Thread: beads inside thermopane window

A couple of the windows in a condo I looked at today had some tiny beads in between the panes. The one in the photo had the most. I suspect they have something to do with the manufacturing process, and that they will not affect the performance of the windows.
Are they dessicant beads or something like that?
Thanks

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Since they are differant sizes I would not think they are beads.

They may be dessicant beads, but I have never seen them before. By the time you have a blown seal, that small amount of beads would be worthless anyway.

Could it be styrofoam beads from a sheet used to protect the glass prior to assembly that the assembler didn't clean off?

Originally Posted by Ken Meyer

A couple of the windows in a condo I looked at today had some tiny beads in between the panes. The one in the photo had the most. I suspect they have something to do with the manufacturing process, and that they will not affect the performance of the windows.
Are they dessicant beads or something like that?
Thanks

Ken,

My guess would be Styrofoam beads held to a single glass pane by static electricity prior to assembly.

Thanks for your replies. Most likely something that should have been removed during the assembly process. They do look like styrofoam. They won't do any harm, the homeowner knows they are there, but is not concerned.

They are desiccant beads. They keep the moisture out of the window. In most windows they are hidden in a channel that you can't normally see.

Thank you Scott. And now I know how to spell desiccant.

As Scott stated, they are desiccant beads. When the metal spacers that separate the glass lites are cut to size, they are filled with the desiccant beads prior to the IG (insulated glass) units being assembled. There are small caps that go in the ends to hold the beads in place.

So, are visable beads considered acceptable?

The loose desiccant beads are not an issue for repair, merely cosmetic. They will continue to absorb moisture for a while even though dislodged from the spacer unit.

Some folks may not know it, but the cause of fogging in thermal pane window units is not due to a loss of seal, but a failure of this desiccant. It is incorrect to think that there is a hermetic seal drawn on these windows. This is an impossibility (nature abhors a vacuum). So then, the seal that is initially accomplished is imperfect and leaks from the very beginning. That's right, they leak straight out of the factory. All of them leak. Telling your clients that their thermal windows are not leaking is just plain lying. A bit like telling a client in an area with known expansive soils that they have a stable foundation. Bullshit.

As soon as a thermal pane unit leaves the shop, it is destined for failure. Moisture diffusion into a sealed unit is impossible to avoid and continuous. Manufacturers deal with this reality by loading absorption material, or "desiccant" (usually a silica gel or similar material), in the spacer bar construction of every unit. This material has one job - to bond with water molecules. The material comes in the form of beads, similar to those you find accompanying new leather and electronic products, or as a blended compound, often a black butyl or cork-like wafer.

Every insulated glass unit (IGU) has a finite capacity for how much water it can hold ("hide"). Over time, as moisture accumulates, the unit finally reaches a threshold saturation point, it becomes visible as condensation between the panes of glass (this is directly associated to the falling dew point between the panes of glass).

More at:

http://www.dowcorning.com/content/pu...truction&DCWSS

Of course all of you IR-gizmo-wielding geeks knew this already, right? Right.

Aaron

Aaron,
Good info, thanks. I'll pass this along to the clients. I'm getting bids right now for replacement of an almost 9' x 6' picture window in my living room, it's fogged up. We replaced the single pane glass with thermopane 20 years ago when we bought the place, it failed within a year (still under warranty, thankfully), and now it's time again. This time we'll go with low-E glass.

Ken:

If they are not under warranty, depending on where you live, they may be repairable instead of replaceable (cheaper with better warranty). See:

Repair Foggy Windows & Condensation Problems Crystal Clear Window Works

Aaron

I've read about this process before, my understanding is that if the fogging gets past a certain point, the restoration process won't work. It would be worth having someone take a look at it, though.

Aaron, the material you posted seems to dispute your theory. (My underline)

Typical IG units are comprised of two
(or occasionally three) panes of glass with
a cavity between the panes. The panes of
glass are sealed around the perimeter with
a spacer and sealant system which ensures
that the units are hermetically sealed and
sufficiently stable to withstand thermal and
windload stresses on the unit. For a typical
“dual-sealed IG unit�, a polyisobutylene
(PIB) or “butyl� primary seal between the
metal spacer and glass provides low vapour
permeability and a silicone secondary seal
provides structural integrity for the panes of
glass.
For insulating performance, the space
between the panes of glass is filled with dry
air or more commonly filled with an inert gas
which provides enhanced thermal insulating
performance. To maintain the long term
insulating performance of the unit, the glazed
perimeter of the IG unit must have low vapour
permeability to resist an ingress of moisture
which can cause fogging of the IG unit. To
absorb incidental moisture that may enter
the void, a desiccant is commonly used in
the spacer element. All of these elements
must work synergistically to provide the
expected performance of the IG unit.

