Saturday, August 9, 2008
Cut down on energy costs with proper tree placement
It's time for an inventory -- a summer shade inventory, that is.
A shade inventory can help you find ways to shade your home and cut down on energy costs.
You will see benefits of adding trees and other plants to a home landscape. For example, adding small shrubs to shade your air conditioner can increase its efficiency by as much as 10 percent, according to the U.S. Department of Energy.
To start a shade inventory, analyze your yard and how you use it, according to Edith Makra, Morton Arboretum arborist and Community Trees Advocate. Sketch a bird's eye view of your lot including all buildings and window placements, and indicate which direction they face. Note outdoor features like patios and swing sets, and when they are most used. Sketch in existing trees and shrubs. Then check your yard at different times of the day and note where shadows move.
Next, think about where you want more shade for energy efficiency and comfort.
West is best. Placing a deciduous tree (one that loses its leaves in the fall) on the west side blocks hot, afternoon sun in summer, and as this tree "exhales" moisture, this, too can cool your house. Then install smaller trees and shrubs on the east side.
"People tend to shade the south side of the house, but must do so carefully," said Makra. Plant a large, deciduous tree with large leaves and an oval or spreading shape near the southwest side of your home. "It's best if the canopy is high enough to shade the roof in summer, but in winter, the sun's warming rays can heat the house without the branches blocking any light. Allowing full southern sun exposure for warmth in the winter outweighs the benefits of summer shade on the south," Makra said.
To better pinpoint where to plant a new tree, Makra suggests holding up your patio umbrella at different times of the day. Note how the shape and size of the shade circle changes.