Choosing the Right Window Glass will Save You Money Choosing the Right Window Glass will Save You Money

In frontier days people used to put a piece of waxed paper into an opening in the wall of their cabin to let in some natural light. Now a piece of paper has  some obvious disadvantages such as you can't see through, it has no insulating value and cold and heat can easily move through it, so it wasn't used for long. Nowadays, window glazing technology has progressed well beyond the wax paper stage and choosing the proper window glass for your home windows will let lots of light in, allow you to see out and even save you money and energy. Here's an overview of some of the features of modern glass windows.

Double and triple panes

  • Single pane glass windows are no longer available and modern windows have double or triple panes of glass with air trapped between the panes. Air is a good insulator so having an air gap helps minimize heat transfer from through the window (and also helps block noise). In addition to minimizing heat loss, a warmer window on the inside means less condensation forms on the inside window, so there is less potential damage to inside window frames.

Argon filled glass

  • Rather that simply leaving an air gap between glass panels, inserting an inert gas (Argon is most common but Krypton and other naturally occurring harmless gases are also used) provides an increase in the insulating value of the window. Gases like Argon are6 to 12 times heavier than air, so provide a denser atmosphere that is more resistant to heat transfer.
  • Argon and krypton filled window are particularly effective at colder temperatures so in a colder climate gas filled windows will provide a greater benefit than in warmer areas.

Low E coating

  • Although gas filled windows improve the insulating value of a window they don't block the transmission of either infrared radiation or harmful UV rays so your carpets and furniture will be subject to fading.
  • Low E glass (also called solar low E or "spectrally selective glass" ) has been covered with a very thin metallic coating that makes it "low emissivity" meaning it reflects light back from the surface thus reducing UV rays in your home as well as keeping heat in during the winter and out in the summer.
  • There are tow types of lowE coating available. - Hard coat lowE and soft coat lowE. Hard coat is the older technique and is less expensive than soft coat, however in addition to being reflective soft coat lowE also provides a small level of insulation to the glass that hard coat does not.


  • Spacers separate and maintain the "air gap" between the glass panels so they are actually touching glass. Aluminum (metal) spacers used to be standard however, less conductive materials are now more common in well built windows.
  • Structural foam is the ideal material for spacers since it resists heat transfer and also moves as the glass expands and contracts during heating and cooling.
  • Low conductivity spacers can improve the performance of gas filled, lowE filled windows by as much as 20%.

Murray Anderson is an experienced freelance writer whose work has appeared on numerous web sites, as well as in newspapers and books in both the US and Canada. He is often cited as an expert on home related topics.

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