most of the glass in this house. I am wondering what to expect in terms of increased insulation after spending all that money. I have a little infrared temperature sensor that can measure the surface temperature of the glass. When I go through and measure the inside temperature of the glass and compare the blown panes to the good panes the difference seems quite minimal (on the order of one degree farenheit). So if I spend all this money to replace all this glass, should I really expect a difference in insulation level? Or should I be prepared to find that after spending all that money the only measurable difference will be that the minor telltale signs of "blown" panes (which is almost imperceptible now) will be gone and I will have glass that looks brand new?

I'm really looking for input from professionals who have years of experience with dual-pane replacements. Thanks in advance for the help.

-Patrick

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HomeSealed
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#2 Post by HomeSealed »

The performance difference will not be substantial in all likelihood. Even though the seal is broken allowing some moisture intrusion, its not like you have air flowing freely between those panes. The airspace is still close to dead (good for insulating), probably similar to the space between a prime window and storm.

With that in mind, I'd suggest waiting until full replacement of these windows is doable for your.
1) You stated that the visible obstruction isn't awful
2) If you have a home full of bad seals, these window are likely at the end of their service life, and that condition suggests that they probably weren't that great to begin with. As you've stated, spending a bunch of money to get a minimal performance improvement may not make much sense, especially if you'll still be stuck with marginal windows.

Oberon
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#3 Post by Oberon »

I agree with HomeSealed's reply.
Seal failure is more about aesthetic than performance.
Replacing the bad IG units isn't going to result in any sort of significant improvement.

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TheWindowNerd
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#4 Post by TheWindowNerd »

Several thoughts come to mind.
If you have only been in the house for one year, did any of the seal failure show up in the home inspection report?

Seal failure in 24 year old builder grade window is a long life cycle. Builders grade products usually are not draft free and sometimes do not include low e argon.

You should get pricing to reglaze all the glass with dual pane low e argon. Glazing beads in 24 year old vinyl can be a problem.What other issues do the windows have to compare the value to replacing the windows such as screens, balances,and compression settlement?

Get a price to replace the windows with something that is u .26 and < .04 AL. You should also get a additional bid for triple pane.

wayne theWindowNerd

patrick_here
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#5 Post by patrick_here »

Thanks Wayne and Oberon and HomeSealed,
Wayne, yes my (buying) Realtor did spot that there was a problem with the windows but we didn't realize quite how expensive it was going to be. We weren't able to get the seller to budge the price on it (competitive issues).

I think I'm going to order a higher quality infrared temperature sensor to get a more reliable picture of what I'm really dealing with. This gentleman from Virginia seems to have some very reliable data using an infrared sensor:
https://www.youtube.com/watch?v=IdJbH6KLrx0

His measurements certainly suggest that the presence or absence of argon makes a huge difference in insulating potential. I have every reason to believe that there isn't any air "flowing freely between the panes" of my windows (though I can't be sure), and I think they didn't have argon originally (they definitely didn't have a Low-E coating). There seems to be no mention of Argon in the documentation from the builder. One related question: If a window originally had argon and 24 years later it has visible evidence of moisture (like mine), such as a "snowflake pattern" barely visible on the inside surface, does this mean that the argon is all gone? Isn't it possible that if the windows originally had argon that they could end up with a snowflake pattern even if some high-humidity outside air entered in between such that perhaps 80% of the original argon still remains inside but 20% of it has been replaced by outside air?

I'm probably going to have these panels furnished and installed by a local glass company ...and it seems that these companies have the dual-glazed panels made up by some third party manufacturer. Is there a way for me to know which of these third party manufacturers produces a longer-lasting product?

Also, a question regarding the low e coating: One of the window contractors mentioned that when panes with a low-e coating start to deteriorate (due to moist air entering the chamber), they can tend to go downhill very fast because the metal particles used for the low-e coating are actually corroding. Is that true?

Thanks again for all the help.

