Anyone sitting under a canopy on a hot Florida afternoon can appreciate the
cooling benefits of shade, but you may not be aware of just how effective
awnings are as a low-tech, low-cost way to cut summer cooling bills. According
to the California Energy Commission shading your home with exterior awnings can
reduce the temperature indoors by as much as 20o Fahrenheit on a hot day!
About 40 percent of the unwanted heat that builds up in your house comes in
through windows. Although both exterior and interior shades can control this heat
gain, exterior shades -- items such as awnings, bahama shutters, and solar
screens -- are far more effective, since they block sunlight before it enters
Awnings rate high because they block direct sunlight. Canvas or aluminum awnings
are attached above the window and extend outward and down. Properly installed awnings
can reduce heat gain in your home up to 65 percent on southern windows and as much as
77 percent on eastern and western windows.
A light-colored awning does double duty by also reflecting sunlight. Maintaining
a gap between the top of the awning and the side of your house helps to vent any
accumulated heat from under a solid surface awning. During cold winters retractable
awnings also allow homeowners to take advantage of the desirable winter heat gain.
Aesthetically, an awning mounted at an angle of 45 degrees is pleasing to the
eye. Make sure the awning does not project into the path of foot traffic unless it
is at least six feet eight inches from the ground.
The amount of drop you need -- how far down the window an awning should come --
depends on where the window is located. On the east or west side of the house, the
awning optimally needs a drop that covers 65 percent to 75 percent of the window.
Because of the higher angle of the sun, an awning on the south side needs to cover
only 45 percent to 60 percent of the window to produce the same amount of shade.
Slatted awnings allow limited viewing to help overcome this disadvantage.