The wrong window glazing could easily undermine all your energy-saving efforts, driving up your home’s annual heating and cooling costs.

Double or Triple-glazed Windows – What Works Best?

Homeowners are beginning to realize the importance of insulated glazing for their windows. The aim of insulating your glass or windows is simply to prevent significant heat transfer into or out of a building. This is done by combining multiple panes of glass in a single-window unit and filling the spaces between the panes with air or inert gas. The most common types of glazed windows are double glazed and triple glazed units.

A double-glazed glass has two panes of glass separated by a cavity filled with air or inert gas. On the other hand, a triple-glazed glass has three panes of glass and two air or gas-filled cavities. According to Ecoline, Canadian window replacement experts, insulated glass units do not just stop at heat transfer, they also offer reduced noise transmission, UV protection, and even extra security.

Now the main question is, should you buy a double or triple glazed glass unit? Whichever option you choose will boil down to your preference, cost implications, and energy efficiency. The extra pane of glass provided in triple glazed window units improves energy efficiency as it performs better than double glazed glass units in terms of its U-value. The U-value is an industry standard for measuring the energy-conserving performance of windows, and the lower the value, the more efficient the window is.

Most of the time, we get asked whether the difference in performance between the double and triple glazed glass is commensurate with the difference in prices. Well, Ecoline experts claim that triple-glazed windows are approximately 15% more expensive than their double-pane counterparts but provide up to 50% more energy efficiency to homeowners.

Should I Go for an Air or Inert Gas Window Filling?

If you have been following the conversation from above, this would be an excellent question to ask next. You should definitely buy a window unit with an inert gas filling, and we’ll tell you why. Air insulates less effectively than inert gas fillings. You would also find that the spaces can become cloudy due to the condensation of the moisture-containing air.

On the other hand, inert gases perform significantly better and lower the U factor of your window unit. Additional benefits come as follows:

  • Inert gases also improve the soundproofing character of your windows 
  • They will not corrode the window material the way oxygen will.
  • It’s also important to note that these gases are non-toxic, non-reactive and odourless. 

The most commonly used inert gas filling are Argon and Krypton. Argon is more cost-effective than Krypton and is more widely used, especially in double-glazed windows. Krypton is more frequently used in triple-glazed glass because it takes up less space and has a lower U value rating.

Low-E vs. Tempered glass – What to Choose?

Low emissivity and tempered glass are the most common glass options when it comes to strength, energy efficiency, and appearance. Low-E glass is glass coated with a thin layer of metal during its manufacturing process to reduce the heat transfer rate through the glass. This special coating reflects heat but still allows light to pass through. There are different types of coating, such as the high solar gain coating and low solar gain coating.

High solar gain Low-E glass coating is best suited for buildings in hotter climates, while Low solar gain Low-E glass coatings can work for both warmer and cooler climates because of their ability to reduce solar heat gain while retaining a high transmittance of visible light. High solar gain low- E glass, on the other hand, reduces heat loss but admits solar gain.

Tempered glass is commonly called safety glass as it is 4 times stronger than untreated glass. When tempered glass breaks, it is designed to crumble into small, dull-edged pieces, unlike untreated glass, which breaks into dangerous shards under comparatively little force. Because of the reduced risk of injury that tempered glass poses, it is often used as a safety glass. In Canada, there are specific Safety Glass Regulations to follow.

The Bottom Line

When installing new windows or replacing old ones, people tend to focus on things like frames, window styles, and glazing units, neglecting the choice of glass for your window unit. It is as important as any other factor, especially if energy efficiency is a big deal for you.