If you’re looking for methods to improve the energy efficiency of your house, you’ve probably stumbled upon the term gas-filled windows, right? So, what are these?
In short, they are Insulated Glass Units comprising two or more glass panes separated by gas fills. This improves insulation, reduces heat transfer, limits outside noise, and lowers energy bills.
If you want to discover more, read on! We’ll share details about different types of gas used for windows and their properties.
Key Takeaways
- Gas-filled windows are Insulated Glass Units. They have two or more glass panes separated by a gap filled with an inert gas, which improves the window’s thermal efficiency.
- Windows filled with gas are more energy-efficient than single-pane or air-filled windows. They also have soundproofing abilities.
- There are three main types of gas used in the window industry – argon, krypton, and xenon. Argon gas windows are the cheapest but also the least energy-efficient when compared to krypton and xenon gas windows. Nonetheless, they are an excellent choice for home insulation.
What Are Gas-Filled Windows?
Gas-filled windows have two, three, or (rarely) four glass panes, which form a single-window system, commonly known as an Insulated Glass Unit (IGU).
We can trace the roots of this design back to the 19th century, when homeowners in Europe added a second pane of glass to existing windows, trying to keep their homes warm in winter. However, the concept of having two glass panes within the same frame developed only in the 1930s.
Unfortunately, window manufacturers stopped working on this project during World War II, which is why double-pane windows started being installed in European and American homes only in the 1970s. Since then, window manufacturers have improved window energy efficiency by separating the glass panes with air or inert gases.
These windows have dramatically improved thermal performance by minimizing heat transfer, which translates into significantly better energy efficiency and lower energy bills – a delight for homeowners living in regions with extreme climates! Additionally, gases like argon provide superior noise reduction compared to air-filled windows, creating a quieter indoor environment.
Typically, the space between the glass panes that is filled with gas is 1/2 – 3/4 of an inch wide. At Magic, however, we’ve extended this gap to a full inch, so we can add 25%-50% more gas. This means that our windows feature superior insulation compared to other products on the market. If you want to learn more about them, book a free consultation today! In the meantime, let’s discover the types of gases used in the window industry.
Types of Gases Used in Windows
Energy-efficient windows are usually manufactured using three types of noble gases: argon, krypton, and xenon. Since krypton and xenon are more expensive, argon takes the lead in the industry.
Each of these gases has unique properties that contribute to a window’s insulation performance. Keep reading to discover more about each!
Argon Gas
Argon gas is a naturally occurring element in the Earth’s atmosphere, comprising almost 10% of it and being the third most abundant gas. It is colorless, odorless, and tasteless, and it is also non-toxic. Since the thermal conductivity of argon is 67% that of air and since argon is six times more dense than air, it is an excellent alternative for air-filled windows. Argon insulates much better, and the price difference isn’t too noticeable – no wonder argon has been the most commonly used gas in window manufacturing since the 1980s.
Argon gas fills help improve thermal insulation by reducing heat gain in the summer and maintaining warmth in the winter. When combined with low-E glass coatings, argon gas can bring window temperatures closer to room temperature, eliminating drafts effectively and enhancing overall comfort.
Krypton Gas
Krypton gas is another naturally occurring gas that is odorless and colorless. Krypton is twelve times more dense than air, so it acts twice as good as argon as an insulator. However, krypton is also much more expensive than argon gas. Studies have shown that windows with krypton gas are approximately 40% more expensive than argon gas-filled windows. This can be attributed to the fact that argon is much more common in the Earth’s atmosphere, whereas krypton is only found in trace amounts.
Krypton gas is usually used in triple-paned windows with thin gaps, usually between 1/4 and 3/8 of an inch. In gaps wider than this, convection currents can form and, therefore, the window insulation may be compromised.
In addition, krypton gas windows may also be used in older buildings with insufficient room for thicker windows filled with argon.
Xenon Gas
Xenon gas, also a colorless and odorless noble gas, is, like krypton, found only in trace amounts in the Earth’s atmosphere. It offers the highest degree of insulation, but given that it costs incredibly more than both argon and krypton, it is only rarely used in the window industry. Xenon gas windows are usually only approved for structures with extensive glazing – skyscrapers, for example.
Benefits of Gas-Filled Windows
Here are the benefits of installing gas-filled IGUs:
- Energy efficiency. IGUs are a game-changer when it comes to window energy efficiency. These windows can significantly lower heating and cooling expenses, resulting in substantial energy savings. Using argon gas instead of air can enhance the insulating value of windows by up to 16%, while using krypton gas improves insulation by up to 27%.
- Noise reduction. One of the often-overlooked benefits of gas-filled IGUs is their ability to reduce noise pollution. An argon-filled window provides better sound insulation than a standard air-filled window or a single-pane window, thanks to the gas that improves sound-dampening properties. This results in a quieter, more relaxing indoor environment and better sleep.
