Awnings are popular in hot sunny climates because awnings do such a good job of blocking solar heat before it gets to your windows. Though awnings can significantly improve the comfort of homes in the hottest regions, awnings are more expensive than other shading schemes such as trees, sun screens, and window films.
Awnings can cover a single window, a door, or an entire patio. Retractable awnings—although expensive—give maximum shade during heat waves while allowing sunshine to enter and maintaining a view during cooler weather.
Custom-made awnings usually have side panels that make them more effective at blocking a variety of the sun’s angles throughout the day. Do-it-yourself awnings, which often lack sides, are more effective if they are wider than the windows they shade.
Awnings should be large and low enough to keep direct sun from entering your windows. On your home’s south side, they should drop 45% to 60% of the distance from the top of the window to block sunlight from high in the sky. Awnings on the east and west need to drop 60% to 75% in order to block morning and afternoon sunlight that comes from lower in the sky. Depending on their drop, awnings can cut off a significant portion of a window’s view.
The cost of awnings varies widely. Custom-made aluminum or canvas awnings are more expensive than do-it-yourself awning kits or mass-produced awnings.
A radiant barrier blocks radiant heat transfer between the roof and the ceiling of a home. The radiant barrier is a sheet of aluminum foil with air spaces on one or both sides. ?A radiant barrier cuts air conditioning costs by blocking most of the heat flow that radiates from the roof downward into the attic insulation. In the spring and fall, radiant barriers may allow you to cool with ventilation and air circulation instead of with air conditioning. Radiant barriers can make porches and garages more comfortable, too. ?An aluminum foil radiant barrier can block up to 95 percent of the heat radiated down from the roof, and save 2 to 10 percent of total cooling costs. Insulation is a better investment than radiant barriers wherever the climate demands both heating and cooling. Homes with dark?colored roofs will benefit most from radiant barriers. ?Radiant barriers should be installed on the bottom of the rafters or the top cord of the roof truss as shown in figure 2?6. Don’t install the radiant barrier horizontally directly over the ceiling insulation because the shiny surface facing the roof will collect dust, reducing its effectiveness. If the radiant barrier is installed horizontally, it could also cause moisture problems.