Some homeowners mistakenly think that the term "glaze" refers to a special coating that is put over window glass, like glazing a doughnut. However, glazing refers to glass panes themselves, so that double glazed widows actually have two glass panes side by side, with a thin coat of air or what is called argon gas between them.
Having double glazed windows installed in your home is one of the best ways of increasing your home's energy efficiency, as this added pane of glass helps to keep in your heat or air conditioning. However, not all double glazed windows are alike. Note a few things you might need to know about these windows before you shop so you can determine the best choice for your home.
Double glazing and security glass
Double glazed windows are not the same as security glass in the windows. Security glass is made of tempered glass that is denser and thicker than standard glass, so it withstands impact more readily than standard window glass.
Even with security glass, the level of security it offers will vary; some resist the impact of strong storms and high winds, while others might withstand a rock thrown at them. If you're concerned about your home's security, don't assume that double glazed windows themselves will offer this added level of security, as both those panes of glass might be somewhat thin if you choose the cheapest type available. Be sure you opt for security glass that will be withstand whatever damage you think a window might suffer.
While double glazed windows are typically better than single paned windows when it comes to insulating your home and saving you money, here too you need to consider additional features that maximize your investment. For example, the term U value refers to how well something transfers heat, so glass with a very low U value will keep heat out during long, hot summers and then also keep heat in when you have your furnace running in the wintertime.
Low-E glass refers to glass that has metallic elements added to its mixture when it's made to reflect heat or cold back into a room or back outside, not allowing that heat or cold to pass through. This type of glass usually offers the best insulation for your home while still allowing maximum sunlight to pass through. If you want a bright room but want to reduce the heat in the home from sunlight during summer, Low-E glass is the best.