Savings By Design
Competition Awards
Presentation June 15
Winners of the 2000 Savings By
Design Energy Efficiency Integration
Awards will be honored at the Annual
AIACC Awards on the Queen Mary,
Long Beach. For more information,
What You Plant on the Outside
Affects Energy Efficiency Inside
Amid all the discussion about advanced energy-efficient
technologies, one low-tech building component continues to
provide visual relief and beauty, and can contribute significantly
to a building’s energy efficiency. Skillfully designed landscaping
can play a major role in energy conservation by providing shade,
reducing heat and glare, and directing breezes. In other words,
what you plant outside the building can directly affect the energy
consumption inside.
visit the Savings By Design Web site at
www.savingsbydesign.com.
New Design Briefs Available
on the EDR Web Site
Explore more practical options you can
use for energy-efficient building
design:
• Building Simulation
• Daylighting
• Glazing
• Lighting Controls
Just visit the Publications page at
www.energydesignresources.com.
In the Next EDR E-News:
Energy Efficiency in
Sustainable Communities
Visit the EDR website at:
www.energydesignresources.com
Landscaping Factors that Deliver Energy Efficiency
In their "Strategies for Energy-Efficient Architecture" paper
prepared for the U.S. Department of Energy, University of
Hawaii (UH) researchers report that the key landscaping factors
that influence building energy efficiency are orientation, shading,
and wind intensity and direction.
Orientation and building shading: The researchers state that
the shape and orientation of a building will usually determine
how to locate plants and trees to provide shade at the right times
of the day. Medium-height trees a short distance from the east
side will provide shade through the late morning. From 10 a.m.
to 2 p.m., tall trees can shade the roof from high sun. Afternoon
sun from the west and northwest requires additional lower plants
and shrubs than does the morning sun, since it is hotter and more
intense. Trellises and hedges are particularly well-suited to
shading windows—the most critical areas to shade—since they
can easily admit glare and solar heat into the building.
Shading the surrounding grounds: Simply shading the
building will not do the whole job. Designers should also focus
on shading the ground and particularly the pavement around a
building. This can be especially important if a parking lot is
located on the windward side of the building, since the air
temperature immediately above an asphalt surface can reach
upwards of 120 to 150 degrees Fahrenheit. Even downwind, a
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Heliodon Now Available
at Edison CTAC
A new daylight modeling tool is now
available to the building design
hot paved surface will radiate heat into the building, increasing
the air conditioning load. The UH researchers report that
temperatures over grassy surfaces on a sunny day are 10 to 14
degrees cooler than those over exposed soils, and that ground
cover can also reduce glare around the building.
Directing air flow and ventilation: Rows of trees and hedges
can form wingwalls that direct air toward or away from
buildings. For ventilation, the researchers recommend orienting
tall plants perpendicularly to the window wall to channel air
flow toward the opening, as long as the design maintains solar
control. Vegetation can create areas of higher wind velocities by
funneling air through a narrow opening. Sometimes skillful
plantings can increase air flow 25 percent above that of the
upwind velocity. Because sunlit open areas with man-made
surfaces may heat the air above them, designers should minimize
them on the windward side of naturally ventilated buildings.
Ground cover planted upwind from a naturally ventilated
building can reduce the temperature and dust content of air
circulating into that building.
community at Southern California
Edison’s CTAC center in Irwindale.
Using Trees to Combat Urban "Heat Island" Effect
The heliodon includes an adjustable
table and solar light source that work
together, allowing designers to produce
a videotape that documents sun and
shadow patterns on a building over an
entire year in just a few minutes. This
record is useful in evaluating design
alternatives in buildings or retrofit
projects. For more information or to
reserve time using this new tool at no
charge, California-based practitioners
may contact Greg Sharp at
(626) 812-7368.
PG&E’s Pacific Energy Center in San
More and more American cities are becoming "heat islands"
whose downtown summer temperatures have been steadily
warming due to urbanization and deforestation, rising 0.5 to 1.0
degree per decade. In their paper entitled "Energy Wise Options
for State and Local Governments," Michael Totten and Nita
Settina report that an estimated five to 10 percent of urban peak
electric demand today is for additional air conditioning to
compensate for heat islands, with a corresponding cost to
ratepayers exceeding $1 billion per year.
According to scientists at Lawrence Berkeley National
Laboratory, trees are an extremely cost-effective strategy for
reducing summer cooling energy use in buildings compared to
the capital cost of the avoided air conditioning equipment. In
addition, the potential benefits from nationwide community
reforestation and a switch to lighter building and paving surfaces
could amount to savings of several billion dollars per year.
Francisco also has a heliodon available
for design practitioners’ use. For more
information, call (415) 973-7268.
To accomplish this nationwide reforestation, the American
Forestry Association (AFA) is encouraging communities to plant
100 million trees over the next five years through its Global
Releaf Project. According to the AFA, the average U.S. city
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currently has a 30-percent tree coverage that saves consumers nationwide close to $2 billion per year in
heating and cooling bills. However, the AFA estimates that our urban areas still have space available for more
than 300 million additional trees in urban areas (150 million in parks, 75 million around buildings, and the
rest along street corridors).
For more information on the energy efficiency benefits of careful landscape design, you can consult the
following Web sites.
Strategies for Energy-Efficient Architecture, University of Hawaii School of Architecture
Produced by the Honolulu Chapter of the AIA and funded by the U.S. Department of Energy
http://sundial.arch.hawaii.edu/HTMLpages/HaDesign/html/dstrat/4e/landscape.html
Energy Wise Options for State and Local Governments
By Michael Totten and Nita Settina
Center for Policy Alternatives
http://solstice.crest.org/efficiency/energywise_options/index.html
Global Releaf Project
American Forestry Association
http://www.amfor.org/garden/global_releaf/gr_subhome.html