It also serves aesthetic purposes. A windbreak, for example, can define the space in a yard or patio and provide privacy while blocking blustery winds. Energy saving strategies for buildings are in large part determined by geographic location. The U. Department of Energy has divided up the United States into four climate regions — cool, temperate, hot and arid, and hot and humid — and has recommended these landscaping strategies for each zone:.
Image credit: Landscape For Life. Trees and shrubs provide shade around a Texas home. Image credit: Sally and Andy Wasowski. A variety of beautiful vines, shrubs and trees with appropriate sizes, densities and shapes are available for almost any shading application. To block solar heat in the summer but let much of it in during the winter, use deciduous trees. To provide year-round shade in hot climates, use evergreen trees, shrubs and vines. Trees often grow slowly, but homeowners can moderate hot sunshine quickly using vines that clamber up strategically placed trellises.
Permanent structures such as trellises are most appropriate in hot climates where blocking solar heat gain in winter is not counterproductive. Where wetness and humidity are a problem, keep the trellis at least a foot away from the house to allow for air circulation; in these areas air should be allowed to flow around the home, keeping the structure and surrounding soil dry to prevent mildew and rot. Arbors or pergolas can help shade windows, too, and are a better choice in temperate regions if the lower winter sun can still penetrate the windows to warm the house.
Annual vines grow quickly and can cover a large area by mid to late summer. Homeowners can make shading devices twice as functional by growing vines that not only provide shade but also fruits or vegetables. Edible vines such as scarlet runner beans, winter squashes and luffa squashes are both vigorous and fast growing. Ornamental vines are also good candidates, especially if they offer food and shelter for wildlife.
Cypress vine and scarlet creeper provide nectar for hummingbirds, for example, while moonflower attracts moths. Large trees and shrubs take longer to fill in but provide the best cooling shade.
The air temperature can be as much as 25 degrees Fahrenheit cooler under trees than around nearby asphalt lots. As is true for vines, in cool and temperate climates placing trees for summer shade and winter sunshine is more complicated than it would first appear. Large specimens that shade the roof and walls from the afternoon sun can reduce indoor temperatures by as much as 8 to 10 degrees Fahrenheit.
Trees should be located close enough to the house to cast shade but far enough away typically about 15 feet that their roots will not damage the foundation.
Homeowners should also consider how wide the trees will become when mature, and space them accordingly. Homeowners should work with neighbors to plan and plant an energy-conserving neighborhood landscape that improves conditions and lowers costs for everyone. Deciduous plants are the best shading devices. They can shed their leaves in response to the change in temperature. Deciduous plants may also cause more harm during winter than good in the summer if those plants are not carefully placed on the southern side of a building.
The Wind is an important climatic factor that has to be considered in a landscape design. These shelter belts, formed by rows of trees and shrubs can reduce the wind speed or redirect its movement. Plants that can withstand the winter climate conditions have to be selected for windbreak systems. It is an effective technique to use evergreen species as the major constituent of a windbreak composition. They occupy a significant portion of the system as these plant species retain wind-blocking mass in winter.
Distance between the tree and building depends upon the tree height. The Optimum distance is usually taken as 1 to 3 times the windbreak height. Distance up to which the wind can be reduced depends upon the height of the tallest row. It is considered to be 30 times the height. The effective distance of a windbreak system is generally indicated based on the windbreak multiplier, which is measured from the middle of the outermost layer of vegetation, downwind, along a line following wind direction.
Components of a windbreak system have to be closely spaced to act as a continuous barrier against the wind.
It is necessary to consider the final form that plant species will achieve once they get matured. Deciduous plants with narrow clowns can be used and these plant species have to be densely planted. A single species, a set of 2 species, or a mixture of species can be used to form this windbreak system. Each row of the windbreak has to be densely planted in the same way as in a one-row windbreak.
Three-row windbreaks are composed of 3 rows of trees or shrubs. It should include at least one row of dense evergreen trees. Other rows can be either deciduous or evergreen plantings. Shrubs can also be used as a front-row to catch the snow, if necessary.
The three-row system provides additional sheltered spaces and there is a possibility for greater diversity.
