Did you know that trees can help you to conserve energy? Vegetation cools the air, and different uses of trees and landscaping help reduce energy consumption throughout the year.

Heating / Cooling Effects of Vegetation

Surfaces Covered with Vegetation

• Since a tree is actively cooling the air surrounding it and intercepting radiant heat from the sun, anything found within its shade will be cooler than everything in direct sunlight.
• Tree branches and foliage, particularly evergreen trees with branches all the way to the ground block and redirect cold, winter winds away from nearby buildings.
• Trees are the air-cooling machines of the plant world, due to the large areas shaded by them and large amount of foliage releasing water vapor, which cools the air. Grass, shrubs, and other types of vegetation cool the air by releasing water vapor too.

Surfaces with no Vegetation

• Buildings can block cold, winter winds from other buildings, but homes with no landscaping are exposed to cold winds,resulting in greater heating costs.
• Surfaces such as pavement and shingles have no way to achieve a self-cooling effect like plants do. This leads to the “Urban Heat Island Effect," the phenomenon of elevated temperatures where paved, impervious surfaces are prominent, and cooler temperatures outside of cities where there are more natural areas.

Energy Conservation Through Shade

A high electric bill in summer months often results from an air conditioner working on overload to keep the house or building cool. With a little planning, a person can place trees in strategic locations where they will reduce the amount of money spent on energy over time.

To maximize the shade benefit of trees, try the following tree planting strategies:

• Plant deciduous shade trees on the east, south, and west sides of the structure. Shade from these trees will block the sun’s rays during summer months, but they will allow the sun to shine through in winter months when radiant heat could be beneficial. Plant at least 20 feet away from the structure to allow for enough growing space.
• Next to an air conditioner, plant a tree or large shrub on the south or west side at least 10 feet away. Shading the unit from direct sunlight will reduce the amount of energy used to cool the building.
• Plant trees alongside driveways where cars are parked to reduce interior temperatures, cutting back on the amount of fuel necessary to cool the vehicle.

Energy Conservation Through Windbreak

Winter winds tend to pierce through door and window frames and increase the demand on a heater for maintaining a comfortable indoor temperature. Evergreen trees (trees that hold their leaves or needles through the winter) are the best candidates for a living screen outside the home. By planting a wall of evergreens of varying mature heights on the north side of a structure, some of the winter winds can be redirected, resulting in a lower utility bill due to reduced heating costs.