Bayview Logo

Energy Efficiency

Keep energy costs down and comfort level up with window orientation optimization

Windows provide light, warmth and ventilation, but they also decrease home energy-efficiency and can affect the comfort in your home. Choosing the right glass option will allow you to find a balance between energy costs and the desired level of home comfort.

Blog entry > Keep energy costs down and comfort level up with window orientation optimization

No matter what the season, when it comes to energy-efficient windows there are several factors to think about:

  • 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.

Taming the power of the sun

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 a general rule windows that:

  • Face the direct south are exposed to the sun for almost the entire waking day
  • Face east get morning sun exposure
  • Face west get afternoon and early evening sun exposure

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 a desired comfort level on a room-by-room basis. Have a look at a few scenarios below.

Scenerio 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 emmisive 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

Scenerio 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 emmisive LoE 366 glass for all your windows and the sliding pation 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

Scenerio 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 tripple 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 scenerio?

Contact your professional window replacement specialist and tell them how you would like to improve the comfort and energy efficiency of your rooms.

Defininition of terms used in story:

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 refers to the glass framed within a window (IGU’s - insulated glass units). In Canada, double-gazed 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 save money on energy costs.

Need help finding a balance between home comfort and window efficiency, leave the guessing out of it, 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.