Let's Talk Glass: IGUs

If you’re thinking about replacing your windows, you’ve probably run across the term “IGU” in your research. This acronym stands for insulated glass units, which refers to double and triple-pane windows. Could IGUs be right for your upcoming window replacement? Learn more about them to find out.

What Are Insulated Glass Units?

Windows with multiple panes of glass are separated by a spacer and sealed together along the edges. A desiccant is used to remove humidity from between the panes as they’re sealed together to prevent condensation from building up.

Window pane thickness typically ranges from 1/8 inch to 3/8 inch. Most IGUs are manufactured with the same thickness for both panes of glass. We here at Glass Doctor® have to show off our industry expert, nerdy side for a moment: A common misconception is that IGU glass is tempered or laminated for safety, when in fact, the glass is typically annealed. Meanwhile, the use of tempered safety glass is governed by the building codes. Most common uses of tempered or safety laminated glass is in doors and windows near walking surfaces.

Why Are IGUs Filled With Insulating Gas?

Glass is a poor insulator, so it’s not the extra thickness that gives IGUs greater insulating power – instead it’s the ½ inch airspace between the panes that makes them efficient. In some insulating glass units, the space is filled with nothing but air. However, in high-end windows, a clear, non-toxic gas such as argon, krypton or xenon is used.

These noble gases are denser than air and conduct heat less readily. Argon is used most commonly used, but krypton and xenon are more efficient – not to mention considerably more expensive.

In order to prevent insulating gas from leaking out and moisture from getting in, it’s important to choose a quality window with intentional design. Look for the presence of warm-edge spacers, which not only reduce conducted heat loss through the edge of the window, but also improve the retention of insulating gas. This is important to maintain high window efficiency for many years after installation.

How Are IGUs Used?

With their customizable shapes, sizes and thicknesses, insulating glass units are appropriate for everything from industrial to commercial to residential applications. With the addition of a Low-E coating, IGUs improve their U-value, or the ability to slow heat transfer through the glass. The lower a window’s U-value, the better insulating ability it has.

Benefits of IGUs

It’s true that insulated glass units cost more than single-pane windows. You might be wondering if the additional cost is worth it. Even if you live in a climate where the temperature outside is perfect all year-round, you’ll still appreciate the benefits of IGUs:

  • Lower heating and cooling bills: This benefits most homeowners who dread paying for heat in the winter and air conditioning in the summer. Heightened thermal performance means outdoor air temperature has a lower impact on indoor conditions, allowing you to run the furnace and air conditioner less.
  • Increased comfort: If everyone avoids sitting close to the living room window because it gets so drafty in the winter, you understand how low-performance windows can impact indoor comfort. With less air leakage through insulated windows, your entire house feels more comfortable.
  • Reduced sound transmission: Anyone who lives in an urban area or near a busy street can attest to the importance of noise insulation. Regardless of the climate, the ability to close the window and block out sound from outside is a great benefit.
  • Increase window strength: You want your windows to last, even if gale-force winds beat on the side of your house. IGUs are stronger than single-pane windows and are able to withstand higher wind loads.

Glass Doctor has many specialties, one of which is replacing damaged windows in homes and businesses with insulated glass units. Depending on the damage, you may be able to keep the frame and just replace the glass. To learn more, please contact Glass Doctor today.