Blog > Category > Posted: 2023-Jul-20, Updated: 2023-Apr-05
Keeping your energy costs down and comfort level up
No matter what the season, when it comes to energy-efficient windows there are several factors to think about:
- The orientation of home with respect to the sun
- Seasonal shading elements such as trees or buildings
- Interior window treatments
- Permanent awnings or shutters
Where’s the sun?
We all know the sun rises from the east and sets in the west. However, that’s not entirely true. In Ottawa for example, the sun actually rises somewhat south-east in the summer and even more south-east in the winter and it sets somewhat south-west.
In Ottawa, the sun is never directly above us at any point during the day no matter what month of the year, or time of day.
In Ottawa, as general rule windows that:
- Face east get morning sun exposure
- Face south are exposed to the sun for almost the entire waking day
- Face west get afternoon and early evening sun exposure
- Face north don’t get much sun at all
Knowing where the sun is going to be, allows us to take advantage of glass options (coatings, glazing and tints) that can help us produce the desired comfort level on a room-by-room basis.
Have a look at a few scenarios below.
Scenario 1 - Warm your home
Situation:
Your living room with a large picture window faces south, large trees provide shade to the room in the summertime, but the room is fully exposed to the bright sun in the winter. You want to take advantage of the solar heat gain to help warm your home in the winter, but you don’t want it to be too bright and you are concerned UV light may damage your furniture.
Possible solution:
Select low emissive LoE 180 glass.
- Reduces energy costs in the winter
- Highest Energy Star energy rating
- U-factor of 0.31
- Maximized solar gain of SHGC 0.68
- Allows for 79% light transmittance
- Blocks 70% of damaging UV rays
Scenario 2 - Control the brightness
Situation:
You have a large family room facing south-west, it has several casement and picture windows along with a sliding patio door which leads to a deck. You like the light coming into the home and you would like not to have to close all the blinds in the afternoon because it is too bright and too hot in the summer. In the winter you find the room too bright and too cold. And you want to protect your leather furniture from damaging UV rays.
Possible solution:
Select low emissive LoE 366 glass for all your windows and the sliding patio door.
- Best insulation option - keeps heat and sun out of home and hot/cold inside the home
- U-factor of .29
- Maximized solar gain of SHGC 0.27
- Allows for 65% light transmittance
- Blocks 95% of damaging UV rays
Scenario 3 - Keep the cold out
Situation:
You have a large bedroom with a modular picture window with 2 casement side windows that faces north. The blinds are always open during the day to let light and the room is always cold at night. In the winter the room is always cold and the windows seem to have more condensation than other windows facing south, east and west.
Possible solution:
Replace existing windows with triple glazed (pane) argon filled windows
- Best insulation option - keeps the hot/cold out of the home
- Keeps inside heat and airconditioning inside the home.
- U-factor as low as .16
- No solar gain as the window is not exposed to direct sunlight
- No damaging UV rays as the window is not exposed to direct sunlight
- Allows for 98% light transmittance
Want to resolve your own scenario?
Contact your professional window replacement specialist and tell them how you would like to improve the energy efficiency and comfort and of your home.
Definition of terms used in the story:
Low Emissive Glass
Low emissive glass has a distinct microscopically thin layer of silver applied to the surface which acts to reduce the amount of heat that can flow through the glass. It reflects heat in both directions keeping heat out in the summer and in during the winter. Low E glass is available in several configurations to produce the desired balance between solar gain (heat), light transmittance and UV blocking.
Tinted glass
absorbs and re-radiates light and solar energy reducing heat, brightness, and glare in the summer, but tinted glass loses heat in the winter at the same rate as non-tinted windows.
Window glazing
Window glazing refers to the glass-framed within a window (IGU’s - insulated glass units). In Canada, double-glazed glass is pretty much the standard, but triple-glazed windows are also available. The more layers of glass, the higher the thermal insulation factor, (R-value) which can help you save money on energy costs.
Related topics
Need more information?
Need help finding a balance between home comfort and window efficiency, leave the guessing out of it, and talk to your local window specialist. They’ll help you find the perfect window, that will maximize your home comfort and minimize your energy costs.
If you would like to know more about our window and door products and their energy efficiency potential, we'd love to hear from you. Better still, why not schedule an appointment and come in and see our products for yourself?
