Energy Efficient Landscaping

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Energy Efficient andEnergy Efficient and

Environmentally ResponsibleEnvironmentally Responsible

LandscapingLandscaping An IntroductionAn Introduction

Prepared byPrepared by

Debra Rowe, Ph.D.Debra Rowe, Ph.D.

[email protected]@oaklandcc.eduPrepared for CERET under a grant from thePrepared for CERET under a grant from theNational Science FoundationNational Science Foundation


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Why should we care about energy supplies?

It is a national security issue causing

the following threats to our

well being:

Political Instability

Economic Instability

Environmental Instability


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Political Instability = Dependency

on foreign oil

The U.S. imports 54%of its oil consumption.

U.S. oil production hasdeclined continuouslysince 1974.

Thanks to John Richter for this slideSource: University of Minnesota


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Political Instability =

Dependency on foreign oilMuch of our oil comes from

Middle Eastern countries whosepolicies we dont like


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Economic Impacts"Paid predominantly by

the US, the costs of

protecting our MiddleEast oil supplies areas high as $15-25 abarrel - that is abouta dollar a gallon.

Peter Hain, UK Europe

MinisterUSS Stark, 1987


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Environmental Impacts - Disease power plant particle

pollution causes more

than 603,000 asthmaattacks per year..

Source: Abt Associates:

Death, Disease, andDirty Power Plants

Thanks to John Richter for

some of these slides.


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Environmental Impacts - DeathAbt Associates finds

over 30,000 deaths

each year areattributable to fine

particle pollution from

U.S. power plants.

Source: The Clean the Air Task Force


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4

Burning Fossil Fuels Produces

the Greenhouse Effect and Climate Change


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Environmental Effects -Climate Change1. Disruptions of food production

2. More extreme weather events

3. Unknown disruptive effects on cosystems4. Spread of disease to temperate climates

5. Submersion of land masses

up to 45 feet of sea level rise6. 140,000 deaths per year attributed to

climate changeSources: Intergovernmental Panel on Climate Change (2000

scientists from around the world; EPA of the U.S. )


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Terrorist threats

Centralized power plants are

much more vulnerable to terroristattacks than distributed

generation via wind, solar and

other renewable energies


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Why should we care about energy supplies?

It is a national security issuecausing the following threats toour well being:

Political Instability

Economic Instability Environmental Instability


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What can we do about it?1. Learn energy/environmental literacy as it relates

to landscaping

2. Become environmentally responsible landscapedesigners, technicians, marketers, etc.

3. Provide upgrade training to existing professionals

in architecture, construction, landscaping, HVAC,

building inspectors, community planners and more

4. Make better choices as consumers/investors


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Energy Efficient Landscaping

Landscaping is a natural and beautiful way tokeep your home cool in summer and reduce

your energy bills. In addition to addingaesthetic value and environmental quality toyour home, a well-placed tree, shrub, or vinecan deliver effective shade, act as a

windbreak, and reduce overall energy bills.


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Energy Efficient Landscaping ReducesOur Dependence on Fossil Fuels and

Saves Energy And Money!

Carefully positioned trees can save up to25% of a typical household's energy

used for heating and cooling. Computermodels from the U.S. Department ofEnergypredict that just three trees, properly placedaround the house, can save an average

household between $100 and $250 in heatingand cooling energy costs annually.


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Energy Efficient LandscapingReduces Pollution Too!

Studies conducted by Lawrence BerkeleyNational Laboratory found summer daytime

air temperatures to be 3 to 6F cooler intree-shaded neighborhoods than in treelessareas. That could be a 9 to 20 % savings incooling costs. The energy-conserving

landscape strategies you should use for yourhome depend on the type of climate in whichyou live.


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Landscaping and Your

Regional Climate

The energy-conserving landscape

strategies you use should depend on whichregion you live in.The United States can be divided into fourapproximate climatic regions: temperate,

hot-arid, hot-humid, and cool. See the map

to find your climatic region.


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1.Maximize warming effects of the sun

in the winter.

2.Maximize shade during the summer.3.Deflect winter winds away from

buildings.

4.Funnel summer breezes toward the

home.