-Patrick

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TheWindowNerd
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#6 Post by TheWindowNerd »

The minimum full warranty that you should look for is 10years, hopefully you will get 20 year.
You want low e argon and a low conductance spacer, non metallic or stainless steel.

theWindowNerd

Oberon
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#7 Post by Oberon »

I think I'm going to order a higher quality infrared temperature sensor to get a more reliable picture of what I'm really dealing with. This gentleman from Virginia seems to have some very reliable data using an infrared sensor:

The infrared thermometer he is using in the video runs about $100 or so, but what exactly are you hoping to find with one? Ultimately if you have seal failure, the glass is going to cloud up inside and look terrible. As mentioned earlier, seal failure is less a performance issue than it is an aesthetic issue, but if your original IG was so equipped you would lose argon fill and any sputter-style LowE coating would corrode.

His measurements certainly suggest that the presence or absence of argon makes a huge difference in insulating potential.

Actually his measurements are more about the LowE coating and less about argon fill.
A 100% argon fill increases window energy performance by about 16% and about 8% at 50% fill. Argon volume versus energy performance is a linear improvement and it works primarily by slowing convection currents within the airspace. Although there is a test device to measure argon fill in a window, it's very expensive and not available to the general public. There is no way for a homeowner to accurately determine if your IG units have argon or not, but if you have 24 year old builder-grade vinyl then I would say that it's pretty close to 100% certain that your IG units never had argon to start.

I have every reason to believe that there isn't any air "flowing freely between the panes" of my windows (though I can't be sure),

Air "flowing freely" between lites in an IGU is a bad thing, but I am not sure exactly what you are asking?

and I think they didn't have argon originally (they definitely didn't have a Low-E coating). There seems to be no mention of Argon in the documentation from the builder.

I would agree with your appraisal.

One related question: If a window originally had argon and 24 years later it has visible evidence of moisture (like mine), such as a "snowflake pattern" barely visible on the inside surface, does this mean that the argon is all gone?

If you have evidence of moisture inside 24 year old IG units, then yep, any argon would have packed it's bags and headed out the door long ago. It's gonna be gone.

Isn't it possible that if the windows originally had argon that they could end up with a snowflake pattern even if some high-humidity outside air entered in between such that perhaps 80% of the original argon still remains inside but 20% of it has been replaced by outside air?

Nope, doesn't work that way. If there is an opening that lets air in, then it has displaced the argon in the airspace.
Well technically you would still have about 1% argon, because that's how much is in the air that we breathe.

I'm probably going to have these panels furnished and installed by a local glass company ...and it seems that these companies have the dual-glazed panels made up by some third party manufacturer. Is there a way for me to know which of these third party manufacturers produces a longer-lasting product?

You could always ask them, that's what I would do. No other way to be certain that I can think of...unless the IG manufacturer labels their product. Unlikely from a mom-and-pop operation though. Also since you don't know where the IG is coming from, how do you know the quality or how long it will last? What's the warranty, if any?
Heck you can buy IGU spacer material from Amazon if you wanted to make your own IGU's. Certainly not something that I would normally suggest, but initially at least it would be the least expensive option and you would know what you were getting.

Also, a question regarding the low e coating: One of the window contractors mentioned that when panes with a low-e coating start to deteriorate (due to moist air entering the chamber), they can tend to go downhill very fast because the metal particles used for the low-e coating are actually corroding. Is that true?

Yep, although there are other factors related to where you live and local environment,in general seal failure is going to result in coating corrosion (assuming a softcoat LowE between the lites).

Just a recommendation, but replacing bad IG units in 24 year old builder grade vinyl windows is a false economy. If you are concerned about the look and the performance then you will get improvements to both (assuming adding LowE and argon to replacements, when the originals had none), but if your only concern is saving $$$ by improving energy performance, then the payback will likely exceed the life of the windows.

You will be much better served by looking at replacing the original units with something of better quality. There are various options available, and while I am far from an expert on what would best fit your specific needs I would probably opt for a full replacement of the original units...which is unfortunately the most expensive option.

Otherwise, I would ask the guys in this forum for their recommendations. There is a lot of professional expertise on this site specific to your best options.

patrick_here
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#8 Post by patrick_here »

Oberon wrote: Tue Dec 08, 2020 10:06 am ...If you are concerned about the look and the performance then you will get improvements to both (assuming adding LowE and argon to replacements, when the originals had none), but if your only concern is saving $$$ by improving energy performance, then the payback will likely exceed the life of the windows.

