Over the next few weeks, Regreen Springfield will be announcing an effort to plant trees in your yard that can help to reduce energy consumption in your own home. The correct placement of a tree near your residence can help to reduce the amount of energy needed to cool, and in many cases, heat your home. Simple benefits, such as providing shade over your air conditioner can provide up to a 10% efficiency improvement. Other direct benefits can be obtained by planting trees, and Regreen Springfield hopes to help plant over 500 trees on private property this summer.
Stay tuned for the details of this ambitious initiative in Springfield. In the meantime, take a look at some of the background information presented below. It should get you excited about adding a tree or two in your own yard —-
A study of Chicago’s urban forest found that increasing tree cover by 10 per cent (an additional three trees per building) would reduce total heating and cooling energy use by 5 to 10 per cent . At a national level, researchers estimate that planting three additional trees for each building in the United States could save more than US$2 billion in energy costs annually (McPherson, 1994; Akbari et al., 1988). Tree windbreaks have been found to reduce residential heating costs by 10-15 percent, while shade and evapotranspirational cooling from trees have been found to reduce cooling costs by 20-50 percent (Dwyer, 1993; Laverne and Lewis, 1995). A study of benefits and costs of tree planting in Chicago found that the projected value of trees (e.g., pollution reduction, energy saving, property value) is nearly three times greater than the projected costs (McPherson, et. al., 1995).
On hot summer days, a tree can act as a natural “evaporative cooler” using up to 100 gallons of water a day and thus lowering the ambient temperature (Kramer and Kozlowski, 1960). Several investigators have documented dramatic (30 – 50%) differences in cooling-energy use between houses on landscaped and un-landscaped sites (Akbari, 2002). Computer simulations using standard building and tree configurations for cities across the U.S. indicate that shade from a single well-placed, mature tree (about 25-ft crown diameter) reduces annual air conditioning use 2 to 8 percent and peak cooling demand 2 to 10 percent (Simpson and McPherson, 1996).
The ambient air temperature difference between an urban heat island and a vegetated area can be as much as 2-10 degrees F. The temperature measured directly above man-made surfaces can be as much as 25 degrees F hotter than the air temperature beneath a forested area (Akbari et. al., 1992; Simpson and McPherson, 1996).