One of the biggest benefits of getting replacement windows is the increased energy efficiency the new windows bring. That’s great for not only the environment, since you use less resources such as natural gas for heat and electricity for air conditioning – it’s also great for your home energy bill!
But you’ll also want to pick the right window for your home to match the type of climate you live in. Depending on the climate, you may want to choose a different glaze or insulation.
We’ll start with some general guidelines, and then discuss specific made-in-Canada climate considerations for windows.
In hot climates, keeping your home cool and keeping heat from transferring from the outside to the inside is key. One term to keep in mind is the window’s Solar Heat Gain Coefficient. This commonly refers to how much energy a window transfers, including all components such as the glass, frame and sash. SHGC values range from 0 to 1. The lower the value, the less solar heat gain.
So, in hot climates, look for windows with a lower solar heat gain number. Also consider windows glazed with tinted glass to cut down on how much heat gets in your home.
In cold climates, the no. 1 thing to keep in mind is preventing heat loss from your home. This is tracked with what’s called a window’s U-factor, a rating system set up by a national council of window makers. The U-factor generally ranges from 0.25 to 1.25. The lower the U number, the less the heat transfer. For colder climates, try to keep the U-factor under or equal to 0.30. Also, consider windows that are double-glazed or have insulated glass units.
In mixed climates you are dealing with both hot and cold, making it somewhat more of a challenge to keep your home comfortable. Keep your eye on the Solar Heat Gain Coefficient, which should be between 0.35 and 0.40. Meanwhile, the U-factor should be less than or equal to 0.32 to ensure maximum comfort.
Energy Star windows in Canada come in four different standards, depending on the climate zone. Zone D is the coldest, covering the country’s North; zone C runs across the middle of the country; Zone B includes southern B.C., Ontario and much of the Maritimes; while Zone A covers only the southern coastal region of B.C.
Windows can be rated with more than one of those zones. The more zones it’s qualified for, the greater the energy efficiency, so consider getting a window graded for a zone cooler than the one you live in.