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
.