Canada Builds

Angle of Incidence

The angle of incidence is the angle at which a ray of light strikes a surface. In this case, the angle of incidence is examined with respect to a vertical piece of glass. In the drawing sketch shown above, when the angle of incidence is 90 degrees to the window is when the most solar radiation will come through to the inside of the building. As the angle of incidence increases (or moves up), most of the radiation is still transmitted to the interior up to an angle of around 50 degrees. At this point the light transmission tapers off quickly to zero.

When the sunlight gets into the building, there are different ways to capture the energy. Consider a passive solar system such as a thermal floor or a thermal wall to capture the radiant energy that comes through the wondows.

For more information on the energy of the suns rays that come through a window see the Window Performance Page