Always make sure of the percentage of argon
being used as an insulator. By federal mandate, for a company to advertise that they are using these gases as insulation they only need to have a 10% to 15% fill. And remember, these gases are DENSER than air, meaning they sink to the bottom. If you only had 10% to 15% of the insulation in your walls sitting at the bottom, you would be spending a fortune on air conditioning and heating. So don't let someone try to sell you that they have argon
insulation in their window when they are only offering the bare minimum. While it is impossible to have a 100% fill of argon or krypton, it is possible to get as much as 98% of the air between the panes to be insulation. FAS Windows
offers companies such as Wincore
that reach for this maximum, and won't settle for any federal minimums.