Temperate Region This

includes Michigan


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Hot-Arid Region

1. Provide shade to cool roofs, walls, andwindows.

2. Allow summer winds to accessnaturally cooled homes.

3. Block or deflect winds away from air-

conditioned homes.


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Hot-Humid Region

1. Channel summer breezes toward thehome.

2. Maximize summer shade with treesthat still allow penetration of low-angle winter sun.

3. Avoid locating planting beds close tothe home if they require frequentwatering.


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Cool Region

1. Use dense windbreaks to protect thehome from cold winter winds.

2. Allow the winter sun to reach south-facing windows.

3. Shade south and west windows and

walls from the direct summer sun, ifsummer overheating is a problem.


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It's also important to consider your

home's microclimate in your

landscaping strategy.

Your home's microclimate may

receive more sun, shade, wind, rain,

snow, moisture, and/or dryness thanaverage local conditions.


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Microclimate (continued)

If on a sunny southern slope, you may

have a warm microclimate, even if you live

in a cool region.

Even though you live in a hot-humid

region, your home may be situated in a

comfortable microclimate because ofabundant shade and dry breezes.


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Microclimate (continued)

Nearby bodies of water may increase

your site's humidity or decrease its air

temperature.

Microclimatic factors also helpdetermine what plants may or may

not grow in your landscape.


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Shading1. Deciduous trees with high, spreading crowns (i.e.,leaves and branches) can be planted to the south ofyour home to provide maximum summertime roofshading. Trees with crowns lower to the ground aremore appropriate to the west, where shade is needed

from lower afternoon sun angles. Trees should not beplanted on the southern sides of solar-heatedhomes in cold climates because the branches ofthese deciduous trees will block some winter sun.

2. Although a slow-growing tree may require many years

of growth before it shades your roof, it will generally livelonger than a fast-growing tree. Also, because slow-growing trees often have deeper roots and strongerbranches, they are less prone to breakage bywindstorms or heavy snow loads. Slow-growing treescan also be more drought resistant than fast-growing

trees.


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Shading (continued)3. A 6-foot to 8-foot (1.8-meter to 2.4-meter) deciduous tree

planted near your home will begin shading windows thefirst year. Depending on the species and the home, the

tree will shade the roof in 510

years.If you have an airconditioner, shading the unit can increase its efficiency

by as much as 10%.

4. Trees, shrubs, and groundcover plants can also shadethe ground and pavement around the home. Thisreduces heat radiation and cools the air before it

reaches your home's walls and windows. Use a largebush or row of shrubs to shade a patio or driveway.Plant a hedge to shade a sidewalk. Build a trellis forclimbing vines to shade a patio area.


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Shading (continued)5. Vines can also shade walls during their first growing

season. A lattice or trellis with climbing vines, or aplanter box with trailing vines, shades the home's

perimeter while admitting cooling breezes to the shadedarea.

6. Shrubs planted close to the house will fill in rapidly andbegin shading walls and windows within a few years.However, avoid allowing dense foliage to grow

immediately next to a home where wetness or continualhumidity are problems. Well-landscaped homes in wetareas allow winds to flow around the home, keeping thehome and its surrounding soil reasonably dry.


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L

andscape windbreaks1. Basically, a windbreak can lower the wind chill near your home. Wind chill

occurs when wind speed lowers the outside temperature. For example, ifthe outside temperature is 10F (-12C) and the wind speed is 20 miles perhour (32 kilometers per hour), the wind chill is -24F (-31C). A windbreakwill reduce wind speed for a distance of as much as 30 times thewindbreak's height. But for maximum protection, plant your windbreakat a distance from your home of two to five times the mature height ofthe trees.

2. The best windbreaks block wind close to the ground by using trees andshrubs that have low crowns. Dense evergreen trees and shrubs planted tothe north and northwest of the home are the most common type ofwindbreak. Trees, bushes, and shrubs are often planted together to block or

impede wind from ground level to the treetops. Evergreen trees combinedwith a wall, fence, or earth berm (natural or man-made walls or raised areasof soil) can deflect or lift the wind over the home. Be careful not to plantevergreens too close to your home's south side if you are counting onwarmth from the winter sun.


