Gas: Argon and Krypton in your windows...Post Source: http://www.replacement-windows.com/windowbb/viewtopic.php?t=497
Argon and krypton are both inert gasses as are helium, neon, xenon, and radon. All of these are naturally occuring and are elements listed on the Period Table while freon, on the other hand, is a chlorofluorocarbon or man-made gas.
Helium is lighter than air while the rest of the inert gasses are heavier than air.
Dry air has a density of 1.29 g/cm^3 at sea level.
Helium at .18 gm/cm^3 and neon at .9 gm/cm^3 are both less dense than air.
Argon at 1.78, krypton at 3.75, xenon at 5.9, and radon at 9.73 gm/cm^3 are all denser than air; but it occurs to me that if a manufacturer brags that he uses radon gas as his window infill he might be risking possible marketing problems so I have my doubts that we will ever see radon as an IGU infill.
Anyway, argon, krypton, and xenon can all be used as an IGU infill with various degrees of success.
The width of the airspace in the IGU has a great deal of influence on the performance of the inert gas versus air.
As a general rule, an IGU with air infill reaches its optimum energy perfomance at about 1/2". This is also close to where an IGU with an argon infill reaches its peak performance. The energy perfomance of the unit will then begin to gradually drop off as the airspace gets wider, no matter if it is filled with air or argon.
An IGU with a xenon infill reaches its peak energy numbers at about 3/16" and then begins to gradually drop off in performance.
An IGU with krypton reaches its peak at about 5/16" and then begins to gradually decline as well.
At 1/2", when argon is at its peak, krypton performance is still slightly better than argon and xenon is still slightly better than krypton. But, the increase in cost will not offset the slight advantage in performance of either krypton or xenon versus argon...so, if the IGU airspace is 7/16" and greater, then argon is the best value. Below that, then it will depend on what the manufacturer is offering.
If you are buying a triple pane or a dual pane with IGU spacing of 1/4" or so then krypton is definitely an option for the greatly improved performance at those spaces. Also at these narrower spacings a mixture of 25% argon to 75% krypton is very close in perfomance to pure krypton at (presumably) a bit less cost.
Curiously, at 7/8", the difference in performance between air and argon is more than is the difference in performance between argon and either krypton or even xenon.
VA, your Schuco dealer was absolutely correct. Many window companies do fill their IGU's like you would fill a bottle with water. They leave a little hole in the top of the IGU and "pour" the gas in since all of the gasses used for insulating value are heavier than air and will displace the air in the unit until it is "full".
As Dean mentioned, some folks will use two holes, one to suck the air out and one to fill the argon.
And some, Cardinal and Schuco immediately come to mind (which is easy since they were mentioned previously), use a sealed vacuum chamber where the air is totally exhausted and replaced by the gas and then the IGU is sealed while still within the chamber.
Hope this all made sense and that it helps a bit!
Post Source: What's the difference between Argon and Krypton gas?
Posted: Sat Mar 26, 2005 8:24 pm