What is argon and can it really escape from inside the sealed airspace?
Argon is a non-toxic heavier-than-air gas that can be used to fill the airspace in between the sheets of glass to enhance energy efficiency and reduce sound transmission. Argon in the airspace DOES NOT increase the chance of fogging inside the airspace or failure of the insulated glass seal. Since the argon doesnt move inside the airspace as much as everyday air like you and I breathe (which is all that most windows have inside the airspace) there is not as much heat and cold transfer taking place through convection. The U-value of the window is improved approximately 10% when argon is added. The window industry view seems to be that you may lose about 1% of the argon fill per year, so with a typical 90% argon fill, in 20 years you may only have 70% argon in the airspace, reducing the added energy savings slightly. This DOES NOT increase the chance of a seal failure or clouding up of the sealed airspace.
