Vol. 9 No. 1
March 18, 2003
#EPA
United States
Environmental Protection
Agency
HIRI NEWS
Heat Island Reduction
A r I V E
Results from the Philadelphia ECA's Cool Homes
Program, Overview of the Pacific Southwest Urban
Research Center Projects, Chicago Energy Code
Amendments, and More!
Call participants
Drew Ballensky, Duro-Last
(drewballenskv@hotmail.com')
Bonnie Beimer, Louisville AQMD
(bbiemer@loukv.org')
Fred Bell, Pacific Island Forestry
(fbell@fs.fed.us~)
Ryan Bell, ICLEI
(rbell@iclei.org')
Dean Brennan, Phoenix Planning
(dean.brennan@phoenix.gov)
David Brosch, Baltimore
(David.Brosch@baltimorecitv.gov)
Pamela Berger, City of Houston
(Pamela.Berger@citvofhouston.net)
Larry Budney, EPA R3
(budnev.larrv@epa.gov)
Janet Castellini,
Castle Education
(castle@eticomm.net')
Una Connolly, NAPA
(una@napa.hotmix.org')
Gerry Bakker, City of Chicago
(EN00237@citvofchicago.org')
Kathy Diehl, EPA R9
(diehl.kathv@epa.gov)
Ann Dougherty, ECCO
(ad o ug h e rtv@ce me nt. o rg)
Dana Easley, HARC
(deaslev@harc.edu)
Maury Estes, NASA
(Maurv.Estes@msfc.nasa.gov)
Rosalie Green, EPA
(green.rosalie@epa.gov)
Jim Grieger, USDA Forest
Service
(jgeiger@fs.fed.us)
Lucie Griggs, Atlanta Cool
Communities
(lwgriggs@hotmail.com)
John Haldaski, Philadelphia
(John.Hadalski@phila.gov)
Gordon Heisler, USDA Forest
Service
(gheisler@fs.fed.us)
Carey Hamilton, San Jose
(carev.hamilton@ci.si.ca.us)
David Hitchcock, HARC
(dhitchcock@harc.edu)
Brenda Johnson, EPA R4
(iohnson.brenda@epa.gov)
Gordon Kenna, Atlanta
(gkenna@mindspring.com)
Michelle Knapik, Philadelphia
(Michelle.Knapik@phila.gov)
Cheryl Kortemeier, Trees
Atlanta
(chervl@treesatlanta.org)
Caryn Lampier, Georgia DNR
(Carvn Lamphier@mail.dnr.state
.ga.us)
Ronald Landy, EPA R3
(landv.ronald@epa.gov)
Ed Linky, EPA R2
(linkv.ed@epa.gov)
Ronnen Levinson, LBNL
(RML27@cornell.edu)
Kathy Lord, Trees for Houston
(kathv@treesforhouston.org)
(linkv.ed@epa.gov)
Makela Mangrich, Austin
(Makela.Mangrich@ci.austin.tx.us)
Greg McPherson, USDA Forest
Service
(egmcpherson@ucdavis.edu)
Dennis Minks, City of Louisville
(dminks@loukv.org)
Susan Munves, Santa Monica
(susan-munves@santa-
monica.org)
Noa Oren, EPA
(oren.noa@epa.gov)
Karl Pepple, Houston COG
(kpepple@hgac.cog.tx.us)
Mel Pomerantz, LBNL
(M Pomerantz@lbl.gov)
Joyce Rosenthal, Columbia
University
(ir438@columbia.edu)
Jim Simpson, USDA Forest
Service
(irsimpson@ucdavis.edu)
Bruce Smith, EPA R3
(smith.bruce@epa.gov)
Larry Smith
(larrves@pacbell.net)
Elizabeth Stasiak, ICMA
(ESTASIAK@ICMA.org)
Linda Stone, City of San Antonio
(mpe@stic.net)
Harold Taft, AL Forestry
s(TaftH@forestrv.state.al.us)

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Diane Tentschert, Tucson
(DTentscI @ci.tucson.az.us')
Audrie Washington, EPA R5
(washinqton.audrie@epa.gov)
Eva Wong, EPA
(wonq.eva@epa.gov)
Barry Zalph, Louisville AQMD
(Bzalph@co.iefferson.kv.us')
Philly Cool Homes
Update
Liz Robinson, Executive Director of
the Philadelphia Energy
Coordinating Agency (ECA), spoke
to call participants about the city's
Cool Homes program and discussed
results to date. Liz said the program
was initiated to deliver energy
conservation services - including
cool roofs - to low income and
elderly residents. With 165,000
people in these categories, and with
several major heat waves over the
last several years, ECA's cool
homes program represents an
important mitigation strategy. To
date, the Cool Homes program has
installed over 450 cool roofs along
with other weatherization and
conservation treatments.