You will be much better served by looking at replacing the original units with something of better quality. There are various options available, and while I am far from an expert on what would best fit your specific needs I would probably opt for a full replacement of the original units...which is unfortunately the most expensive option.

Otherwise, I would ask the guys in this forum for their recommendations. There is a lot of professional expertise on this site specific to your best options.
Thanks for the reply. No, I'm not hoping to "get my money back" in saved energy over any multiple-year period. That's not why I was asking. There's nothing wrong with the appearance of the vinyl-clad window frames. But the deteriorated appearance of the glass is visible enough on many of the openings to make me want to fix it now because putting it off longer does not make sense. Perhaps the Infrared thermometer idea is a bit overkill but it's nice to have a good one around the house anyway ...they can come in handy on many occasions.

I was asking about the Low-E/Argon because I was having difficulty deciding on whether they were really worth the extra expense at all (ie: whether they really add a measurable insulation value). My decision now is that since I'm going to replace the dual-pane panels anyway, I've decided to go with the Low-E and Argon because I want the added insulation.

Thanks again,
-Patrick

Oberon
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#9 Post by Oberon »

All good then

What are they telling you about the replacement IG units?? Are they supplying you with any technical information?

patrick_here
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#10 Post by patrick_here »

Oberon wrote: Fri Dec 11, 2020 1:23 am All good then

What are they telling you about the replacement IG units?? Are they supplying you with any technical information?
No, not really. Some seem to be saying that Argon is not worth bothering with.


Incidentally, although I set this forum/BB to notify me when a reply is posted, I never get a notification when someone replies to this thread. Not sure what might be causing that.

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TheWindowNerd
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#11 Post by TheWindowNerd »

The LEA will act like triple pane( if the TP were with out LEA).
Depending on the OD of the glass and size I would consider DSB as a option.
You have the two parts that every project has, actually more, product and labor.
On the product side you want clear DSB LEA low conductance spacer with a 20 year full warranty.
Installation should be done by someone that is used to doing reglazing, provides an adequate warranty(2 years),
and will wet glaze your project.
If you were in my area I would think due to the volume you might be $125 per piece.
theWindowNerd

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HomeSealed
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#12 Post by HomeSealed »

TheWindowNerd wrote: Mon Dec 14, 2020 6:20 am The LEA will act like triple pane( if the TP were with out LEA).
Depending on the OD of the glass and size I would consider DSB as a option.
You have the two parts that every project has, actually more, product and labor.
On the product side you want clear DSB LEA low conductance spacer with a 20 year full warranty.
Installation should be done by someone that is used to doing reglazing, provides an adequate warranty(2 years),
and will wet glaze your project.
If you were in my area I would think due to the volume you might be $125 per piece.
theWindowNerd
You must have some cheap glass shops around you Wayne, I'd see a bit higher cost here.

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toddinmn
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#13 Post by toddinmn »

That would be a good labor only price.

patrick_here
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#14 Post by patrick_here »

TheWindowNerd wrote: Mon Dec 14, 2020 6:20 am ...and will wet glaze your project.
I don't understand why I would want to wet glaze when these are vinyl-clad? It's just double-stick tape on the inside and a snap-in vinyl trim on the outside and the frames are all in good condition.

Delaware Mike
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Re: Seeking advice on replacement of Dual-Glazed Glass Panels only

#15 Post by Delaware Mike »

As opposed to glazing via double-siding glazing tape in factory controlled conditions by experienced glazing staff, us field guys will remove the old glazing tape or glazing sealant as much as possible with scraping and prepping the mating surfaces with product like denatured alcohol, and then we pretty much lay a bead of dedicated clear glazing sealant. This allows us to move the IGU slightly when set to properly and equally place in the sash atop the glazing shims and make sure it's centered. If you attempt to add double sided glazing tape in the field you have one attempt to achieve contact and then you cannot move that IGU around if it's not exactly where you desire it. There is a tolerance in the sash. You want the visible spacer from an interior view to look centered and like it came from the factory. Some pros will spray glass cleaner type Windex atop the glazing tape adhesive to allow a slippery surface to tweak the placement and then the cleaner will evaporate allowing to dry and set up. I prefer to wet-glaze for that reason, too much to go wrong. Hope that sheds a little clarity on Window Nerd's brief mentioned on setting replacement IGU's in the field.

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