101 Agenda

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101 Agenda

• What is a Heat Island?
• Science of Cool Roofing
• What is Energy Star Roofing?
• Cool Coatings

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Why is a Heat Island a Problem?

• Hotter temperatures reduce comfort increase
  incidences of heat stress
• Lack of shade leads to more skin cancer risk
• More energy, money pollution expended to run
  air conditioning systems
• Higher energy demand leads to power reliability
  problems, brownouts blackouts
• Air quality worsens since smog forms more readily
  in hotter air
• More smog leads to more respiratory distress

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What does a Heat Island look like?

• Thermal image from NASA June 1998
• Air temperature 24C Wind speed 6 knots
• Rooftops at 54C
• Parking lots 43C

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Effect of Rooftops on Heat Island

• Rooftops are hottest urban features
• 60C to 82C at peak for hottest roofs
• Take up 20 of land area
• Difficult to shade entire rooftops
• Especially large low-slope roofs
• Cool roofing can make a big impact
• 38C to 49C at peak for cool roofs
• 10C drop over 20 of land area!!

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Important Property Definitions

• Solar Reflectivity
• Amount of incoming solar energy a material
  reflects, also called albedo (usually in )
• Emissivity
• Amount of energy a material emits due to its own
  heat and temperature (usually in )

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Typical Solar Reflectivities
The coolest materials reflect the suns energy
over all wavelengths
Solar Reflectivity 5 15 25
75 or Albedo black green grey
white
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Typical Emissivities

• Most materials have emissivities of at least 90
• Metals are the exception
• Emissivities vary widely between 20 and 60,
  depending on surface condition
• Low enough to keep metals hot, despite their high
  reflectivity

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Effect of Reflectivity Emissivity on Roof
Temperature
To be cool, a roof must have both
high reflectivity high emissivity
hottest
hot
cool
black asphalt aluminum coating
white coating low reflectivity
high reflectivity very high
reflectivity high emissivity low
emissivity high emissivity
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White Coating on a Light Gray Capsheet Roof

• Surface temperature reduced from 71C to 38C

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One Week of Roof Temperatures

• Uncoated values calculated from measured data
• Peak temperature reductions of 30 to 60F

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One Week of Cooling Energy Use
Totals 3242 kWh coated 4102 kWh
uncoated Savings 860
kWh or 21
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Building OwnerBenefits from Cool Roofing

• Cooling energy savings of 20
• Better building comfort
• Longer life of cooler roofing products
• Protected from UV thermal degradation
• Lower life-cycle costs
• First costs are often lower, too
• Cooling equipment lasts longer
• Potential to downsize new equipment

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Community Benefits from Cool Roofing

• Cooler rooftops reduce heat island effect
• Air quality improvements
• Air pollution reduction from less energy
  production and less smog from cooler air
• Reduced roofing waste into landfills
• 11 million tons per year, 7 to 10 of landfill
  space over the last 40 years
• Improved power reliability
• Reduced electricity demand at peak

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Smog is created by photochemical reactions of
pollutants in the air. This action intensifies at
higher temperatures. In Los Angeles, for example,
for every degree Fahrenheit the temperature rises
above 21ºC, the incidence of smog increases by 3.
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What is Energy Star Roofing?

• US Environmental Protection Agency
• Program to label consumer products and appliances
• Top energy saving products save energy money
  and reduce pollution

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Energy Star for Low-Slope Roofs

• Mostly for commercial/industrial market
• Initial Solar Reflectance
• Greater than or equal to 0.65
• Maintenance of Solar Reflectance
• Greater than or equal to 0.50 three years after
  installation under normal conditions
• Manufacturer warranty
• for defects in materials manufacturing, equal
  to the warranty offered for comparable
  non-reflective roof products

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Charter Partner Energy Star Roof Products Program

• UNITEDS roofing systems have been independently
  tested and certified to exceed the ENERGY STAR
  guidelines for energy efficiency

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• 100 Acrylic Polymers
• Aquathon Ceramic is manufactured exclusively
  using 100 acrylic polymers. The result is a
  tight, cross-linked finish that retains its
  physical properties to provide maximum
  reflectivity, long-term weather resistance, UV
  and color stability, mildew resistance and dirt
  repellency

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Aquathon CR reflects over 85 of the suns
radiant heat

• Lowers roof temperatures up to 70

• Radiant heat is reflected not absorbed

• Interior temperatures are reduced

• Saves energy associated with extended
• air conditioning use

• Extends roof life

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• Many Buildings Would Benefit From Additional
  Insulation
• Not All Roof Substrates Are Candidates For A
  Coatings Only System
• SPF Is An Excellent Way To Seal And Insulate Duct
  Work

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Protecting Your Roof Using a Highly Reflective
Roof Coating

• Reduces UV damage
• Reduces thermal shock
• Protects against leaks

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• SAVE ENERGY
• SAVE MONEY
• SAVE YOUR ROOF

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COAT IT