Is Argon a waste of money? Does is disipate over time?

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gigglebeans
Posts: 5
Joined: Sun Apr 09, 2006 2:39 pm

Is Argon a waste of money? Does is disipate over time?

#1 Post by gigglebeans » Thu Apr 13, 2006 11:18 pm

I was told by the Milgard salesman that the Argon was a option in their windows and not included in the quoted price. He said he felt like it was a waste of money since it disapates over the years. Is this true? Is argon worth the extra money to have in the window? HELP!! I'm confused yet again just when I thought I had made a decision.

windowguru
Posts: 46
Joined: Mon Sep 12, 2005 3:28 pm

#2 Post by windowguru » Thu Apr 13, 2006 11:32 pm

that is not a ringing endorsement of his window. Argon or any gas, does not instinctively find it's way out of the window. However, If the window's IGU is properly sealed it can stay there a long long time. I don't know much about Milgard but that salesman needs some lessons. Perhaps some of the vets can offer an opinion.

Oberon
Posts: 226
Joined: Thu Oct 07, 2004 10:25 am
Location: East of the Mississippi

argon

#3 Post by Oberon » Fri Apr 14, 2006 7:24 am

I almost wonder if the salesman was playing "your good old boy best buddy by offering a dirty little secret to let you know that he has only your best interests at heart and you really should buy from him since no one else is looking out for you like he is.... :wink: "

Anyway, this is a bit of an older post of mine, but I think it applies in this case...there is a bit of extra data that wasn't part of the original question, but I have never been known to let that stop me :roll:

There are a couple of different ways to fill an IGU with argon. The vacuum method is not the most widely used and it is not cheap...the cost for development and equipment runs into the millions of dollars...so one may ask why make that investment for something that is not reliable – for including a product that is going to fail? For something that can be done for much less money and for something that people may not even want because it may be a waste of money?

The cynical answer might be that it is possible to fool enough people into buying argon fill, even if it isn't worth it, in order to make a profit while paying off the high-tech process. But then there is the question, "why bother to invest in R&D and new equipment if quick profit is the only issue?" And if a company’s reputation rests on a product or process known by the company to be a failure?

There was a time when argon life-expectancy in an IGU was 5 to 7 years or possibly less. There was also a time when 8%-10% of all IGU seals failed in less than 10 years.

Unfortunately, for some manufacturers and manufacturing methods, those numbers haven't changed much, even today. But, for others, there have been significant improvement that is reflected in the products that they produce.

Argon leaks out of an IGU in two ways...slowly, over time by migrating thru the seal that joins the spacer to the glass in the IGU, or quickly, when that seal fails.

Most IGU's are constructed with desiccant between the lites to absorb excess moisture. This results in an internal (between the lites) dew point that is very low and helps keep the glass clear even in extremely low temperatures. This may also help to keep the IGU from fogging in the event of a seal failure.

If the seal fails, then the argon is replaced by air. For awhile (long while in a warm and dry environment) there is no evidence that the seal has failed. In fact, the overall performance of the unit (except for the argon loss) doesn't really change. The problem is when it gets cold enough to allow condensation within the IGU, then you will have fogging...or else, if the unit has a LowE coating, then that coating may begin to corrode when exposed to the air - if the desiccant becomes saturated and is no longer able to remove moisture from the environment.

But, beyond seal failure, there is also the argon's "ability" to migrate thru the seal itself; which does not result in air replacing the argon. The argon level has gone down, but nothing has replaced it.

Many materials have been used in an attempt to keep IGU's sealed both to keep argon in and outside air out. Since argon is a very small molecule, it migrates quite readily thru many materials; very few of the materials used in IGU spacer systems in the past could block argon migration for any length of time. Actually, keeping argon contained in an IGU for even 7 years or so was something of an accomplishment - but, obviously, it was not sufficient.

Without going into the history of seals and sealants, the best product currently in use to stop argon migration is polyisobutylene or PIB. PIB is a thermoplastic material and it is the only plastic currently known that is impermeable to gas - including argon. The TPS system is primarily PIB (85% if memory serves). Unfortunately, PIB is not a structural product, so it requires a second material to structurally bond the glass…specially developed silicones are used for this purpose as are hot-melt butyls and polysulfides. The PIB and silicone dual seal system is widely used among the largest window manufacturers in North America.

Another popular system uses foamed silicone as the primary spacer material (versus a metal spacer) and then wraps the silicone foam in a mylar film for gas impermeability since silicone alone will readily pass both moisture and argon. This system then uses a dual-seal that incorporates acrylic adhesive for its structural seal backed with a moisture vapor seal as well.

The point being that the primary manufacturers of both of these seal systems have spent huge amounts of money to develop testing equipment to check on both seal longevity and argon gas retention.

Additionally, outside corporations have also developed test devises for this purpose as well. These systems are now being used to track product performance both in laboratory and in field settings. The results in both settings indicate that argon loss is realistically estimated and measured at about 1% per year – in the top-of-the-line systems - seal failures have gone down to well below 1% over 20 years from as high as 8% - 10% over ten years – before the development of these new systems. In fact, the major IGU manufacturer in North America has reported that with their newest system seal failures are presently somewhat less than .1% over 20 years (one-tenth of one percent)…

The fear of losing argon from an IGU and the hesitancy of buying an argon-filled unit was valid a few years back – and still is with some systems even today, but the best systems on the market today have reached a point where avoiding seal failure and maintaining argon retention have become almost routine – something no longer a significant concern for the consumer.

