Glass Glossary

Argon Gas


Last Updated: December 4, 2023

Argon gas is a colorless, odorless, non-toxic, and inert gas that is commonly used as a fill between the panes of insulating glass (IG) units. It is a naturally occurring gas, making up about 1% of the Earth’s atmosphere, and is typically harvested as a by-product of oxygen and nitrogen production.

Figure: Argon element diagram

In the context of insulating glass, argon gas is favored for its low thermal conductivity, which slightly enhances the insulating properties of the IG unit. The low conductivity of argon gas reduces the transfer of heat through the window, helping to maintain a more consistent and comfortable indoor temperature, and improving the energy efficiency of the window.

Compared to air-filled IG units, argon gas-filled units provide better insulation and energy performance. Air contains moisture, which can cause condensation and reduce the clarity of the window over time. Argon gas, being drier than air, can help mitigate these issues. Additionally, since argon gas is heavier than air, it reduces the convective movement of air within the space between the panes, further improving insulation.