- UV protection. IGUs filled with inert gas and equipped with Low-E coatings can offer significant protection against harmful UV rays. This can prevent your furnishings from being damaged, thus helping you save money on repairs and replacements.
- Less condensation. Windows filled with gas are much more resistant to condensation than air-filled windows. This reduces the risk of mold growth, frame damage, and corrosion.
Potential Drawbacks of Gas-Filled Windows
While windows filled with gas offer numerous benefits, they are not without potential drawbacks.
The first and most important one is, of course, the cost. IGUs filled with gas are more expensive than IGUs filled with air. However, if this is a concern, just go with argon gas double-paned windows – they’re cheaper than windows filled with krypton and not much more expensive than air-filled windows. The investment is definitely worth it in the long run, as you’ll spend less on energy bills, and your windows will have a longer lifespan.
Another thing to consider is that the gas from between the glass panes can leak over time. Leaks might take years to significantly affect performance, but they do occur, with potential gas loss of up to 1% annually. As argon gas escapes, moisture-laden air enters the window to replace it, and the insulation effectiveness decreases, potentially leading to higher energy bills. Nonetheless, even if these leaks occur, the gas fill efficiency will still be at 80% after 20 years unless the seal is broken or the frame is severely damaged, which can increase the amount of gas that escapes the IGU.
Fog or frost between window panes can indicate gas leakage, and it is a clear sign that the insulation is compromised.
Longevity and Maintenance of Gas Filled Windows
Argon gas windows can maintain their effectiveness for 20 years if they retain at least 80% of the argon gas. However, Magic windows can last up to 40 years because we add 25%-50% more gas within our IGUs, which improves their insulation and extends their lifespan.
However, this lifespan can only be achieved if the windows are properly installed. Otherwise, they will leak in no time and will likely need to be replaced much sooner than 20-40 years.
It’s also important to note that the longevity of your windows depends on the climate and the window frame material – not all materials can withstand harsh weather conditions, and if the frame is damaged, so is the IGU.
Other factors that influence a window’s lifespan are:
- The quality of warm edge spaces, which insulate the edges of an IGU, keeping the glass panes apart. They have to expand and contract at the same rate as the glass unit; otherwise, the gas will escape at a much higher rate, and the seal will break.
- Whether the window has any Low-E coatings
- Regular maintenance and addressing any issues as soon as possible.
How to Check the Energy Efficiency of Gas-Filled Windows?
If you’re planning to buy windows filled with gas, you should look for the following energy ratings, which assess how energy-efficient the windows are:
- U-factor, which indicates the heat transfer rate of a window; lower numbers are better.
- Solar Heat Gain Coefficient, which indicates how much solar heat passes through a window; you should look for higher numbers in cold climates and lower numbers in warm climates.
- Visible Transmittance, which indicates how much natural light passes through a window; higher numbers are better.
- Air Leakage, showing how resistant a window is to air leakage; lower numbers are better.
If the windows you’re planning to buy have Low-E coatings, this is a good thing, as these coatings can significantly improve their energy efficiency.
The energy ratings mentioned above can be checked on the NFRC label. In addition, if the windows have an ENERGY STAR label, you can rest assured they’ll insulate your home well. These labels certify that the windows meet strict energy efficiency standards.
Can’t Decide Which Windows Are the Best for You? Book a Consultation with Magic!
If you still can’t decide which windows are the best for your home, one of our project managers can help you make the right decision. They will assess the climate in your region, the design particularities of your home, as well as your preferences and budget, and provide you with a solution that is fully tailored to your needs. Given that we’ve brought glass production in-house, there’s no window replacement project we can’t accommodate!
Frequently Asked Questions
Are gas-filled windows worth it?
Gas-filled windows are definitely worth it, as they’re more energy-efficient than single-pane windows or windows filled with air, which can help you save money on energy bills. They also have a longer lifespan, offer UV protection, and have soundproofing abilities.
How can you tell if a window is filled with gas?
Windows are filled with gas if they have two small holes along the spacer – gas enters through one of them, and air exits from the other.
How long do gas-filled windows last?
Windows filled with gas last approximately 20 years, although some windows, like Magic’s, are manufactured using more gas fills and materials of the highest quality, so they come with a 40-year warranty.
What are the cons of argon gas windows?
Argon gas windows are more expensive than air-filled windows or single-pane windows. They can also leak over time. Also, argon is not the most energy-efficient gas on the market – krypton and xenon are better insulators.
Can gas-filled windows be refilled?
In some cases, windows can be refilled with gas as long as the seals can also be replaced.
Should argon-filled windows fog up?
Condensation or fogging between the window panes is a clear sign of gas leakage, suggesting a compromised seal. It’s best to address this issue promptly to prevent further damage and maintain energy efficiency.