Part 1 : Engineers Give Pros and Cons of Double and Triple Pane Windows

ave you decided to invest in replacement windows? What made you finally decide to take the leap? Was it the incredible energy saving benefits new windows offer? If so, you’re not alone. For a typical home, 40% of the annual energy budget goes toward heating and cooling costs, and replacing the windows in your home is great way to keep more of that money in your pocket.

Since energy efficiency is such an important fact to consider when getting replacement windows, we are often asked, “How much better are triple pane windows than double pane windows at saving money on energy bills?” This is a great question, and definitely an important question to address. But, deciding between these two window types isn’t as easy as calculating cost to efficiency. Here’s what you need to know.

Engineers Know Why Double Pane Windows are Best

If you break down the math, double pane windows are the best bang for the buck. This is probably why it is the number one window choice in the entire country. When you upgrade your current windows to double pane windows, you’re going to notice the difference. A standard double pane window with argon gas is going to reflect 90% of the energy and only let 10% through. That means on a sunny day, 90% of the heat from the sun is going to stay outside, and only 10% is going to get in. On a cold winter day, 90% of the heat from your furnace is going to stay inside your home and only 10% is going to leak out. In comparison, a typical triple pane window will reflect 97% of energy and only allow 3% to pass through. Since triple pane windows can cost ⅓ more than double pane windows, it makes sense to go with double pane windows if you’re looking for the best deal up front.

Do you like natural light? When you have two panes of glass instead of three, you’re going to have fewer coatings for the sun to get through. That means double pane windows will allow more light into your home. It is a subtle difference, but one to consider.

Engineers Develop Triple Pane Windows

Folks who chose triple pane glass windows choose them for the comfort. If you measure the temperature on the inside glass of a double pane window and a triple pane window on a cold winter day, the interior glass of the double pane window is going to be cooler. For this reason, homes that have all triple glass windows are cozier. Triple pane windows are within a degree or two of the wall temperature at any given time. This creates a high level of occupant comfort and reduces convection currents and drafts. If comfort is your biggest concern, triple pane windows will be the best option.

A reduction in energy bills isn’t the only reason customers choose triple pane glass. Some of our customers are also looking for a reduction in noise. The extra pane of glass makes this window option the number one choice for keeping noise out. If you have noisy neighbors or live near a busy street, triple pane windows can really make a difference.

If noise reduction appeals to you, there is a good chance you’re in a city. That means you’re likely to prefer triple pane glass for the extra security as well. The glass we use has the same technology used in windshield design and can withstand up to 30 swings from a baseball bat.

Getting New Windows is a Big Improvement

You’re going to immediately benefit from getting replacement windows no matter what glass option you choose. Window technologies have come a long way, and having windows that make a good seal is just as important as getting modern ENERGY STAR efficiency.

Triple pane windows are an exclusive step up from double glazed windows. With three panes of glass and two spacers instead of one, triple pane windows become much heavier than double pane windows, however if fiberglass is used for frame material, it is able to withstand the weight of a triple-glazed window. Having double pane windows can help the condensation problem, but even they remain cooler than the air inside the home. Poorly insulated windows allow heat near them to escape, which makes them cool like the exterior is. Triple pane windows are more likely to maintain this warmer temperature of the window’s surface.

Double Pane Windows-Pros and Cons

Double glazing windows consist of two panes of glass with a spacer that separate them. It is required as a standard for all residential applications in Canada due to the harsher climate during the winter. Double pane windows can reduce up to 50% in heat loss, keeping your energy bills at a lower rate and in combination with a fiberglass frame, the overall energy efficiency of your fiberglass windows increase. The main benefit of double pane windows is the cost factor. The cost difference between double pane and triple pane fiberglass windows may vary. At Fibertec, the difference between the dual vs triple pane is approximately 15% while most companies reach about a 40% cost difference.

Frame Material
PROS AND CONS: When looking for an energy efficient window, the frame material plays a big role in determining the quality of the window. With a double pane window, fiberglass frames are the best choice because it is designed in such a way that the closed back frame (not all companies offer closed back frame) can support a double glazed window without warping. Double glazed fiberglass windows may cost more up front, however over time you will be saving money.

Spacer Used
PROS AND CONS:With double glazed fiberglass windows, one spacer is used to separate the panes of glass. The space left between the two panes must be correct in order to achieve proper air flow between the panes of glass. Exceeding or not achieving the right space between a double glazed window can have a great effect on the energy efficiency of the window.

Gas Fills
PROS AND CONS:Double pane fiberglass windows can have a gas fill between the panes of glass for added thermal efficiency. Gases such as argon gas and krypton gas can be used as an insulator. Argon gas is often seen as a more popular choice because it is also significantly lower in price than krypton gas and is, in most cases, a more suitable gas to use for insulating fiberglass windows.

PROS AND CONS:Dual glass panes perform much better than one single pane of glass, not only because of the space between the glass. The glass itself can act as an insulator as well. By using Low-E coating on the glass, infrared light is kept out while allowing visible light to enter your home. Heat mirror film is also used in combination with double glazing fiberglass windows for added insulation.

Triple Pane Windows-Pros and Cons

Triple pane windows are an exclusive step up from double glazed windows. With three panes of glass and two spacers instead of one, triple pane windows become much heavier than double pane windows, however if fiberglass is used for frame material, it is able to withstand the weight of a triple glazed window. Despite the weight of a triple pane window, there will be no effect on the everyday use of your windows. The reason why people are much more attracted to choosing triple pane windows is because there is a great difference in performance between a double and triple pane window. When comparing factors such as the SHGC, or U-values, there is an approximate improvement of 20-30% in a triple pane window’s energy ratings. In most cases, companies will upcharge triple glazed windows due to the fact that other companies use a double pane frame and try to put a heavier triple pane unit inside the same frame design and try dissuade customers from using triple pane units by increasing the pricing.

Frame Material
As mentioned before, triple glazed windows are much heavier than double glazed windows and need a strong frame material that can be durable enough to last. Due to the properties of fiberglass, fiberglass frames are able to withstand heavy loads without twisting, warping or sagging overtime.

Spacer Used
Triple pane windows have two spacers that separate the panes of glass in a triple pane fiberglass window. Using a spacer is made from a superior quality silicone resistant to UV light oxidation and offers great argon gas retention for higher energy efficiency.

The same gas fills used in double pane windows are used in the same way for triple pane fiberglass windows. The only difference is that triple pane fiberglass windows have gas injected into both air fill spaces between the panes of glass, significantly increasing the energy efficiency of a triple glazed fiberglass window.

Glass Used
Triple glazed fiberglass windows have three panes of glass. Two of three layers of a soft/hard coat low-emissivity (Low-E) film can be added on the non-exposed surfaces of the glass (one per chamber). By having three layers of glass, your windows are able to reduce outdoor noise transmitting through the windows.


2 thoughts on “Part 1 : Engineers Give Pros and Cons of Double and Triple Pane Windows”

  1. It’s cool that double-pane windows will be able to withstand harsher climates. My boss wants to build a machine that drops that temperature of the surrounding area, and he wants to make sure that it can be viewed in safety. I’ll share this information with him so that he can look further into his options for getting double-pane windows for it in the future.

    1. Best of luck with your project. Are you considering triple pane windows? Some of the new zero energy buildings are seriously contemplating that as a solution.

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