This seems to go along with my understanding and observed performance of IG systems. If desiccant failure rather than seal failure were the primary mechanism in fogged systems would we not expect to see all units in a given exposure fail in a nearly identical time line rather than the random pattern typically observed?
Granted, units of a particular age can be expected to have more failures than younger units, but this would be expected regardless of the mechanism of failure.
Thoughts?

If desiccant failure rather than seal failure were the primary mechanism in fogged systems would we not expect to see all units in a given exposure fail in a nearly identical time line rather than the random pattern typically observed?

Jim:

That expectation would assume may things.

First, that all of the units were identically constructed. This is unlikely, even in the best factory.

Second, that the units all had the same light exposure once installed. This is impossible in all but the most frugally and poorly designed buildings.

Third, that the units were all properly handled from the factory to their final installation point by all concerned. This is never going to happen.

Aaron

Originally Posted by Aaron Miller

As soon as a thermal pane unit leaves the shop, it is destined for failure. Moisture diffusion into a sealed unit is impossible to avoid and continuous. Manufacturers deal with this reality by loading absorption material, or "desiccant" (usually a silica gel or similar material), in the spacer bar construction of every unit. This material has one job - to bond with water molecules. The material comes in the form of beads, similar to those you find accompanying new leather and electronic products, or as a blended compound, often a black butyl or cork-like wafer.

I'm curious (the ex-school teacher part of me that is) - the quote above appears to be a slightly reworded version of the quote below. Why not just quote them directly with attribution? I was feeling all déjÃ* vu reading it until I figured it out.

Repair Foggy Windows & Condensation Problems Crystal Clear Window Works

From the moment an IGU leaves the shop floor, it is a candidate for failure. Moisture diffusion into a sealed unit is unavoidable and continuous. Manufacturers deal with this reality by loading adsorption material, or 'dessicant', in the spacer bar construction of every unit. This material has one job - to bond with water molecules. The material comes in the form of beads, similar to those you find accompanying new leather and electronic products, or as a blended compound, often a black butyl or cork-like wafer.

Nonetheless, I'm glad to know my IG windows will fail. I'll be even more interested to see if the tempered units fail at a different rate than the others. Or maybe I should just sell the house before that happens and hope for a friendly inspector.

Corn Walker

Or maybe I should just sell the house before that happens and hope for a friendly inspector.

Nah, just pray for one of the recent profusion of IR-whizbang slingers. You're sure to slide on your window inspection while they busily illustrate to the prospective buyer where you walked after taking your morning shower. Dimwits with rayguns.

As for the apparent (and very obvious, even to the slowest amongst us) rewording, as a teacher you should know that there is nothing, I repeat nothing, that has not been said before. You though, may be the only one on earth with both original thoughts and statements with which to astound and amuse the rest of us dullards and plagiarists.

By all means carry on,

Aaron

Originally Posted by Aaron Miller

that there is nothing, I repeat nothing, that has not been said before.

Aaron,

Are stating, then, that you are only repeating yourself every time you post?

Or, that we should simply post, for each inquiry, "That has been asked and answered before, go back and find it."?

Originally Posted by Aaron Miller

Nah, just pray for one of the recent profusion of IR-whizbang slingers. You're sure to slide on your window inspection while they busily illustrate to the prospective buyer where you walked after taking your morning shower. Dimwits with rayguns.

Will they be able to tell I take my showers in the evening rather than the morning? If so, I'm going out right now to get me one of them ray guns.

As for the apparent (and very obvious, even to the slowest amongst us) rewording, as a teacher you should know that there is nothing, I repeat nothing, that has not been said before. You though, may be the only one on earth with both original thoughts and statements with which to astound and amuse the rest of us dullards and plagiarists.

Well... it struck me as funny, seeing as I thought it would have simply been easier to copy/paste than to reword it (maybe that's just because I'm lazy). There is plenty that has not been said before, but when it has been said before the customary thing to do is to quote and provide attribution.

Corn Walker

Will they be able to tell I take my showers in the evening rather than the morning? If so, I'm going out right now to get me one of them ray guns.

Depends on the cost of the gun. The more money the more rays.

quote and provide attribution

Even though you just quoted me several times, you did not reference the author. I'm calling my agent . . .

Aaron

Are stating, then, that you are only repeating yourself every time you post?

Or, that we should simply post, for each inquiry, "That has been asked and answered before, go back and find it."?

ECJ:

Yes, it's an akashic record sort of thing then isn't it?

Aaron

Originally Posted by Aaron Miller

ECJ:

Yes, it's an akashic record sort of thing then isn't it?

