Argon gas is filled into a sealed unit that is located between the 2 panes of glass of a window. The gas is non-toxic and odorless. It highly benefits the homeowner because of the increase in energy efficiency. The gas also prevents frost from forming at the bottom of the glass and also gives soundproofing characteristics. The Argon-filled windows are becoming popular among many homeowners, and in some areas, are required by state law. The reason why these windows are important is that they are energy star rated and they offer better insulation due to the gas being heavier than air.