What Is Argon Gas and Why Is It In Windows?

Are you looking to update your home’s windows for better insulation and energy efficiency but need clarification on the role of argon gas? Many homeowners need to know what it is and why their windows may be filled with this gas. Argon gas has been used in double or triple-paned insulated glass units since the 1990s because of its superior insulating capabilities compared to air. This blog post will explain argon gas and highlight why you want it in your new replacement windows.

This article covers the following topics:

  • What is argon gas?
  • What does it do in replacement windows?
  • Does argon gas make windows more efficient?
  • How is argon captured for use in home windows?
  • How long does argon gas last in windows?
  • How full of argon should windows be?
  • Can you buy windows with just argon gas?

What is argon gas?

argon gas in between glass panesargon gas between three window panes

Argon is a colorless, odorless, tasteless, non-toxic, and chemically inactive noble gas. It is the third-most abundant gas in the Earth’s atmosphere, making up approximately 1% of our air. Argon is used in various industrial applications, such as filling incandescent and fluorescent light bulbs, and as an inert shielding gas in welding and other high-temperature operations. It is also used in between glass panes of energy-efficient windows.


What does it do in replacement windows?

Argon gas is often used as a filling gas in energy-efficient windows. When sealed between two panes of glass in a double-paned or triple-paned window, the argon gas helps to reduce heat transfer through the window. This can improve the overall insulation value of the window, making it more energy-efficient. The argon molecules’ slow movement helps prevent heat from escaping the home in the winter and entering the home in the summer, leading to more consistent indoor temperatures and potentially lower energy bills. Additionally, the use of argon gas in windows can improve their acoustic insulation, reducing the amount of outside noise entering the home.


Does argon gas make windows more efficient?

Yes. Argon gas lowers the U-factor in windows. The U-factor, also known as the U-value, measures the heat transfer coefficient in windows and other building components. It is used to quantify how well a material or component insulates, with lower U-factors indicating better insulation. The U-factor is expressed in watts per square meter per kelvin (W/m²K). It represents the heat transfer rate through a material or component, considering its thermal conductivity, density, and other thermal properties. When choosing windows, a lower U-factor is generally preferred, as it indicates that the window will have a better insulating value, helping to reduce heat loss and improve energy efficiency in the home. Click here to read more about NFRC ratings for energy-efficient windows.


How is argon captured for use in home windows?

Argon is sourced from the air we breathe. It is the third-most abundant gas in the Earth’s atmosphere, making up approximately 1% of the air. The air is first compressed to extract argon and then cooled to separate the other gases. The cooled air is then passed through fractional distillation, where the gases are separated based on their boiling points. During this process, argon is collected and condensed into a liquid form, which can then be stored in containers. Producing and purifying argon is typically performed by specialized companies that supply the gas to various industrial and commercial customers.


How long does argon gas last in windows?

Argon gas in windows can last for the window’s life, typically around 20-30 years. The sealed units of double-paned or triple-paned windows are designed to be airtight, so the argon gas should not leak out over time. However, if the seals around the edges of the windows are damaged, argon gas can escape, reducing the window’s insulating value. In this case, the window may need to be repaired or replaced to restore its energy-saving benefits. Regular maintenance, such as cleaning the windows and checking the seals, can help extend the argon gas life in windows.


How full should the windows be?

Most glass manufacturers find that 100% fill is impossible, so they target 90%.


Can you buy windows with argon but without Low-E?

According to Cardinal Glass, it is not recommended. “Cardinal IG does not recommend using argon in units without a LoĒ coating. Adding argon gas provides only a small improvement in U-Factor compared to adding a LoĒ coating. In the absence of a LoĒ coating, the argon gas will only provide a small incremental improvement in UFactor and no effects on Visible Light Transmission (VLT) and Solar Heat Gain Coefficient (SHGC) values.”


In closing

Argon gas is an essential factor to consider when looking for energy-efficient windows. Our article was created to make choosing replacement windows that will be right for your home easier. If you live in the Dallas-Fort Worth area, we would love to help you choose the right windows for your home. Give us a call or come by our showroom, and one of our knowledgeable team members will assist you in finding the perfect windows for your needs.


Additional argon gas resources

“Element information, properties and uses | Periodic Table” by the Royal Society of Chemistry (rsc.org)
“Properties, Uses, and Occurrence” by AZoMining (azom.com)
“Argon: The Complete Guide” by Compressed Gas Association (cganet.com)
“Argon – Physical and Chemical Properties” by Lenntech (lenntech.com)