Liz discussed results from a
program analysis conducted by M.
Blasnik & Associates. Their work is
based on temperature and humidity
observations collected with data
logger at 35 houses. Six of the
houses were logged in the summer
2001 and treated before the summer
of 2002. Six other homes were
designated for the comparison group
and did not receive treatment during
the summer. This left 23 houses
with potential for short-term pre/post
analysis.
According to the report, "the
temperature data is showing clear
patterns of program impacts
consistent with expectations." In-
field observations show that white
roof coatings and R-38 insulation
nearly eliminate the impact of solar
heat gain through the roofs in the
target houses. Liz noted that indoor
ceiling-height temperatures were
reduced by about 5° F on hot
days and chest-height bedroom
air temperatures declined by
about half that amount.
The heat gain from the ceiling
was reduced by approximately
80% as ceiling temperatures
dropped to within half a degree of
2nd floor indoor air temperatures.
This means that the largest
single source of heat gain to
most flat roof row houses - the
roof system - is largely
neutralized. Interestingly, the
analysis determined that the
impacts on ceiling temperatures
were almost as large in houses
with air conditioning as those
without. The impacts on air
temperatures in homes with A/C
were also substantial despite the
use of air conditioners before and
after treatment.
The report concludes that all
analyses performed supports the
conclusion that the roof coating
has worked as expected.
However, the impacts of the
program-measures on occupant
health, comfort, and energy
usage is still being analyzed.
During the call, Liz addressed a
question about whether the
observed results were primarily
the result of cool roofs or the
insulation treatment that
accompanies roof installation.
She said preliminary results
suggest the coatings provide
most of the interior cooling
benefit, but that both treatments
are important. Liz said more
research still needs to be done in
this area.
Another topic on the call was
preliminary results from the
exterior data loggers. They
suggest that city blocks with
reflective rooftops can be slightly
cooler in summertime than
surrounding areas.
Because the Philadelphia Cool
Homes program provides an
important model for other cities,
it's goals are worth reiterating.
They are to reduce indoor
temperatures to a comfortable
level, minimize health risks,
stabilize energy consumption, and
provide social interaction and
outreach to seniors.
For more information, see:
http://www.ecasavesenergy.org/
Center for Urban Forest
Research UHI Work
Dr. Greg McPherson, Director of
the Center for Urban Forest
Research, joined the call to talk
about his work and how tree
planting can be an effective heat
island mitigation strategy. Greg
said that the purpose of the Center
is to find new ways for urban
forests to add value to
communities. This is typically
accomplished by stating research
results in financial terms.
The presentation started with an
explanation of how trees influence
energy use. This occurs as
follows: trees influence
intermediate climate effects,
including the amount of solar
radiation that hits the ground, air
temperatures, and wind speed.
These climate impacts, in turn,
affect the energy demanded for
cooling electricity and heating,
thereby impacting air quality and
carbon dioxide emissions. Greg
pointed out that direct energy
savings from trees depends on
their location from the building,
size, crown density, shape, and
leaf patterns. The Center provides
shade tree planting guidelines that
address these factors.
Slide 9 in Greg's presentation
illustrates another major factor in
determining potential energy
savings from trees: location within
the US. Residents and building
owners in Southwest cities, in
particular, stand to gain from
strategic planting. A study at the
Center is currently looking at the

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effects of "California's Urban Forests
on Energy Use." Even within the
state, results suggest a wide range
of potential energy savings based on
location. The study predicts
increasing savings in annual
electricity consumption overtime as
more trees are planted and existing
trees mature. It suggests that,
within California, the south- and mid-
central valley areas, and the high
dessert, have the greatest potential
for kWh saved per residential tree
planted after 15 years. These areas
are also where shade tree programs
can be most cost-effective.