Building Science for an example actually does recommend argon filled units, for their superior insulating capability, in several of their examples.

Hotshot
Posts: 3
Joined: Wed Apr 19, 2006 3:33 pm

Leaky argon

#4 Post by Hotshot » Wed Apr 19, 2006 4:07 pm

Milgard windows use an aluminum metal spacer that is more prone to leaking than any of the "warm edge spacers" The chances of leaking are rare in any commercially available window, but they greater in a window with a ridged aluminum spacer like the one in Milgard. I will give you my professional advise as someone who has been in the window business many years. Stay away from Milgard, and forget the argon. Argon gas will dissipate at a rate of 10% per year, and only improves the efficiency of the window by -.01 to -.03 u-factor. Such an improvement will never be visable on your gas and electric bill, and would never justify the added cost to the window.

windowmann2000
Posts: 345
Joined: Sun Feb 27, 2005 4:16 pm

#5 Post by windowmann2000 » Wed Apr 19, 2006 4:42 pm

OK hotshot your nut's. First argon usually represents about a ten dollar bill and many mfrg's just include it in the low-e package. So cost wise it's minimal. It boost the performance by over 20% and in a good glass pack should have between 70 & 80% still at ten years which well still give it close to it's original stated values.
Milgard incidently uses the intercept spacer which even rookies know is not aluminum. So your many years of experience have taught you nothing, or did you mean weeks.

tru_blue
Posts: 223
Joined: Fri Jan 13, 2006 2:02 am

Re: Leaky facts

#6 Post by tru_blue » Wed Apr 19, 2006 5:41 pm

Hotshot wrote:Milgard windows use an aluminum metal spacer that is more prone to leaking than any of the "warm edge spacers" The chances of leaking are rare in any commercially available window, but they greater in a window with a ridged aluminum spacer like the one in Milgard. I will give you my professional advise as someone who has been in the window business many years. Stay away from Milgard, and forget the argon. Argon gas will dissipate at a rate of 10% per year, and only improves the efficiency of the window by -.01 to -.03 u-factor. Such an improvement will never be visable on your gas and electric bill, and would never justify the added cost to the window.
Hotshot your statements are outrageous and reflect poorly on your knowledge of the window industry.

"Milgard windows use an aluminum metal spacer." WRONG. They have both aluminum and steel available. The Intercept steel spacer is what one would call a "warm edge" spacer. If you had bothered to check out Milgard's rated products at NFRC.org you would see this.

"Milgard windows use an aluminum metal spacer that is more prone to leaking than any of the "warm edge spacers" . . . The chances of leaking are rare in any commercially available window, but they greater in a window with a ridged aluminum spacer." WRONG. I would love to hear your "professional" explanation as to how aluminum spacers cause leaking more than steel spacers. It's how the IG unit is sealed, not the metal, that is the key variable.

"The chances of leaking are rare in any commercially available window . . ." HUH? Care to explain that? Milgard is not commercially available but all the others are?

"Argon gas will dissipate at a rate of 10% per year." WRONG. Maybe in the 1980s when non-PIB single seal IG units were made, but few manufacturers make such a poor product these days. You did say you had "been in the window business many years." It seems as if your facts are based on information from many years ago. Keep up with the changes!

" . . .improves the efficiency of the window by -.01 to -.03 u-factor." WRONG, sort of. It's pretty much .03, the high end of your range.

"Such an improvement (argon gas) will never be visable on your gas and electric bill." WRONG. It will be. Not to a great extent, but it will be. Trust me; I'm a professional.

"Such an improvement . . would never justify the added cost to the window." WRONG. It's only about $10/window more, has great benefits, and for the great majority of IG units it will be there for longer than your many years in the business.

I can only guess that you repeat what others have told you from 1982, and haven't changed much of your story since then. Welcome to these message boards, they're a great source for info, and when people post messages with info that is incorrect or misleading it will almost always get picked apart by those who know better on this board. Disagreements and the ensuing discussions can be enlightening and healthy, but hopefully those disagreements are based on facts and not fiction.

squeege73
Posts: 11
Joined: Thu Apr 20, 2006 10:02 pm

#7 Post by squeege73 » Thu Apr 20, 2006 10:29 pm

gigglebeans,

Here is what I know about argon and it is pretty simple. Most units start with about 95% argon. With the delivery system used to fill the IG units you can never get a 100% fill. The dissipation rate, depending on the unit, is somewhere between .1% and 1% per year depending on the seal of the unit. Argon usually pays for itself within 7 years with energy savings. At worst, the argon will become useless in 13-14 years with a failed unit from the argon loss. If you are still in your house after that long, a window company that has a lifetime warranty will change the unit. At that point, you will be back to a 95% argon fill. Can't see a real risk with buying argon here...

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