In a report, Guidelines for Selecting Cool Roofs, July 2010, the U.S. Department of Energy makes the following observations:
• Climate has the biggest impact on energy savings.
Cool roofs achieve the greatest cooling savings in
hot climates (Climate Zones 1-3) but can increase
energy costs in colder climates due to reduced
beneficial winter time heat gains.
• When cool roofs are optional yet encouraged, the
decision should be considered carefully as cool
roofs do not perform equally well everywhere.
• The energy cost savings you can realize from a
“cool”(white) depends on many factors, including
where you live.
• Although annual cleaning can restore up to 90% of
initial reflectance, the energy cost savings alone
does not warrant the cost.
• As a cool roof becomes dirty from pollution, foot
traffic, wind-deposited debris, ponded water, and
mold or algae growth, its reflectance will
decrease, leading to higher temperatures.
• There are some important questions about the
durability of cool roof systems in certain applications.
• In colder climates, like Chicago or Alaska (Climate
Zones 5-8), there is less heat available
to dry out the roof and more opportunities for
condensation to occur.
Longest Lasting Commercial Roofing Product In The Industry… Bar None
Sus-tain-a-ble [suh-stey-nuh-buhl] adj. Pertaining to a system that maintains its own viability.
Characteristics that contribute to EPDM’s overall system performance include:
• Long-lasting performance
• Outstanding weathering characteristics
• Unmatched resistance to ozone, UV radiation and cold cracking
• Dimensionally stable
• Limited environmental impact
• Low life-cycle cost
Longest Average Serviceable life: As environmentalists and code regulators place more emphasis on the sustainable performance of building materials, EPDM continues to be the commercial roofing material that stands the test of time. 45 years of empirical experience in field applications has shown EPDM to have the commercial roofing industry’s longest average service life, according to the latest study provided by ERA (EPDM Roofing Association). ERA tested installations 28-32 years of age. The study shows that all of the aged EPDM roof samples taken have physical characteristic properties above or just below the ASTM minimum properties required of newly manufactured 45-mil EPDM membrane, and estimated them to exceed 40+ years of serviceable life.