Trees and Energy Conservation

Using Trees for Energy Conservation

Did you know that trees can help you to conserve energy? Vegetation cools the air surrounding it, and different uses of trees and landscaping help reduce energy consumption in hot and cold seasons. You can utilize landscaping to prevent your heating and cooling appliances from having to work too hard in temperature extremes.

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 and prevent them from blowing at and reducing the temperature of nearby buildings.
  • Trees are the air-cooling machines of the plant world, not only because they are larger than other plants in general, but also because they grow much taller than other types of plant life and cast a large amount of shade.
  • When the sun beats down on plants such as grass, shrubs, and trees, those plants lose water into the air in the form of vapor, which cools the surrounding air.

Surfaces with no Vegetation

  • Buildings can block cold, winter winds from other buildings, but homes that stand alone 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 is why we hear about the “Urban Heat Island Effect," which describes the phenomenon of elevated temperatures where paved, impervious surfaces are prominent and cooler temperatures outside cities / in the rural areas that have more pastures and forested land.

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.

Tree-Planting Strategies

To maximize the shade benefit of trees, try the following tree planting strategies:
  • Plant deciduous shade trees that will grow to a large height on the southeast, south, and southwest sides of the structure. Shade from these trees will block the sun’s rays during summer months when the rays are the strongest, but they will allow the sun to shine through in winter months when a little extra heat is needed. 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. This will shade it from direct sunlight. An air conditioner that is in full sunlight has to work much harder to cool a structure than a unit in the shade.
  • Plant trees alongside driveways where cars are parked to reduce inside temperatures, which will cut 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 extent to which a heater must run to keep a comfortable indoor temperature. Thankfully, a well insulated home keeps out a draft, but think about how much an outdoor insulation layer could add to that protection.

Tree-Planting Strategies

Evergreen trees or trees that hold their leaves or needles through the winter are the best candidates for a living screen. 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 electric bill due to reduced heating costs.