Good afternoon friends!
Today we’re going to look at windows. There’s a lot of jargon in the window industry. Low-E, argon, solar heat gain coefficient, u-value/r-value, fenestration (that was just showing off). It is a daunting aspect of the home build selection process. Most home owners don’t even care, they just request colours, brickmoulds and accessories like grilles. I hope this primer can be a window into the world of fenestration (fenestration refers to all openings in the building envelope for doors/windows).
Here’s a quick overview of some important terms:
- Low-E: This is a Low Emissive coating on the window. The basic purpose of low-e coating is to reflect UV rays and other heat rays. This means you’ll get less solar-heat-gain. Which leads us to…
- Solar-heat-gain coefficient (SHGC): This will be a number between 0 and 1 you’ll find on your window. The higher the number the more heat from solar radiation you’ll allow into your house.
- Argon gas: Argon gas is denser than air. For this reason it is often used to be the insulating layer between panes of glass. It has a lower thermal conductivity than air so will wind up insulating your window better.
- U-Value/R-Value. These are two different ways to measure the insulating qualities. U-Value refers to the window as an entire unit, whereas R-Value is used more for individual components. The lower the U-Value, the better the insulator, which is opposite for R-value.
So in general you’ll use windows with a lower SHGC on the south and west side of your house to avoid overheating your home in summer time. On the north side you’ll want to have well insulated windows as it won’t see much sun light in winter. This general rule of thumb shouldn’t trump the advice of a building scientist who will do advanced heat loss calculations to determine exactly what coating you want on which windows.
When selecting windows, we at Dueck Homes, believe it’s very important to go to triple pane. When you’re building a custom home here in Winnipeg, the difference between dual pane and triple pane windows is very noticeable! You’ll notice walking by your dual pane windows in winter that the air is cooler, not so with triple pane. Triple pane windows will help avoid overheating in summer, cooling off in winter, condensation in winter months and drastically reduce noise levels. For this reason we highly recommend triple pane windows.
If you have questions on replacing the existing windows in your house, or about building a new house, please come talk to us! We’d love to help!