In addition to energy savings, Greg
touched on the air quality and
carbon benefits of trees. These
occur via direct pollutant uptake,
avoided emissions from power
plants, and carbon sequestration. In
addition to the pollutant removal
mechanism, Greg noted that trees
are also a source of biogenic VOCs.
The Center's guidelines on tree
location and selection can be used
to calculate savings from tree
planting programs and to maximize
related benefits.
Slide 20 discusses EnergyWise, a
new software tool for strategic shade
tree planting. EnergyWise optimizes
energy savings via tree location and
selection, and provides information
on heating and cooling loads and
costs. The software also helps
evaluate the benefits of parking lot
vegetation. Preliminary results
suggest that there are substantial
cooling benefits - trees can make
lots up to 3 degrees cooler, cabin
space 20-25 degrees cooler and gas
tanks 2-4 degrees cooler. Five
percent shading can result in a one
ton/day VOC reduction.
The Center has also been doing
research in Sacramento to evaluate
the effectiveness of the city's shade
tree planting ordinance for parking
lots. Greg said that while the
specification requires 50% shade,
only 22% has been realized 15
years after the ordinance was first
passed. He estimates that it would
cost an additional $20 M to reach
the 50% target. The Center's
recommendations for cities
interested in pursuing a strategy
similar to Sacramento's is to use
ordinances, education (and
enforcement), and demonstration
projects.
For more information, see:
http://wcufre.ucdavis.edu/index.ht
ml
Two related papers from the
Center on parking lot shade can
be downloaded here:
http://wcufre.ucdavis.edu/product
s/11/cufr 69.pdf.
http://wcufre.ucdavis.edu/product
s/11/cufr 68.pdf
Cool Roof Amendment
to Chicago's Energy
Conservation Code
Gerry Bakker, of the City of
Chicago Department of
Environment, joined the call to
discuss revisions to the city's
Energy Conservation Code
relevant to heat island mitigation.
The amendments address the
city's explicit goal of reducing the
urban heat island effect through
the mandatory use of cool roofs
on all new and renovated low-
slope roofs. Gerry said they are
also consistent with Chicago's
goal of becoming one of the
greenest cities in the country.
Gerry noted that throughout the
standard-setting process, his
office worked with the local
roofing industry to assure their
necessary cooperation with the
amendment. In addition to health
benefits, the City believes the
provisions on roof reflectance will
be cost-effective for building
owners, especially when viewed
from a long-term perspective.
The code states that for low-
slope roofs, "Roofs installed prior
to and including 12/31/08 shall
have a minimum solar
reflectance, both initial and
weathered, of 0.25," and that,
"Roofs installed after 12/31/08
shall utilize roofing products that
meet or exceed the minimum
criteria to qualify for an Energy
Star label as designated by the
USEPA Energy Star program."
The methods used to evaluate
code compliance, according to the
amendment, are American Society
of Testing and Materials (ASTM)
E903, ASTM E 1918 (or,
alternatively, testing with a
portable reflectometer at near
ambient conditions).
The interim reflectance standard
of 0.25 that is now in place
through 12/31/08 replaces a
stepladder approach to reaching
the 0.65 Energy Star standard by
2009, and was agreed upon in
consultation with the local roofing
industry. A related proposal to
pass a reflectance standard of
0.15 for steep sloped roofs (typical
of the residential sector) faced
opposition from industry. Chicago
is working with the roofers to see if
a compromise can be reached.
It is also worth noting that the
standard offers exemptions to the
low-slope standard to
accommodate green roofs and
solar panels. It says, "The portion
of the roof that is covered by a...
rooftop garden, or a green roof, is
exempted from the requirements
of this section," and that, "An area
including and adjacent to rooftop
photovoltaic and solar thermal
equipment, totaling not more than
three times the area that is
covered with such equipment, may
be exempted from the
requirements of this section."
For more information, see:
http://www.citvofchicaqo.org/Buildi
nqs/BuildinqCode/AmendDiqest.p
df

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The next conference call
is TBD. Stay tuned for
the date, call-in number,
and access code.

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