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Landscape windbreaks (cont.)

3. If snow tends to drift in your area, plant low shrubson the windward side of your windbreak. Theshrubs will trap snow before it blows next to your

home.4. In addition to more distant windbreaks, planting

shrubs, bushes, and vines next to your house createsdead air spaces that insulate your home in both winterand summer. Plant so there will be at least 1 foot(30 centimeters) of space between full-grown

plants and your home's wall.5. Summer winds, especially at night, can have a

cooling effect if used for home ventilation. However, ifwinds are hot and your home is air conditioned allsummer, you may want to keep summer winds from

circulating near your home.


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Landscaping Water ConservationYou can design a landscape that not only

conserves energy but also water. Here is a brief

overview of some water-conserving landscaping

strategies.

Xeriscaping

Xeriscaping is a systematic method of promoting

water conservation in landscaped areas. It's basedon seven principles:


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1. Planning and design

Provides direction and guidance, mapping your water and energyconservation strategies, both of which will be dependent upon your regionalclimate and microclimate.

2. Selecting and zoning plants appropriately

Bases your plant selections and locations on those that will flourish in yourregional climate and microclimate.

3. Limiting turf areas

Reduces the use of bluegrass turf, which usually requires a lot ofsupplemental watering.

4. Improving the soilEnables soil to better absorb water and to encourage deeper roots.

5. Irrigating efficiently

Encourages using the irrigation method that waters plants in each areamost efficiently.

6. Using mulches

Keeps plant roots cool, minimizes evaporation, prevents soil from crusting,and reduces weed growth.

7. Maintaining the landscape

Keeps plants healthy through weeding, pruning, fertilizing, and controllingpests.

Xeriscaping is mostly used in arid regions, but its principles can be used inany region to help conserve water.


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Watering

If you can determine how much water your plants actually

need, then you won't overwater them and waste water. It is

important to not only understand a plant's particular watering

requirements, but also evapotranspiration.Evapotranspiration

is the amount of water that is evaporated from the soil and

transpired through the plant's leaves. This amount of water

needs to be replaced through watering. If you know yourarea's Et rate, you can plan the amount of water to be

replaced through irrigation. Call your local water district or

cooperative extension service and ask about your Et rate.

However, your particular microclimate will also affect

evapotranspiration in different areas of your yard. Also, it'sbest to water or irrigate your plants in the early morning when

evaporation rates are low. This also provides plants with

water before mid-day when the evaporation rate is the

highest.


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Additional Resources on Water

ConservationEvaluation Tools

1. WaterAideDOE Building Energy Software Tools Directory

2. Xeriscaping: Creative Landscaping -http://www.ext.colostate.edu/pubs/garden/07228.htmlColorado State University Cooperative Extension

3. XeriscapingToolbase Services

4. LandscapingH2ouse.org - California Urban Water ConservationCouncil


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A note about solar energy. Ifdesigning a building to use solar:

Unobstructed access to the sun is necessary for the optimumperformance of active and passive solar energy systems. Thereis generally no guarantee a solar system will always haveunobstructed access to the sun. Every day, decisions about thebuilt environment and landscape effect the future shading ofexisting or potential sites.

Solar access protection is clearly advantageous for the followingsystems in the associated locations:

Rooftop- solar water heater and space heating collectors andphotovoltaic arraysSouth facing walls- passive solar systems such as Trombe walls,attached solar greenhouses, and direct gain systems such aswindows and glassLot (south-facing)- ground-mounted or detached active collectorsystems.


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Permaculture

Permaculture philosophy is landscapingand agriculture that works with, ratherthan against nature to create sustainable

human environments. It is sometimesdescribed as low maintenance, low energyand oftentimes edible landscaping.

For more information, go to

ATTRA - National SustainableAgriculture Information Service at

http://www.attra.org/attra-pub/perma.html


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In conclusion:

Landscape practices can help or hurtecosystem and human health

There are principles of environmentallyresponsible landscape design that shouldbe incorporated into all landscapingprojects

There are precedents and resources to

assist you What you do makes a difference

Documents

Energy Efficient Landscaping