Thus, the three-row windbreak system has more wildlife value than a single or double-row system Figure 8. Wind-shadows created by landscaping. The mature size of plant species has to be considered in designing the landscape.
The growth rate is thus an important factor. Fast-growing plant species may not be a good choice as most of these species have poor strength even though some vines are effective fast-growing species that can be used in landscaping. Man-made structures such as a pergola, framework, wall, etc. Vines can also act as shading devices. Vegetation can guard buildings from the cold winds during winter. It also provides shade from the summer sun and controls the solar radiation during different periods of the year.
The climate of hot-humid zones is characterized by high rainfall and high humidity. Due to minimal temperature differences, winds are light or even non-existent for longer periods. However, heavy precipitation and storms occur frequently. Landscape design strategies can be used to maximize the shade throughout the year and improving the air movement, thus increasing thermal comfort. These can provide comfortable outdoor areas and solar protection.
Planting beds that require frequent watering have to be avoided in areas adjacent to the building. Plant species that allow penetration of low-angle winter sun have to be used for shading the buildings and outer spaces Figure 9.
Source: Created by Nivedhitha Ravichandran. These trees allow the movement of air underneath the canopies. Low vegetation has to be kept away from the building. This allows breezes to pass through and also prevents dampness. Channeling prevailing winds with appropriate landscaping.
Other strategies which shall be adopted to minimize the discomfort occurred due to hot and humid climatic conditions like buildings should be separated with large, free spaces between them.
This allows airflow which provides ventilation for cooling and a hygienic environment. Certain species of trees e. They should not be planted too far from each other, so that the crowns form a wide hall-like space, creating a comfortable microclimate. An un-shaded pavement should be avoided as far as possible and air should not be allowed to pass over such hot surfaces before reaching buildings. High bushes, however, should be avoided near buildings because the space between the ground vegetation and the high crowns of the trees should remain open, providing free access for the wind at the level of the living spaces.
The hot and dry climate, it is imperative to control solar radiation and movement of hot winds. The design criteria should therefore aim at resisting heat gain by providing shading, reducing exposed area, controlling and scheduling ventilation, and increasing thermal capacity. Hence, strategy should be such that it should prevent formation of dry dusty air due to overheating.
It should maximize filtered air movement in summer. Vegetation is desirable as a radiation absorbent surface and for it has evaporative and shade giving properties. This helps to improve shade. Solar heating of the southern walls can be regulated by using shade trees or trellis structures with vines.
Vines help to cool the air adjacent to it via transpiration. Energy Tech Tips Community. Here are our top 5 ways for saving energy through just by how you landscape: Plant Shrubs and Groundcover Plants Not only is this option aesthetically pleasing, but it also aids in cooling the air that reaches your home, reducing costs coming from your air conditioning. Plant Climbing Vines with a Trellis or a Lattice Climbing vines are a fun and original way to conserve energy.
Plant Deciduous Trees on South or West side of Your Home Deciduous trees trees that lose their leaves in the winter can save you hundreds of dollars a year on your home energy bills if planted on the south or west side of your home. Set Up Evergreen Trees and Shrubs to the North and Northwest of Your Home Evergreen plants work most effectively as windbreaks, making them a great, natural option for keeping your home warm during the winter.
Install Solar Lighting Outdoors Did you know that solar powered accent lighting exists for walkways, gardens, and driveways and are a reliable and affordable alternative to regular outdoor lighting?
Keep Reading. To plant for shade effectively, you need to know the size, shape and location of the shadow at different seasons and different times of the day. In most cases, if you plant a foot deciduous tree near your home, it will start shading your windows in the first year, and your roof in years. Keep in mind that vines, shrubs and bushes can effectively shade walls and windows and may be enough in certain regions. In more northern climates and cooler areas, the primary goal may be to allow sun to penetrate the southern portions of the home in the winter.
Radiant heat and natural daylight can help save in heating and lighting costs. If there is no concern over winter winds from the south, you may not need any trees or shrubs on the south sides of the home.
Like any type of landscaping, be sure to research your local region and seek help from your county extension, local nurseries, professional landscapers and other resources. Landscaping is an investment in your home and property as well as a potential investment in energy savings! Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Sign Up.
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