Aaron

Aaron,

I'm just a simple small town boy, so you need to keep you words simple for me, such as i-t-'-s a-n (WTF?) r-e-c-o-r-d t-h-i-n-g-y.

i-t-'-s a-n (WTF?) r-e-c-o-r-d t-h-i-n-g-y.

ECJ:

My sentiments, precisely.

Akashic records - Wikipedia, the free encyclopedia

Aaron Ohm . . . . . . . . . . . .

BTW, does anyone have a link to a good discussion of how much thermal performance actually declines when the seal fails?

Michael:

http://www.cbe.berkeley.edu/research...inalReport.pdf

I think it's in here at the beginning somewhere, don't have time to look right now. With no inert gas present between the panes I am assuming that the U value will be the sam as that of a single pane unit.

Ask Peck, he knows everything . . .

Aaron

Thanks.

BTW, does anyone have a link to a good discussion of how much thermal performance actually declines when the seal fails?

I ask that question of one of the engineers from the window rating compliance folks at a recent continuing ed course. His answer was a "something on the order of 10% degradation."
Also, I believe in the same talk, it was brought up that there is not much Argon, nitrogen, etc. actually left in the cavity after the manufacturing process.
Really, the only difference is the thermal conductivity of the vapor that fills the space, since even when the seal leaks out all the good stuff, you still have dead air, which is the same thing that does the actual insulating in fiberglass and cellulose insulation.

Sounds reasonable - I wish I could find that opinion in writing from an industry source..

Multi-pane windows are all the rage here in sunny San Diego where the Marine Corps and the Navy flies their helicopters and airplanes anywhere and everywhere at all hours of the day. The only place they don't fly is over the airport, but the airport has its own noise problems in the flight paths, so it just doesn't matter where one goes here in the County. If one buys a home on the Point Loma peninsula, the City of San Diego even has a "noise abatement" program where they pay a lot of money to replace the outdated windows in the home with new, noise-reducing, multi-pane windows. It's a very lucrative program--might have something to do with why the city's pension fund is a few billion dollars in debt and five of the city councilmembers are under indictment for various items involving the city's finances. Anway, I digress....

Whenever I find condensation between the panes, I just state that the window unit as designed has failed. I'll let the window guys determine which part has failed and whether or not it is fixable or must be replaced.

Originally Posted by Michael Thomas

Sounds reasonable - I wish I could find that opinion in writing from an industry source..

Me too, almost. It certainly seems to me that the quoted 10% depreciation estimate is a very low one. If not, then why put the gas in there at all? That's especially true when you know it is leaking out from the minute you put it in there. Wasted effort from my point of view. Additionally, unlike storm windows which usually have a lot of dead air space comparatively speaking, it seems that these windows with 3/8" to 3/4" air space would provide minimal, if any, insulative ability.

So, Jim, show me . . .

Aaron

This thread could and should continue because there are many issues regarding multipane windows.

A few days ago I called attention to two South facing sashes that had non-random streaks and varying sized spots on the inner surface of the outer pane (lite).

I gave the weasel broker a head start to try and counter my quick assessment on these newer (1-2 year old) low end plastic replacements.

(This very same weasel said the flat roof of this 18 unit condo was new rubber and had been OK'd by several inspectors) ( He said the roof was not accessible but I ignored him and went to the penthouse and opened the door and found an alligatored 30 year old Modified Bitumen with 1-5 years left)

Back to the low end plastic windows. My instant opinion was failed emissivity membranes. Better IR & UV barriers are applied by a process called "Sputtering"

(In the end he could not defend his weasel statement that the nearby tree branches had scraped the windows and had to admit that the problem was indeed on the interior but this took a lot of his and not my time.)

Can anyone add to or refute my opinions.

Can anyone add to or refute my opinions.

I don't think anyone has ever had any success with that, Ken.


Back on topic...Here's a couple of good articles on insulated windows.

Old House Journal Online Traditional Products

Understanding Energy-Efficient Windows - Fine Homebuilding Article

On the 10% depreciation thing of a failed seal...
The 2nd article has a chart showing about a 10% difference in overall heating costs between air-fiiled double panes and a low-E coated, argon filled units. This is in a decently insulated home with the "usual" square footage of windows. Obviously heat is also lost elsewhere in a house and as the 10% difference in heating costs was due to changing the windows, and nothing else, the actual difference in the windows themselves must be significantly higher. How much...I don't know, and part of that difference would be due to the coatings. In other words...I've probably been no help at all!

I remember seeing a very good visual demonstration on a TV "How-Do" type show of how the more viscous gases (argon & krypton) slowed down the air-currents between the panes and thereby reduced heat loss. It was a few years back. It may have been a series called "Deconstruction", but I'm not sure of that.