2. Today’s Agenda
• What is Cool Roofing?
• Who Sets the Standards for Cool Roofing?
• Cool Roofs Create Energy Savings
• Other Benefits of Cool Roofing
• Question/Answer session
• Course Evaluation
3. Learning Objectives
• Define Cool Roof Systems
• Describe How Cool Roofs Prevent Sun-Related
Damage, Increase Roof Life and Help Cut Energy
Costs
• Identify Criteria Used by Organizations Such as
ENERGY STAR®, the Cool Roof Rating Council,
LEED® and Title 24 to Evaluate the Performance
Standards of Cool Roofs
• Describe Various Industry Options Available
For Cool Roof Solutions
5. What Is A Cool Roof?
• Cool Roofs Absorb Less Than 35% Of Solar Energy
Striking The Roof
• Compared To Traditional Dark Roofs Absorbing
70% Or More Of The Solar Energy
• Results In Reduced Heat Transfer Into Building,
Reducing Energy Costs And Thermal Expansion
Of The Building Envelope
6. Characteristics of
Cool Roofing Materials
• To Be “Cool,” A Roof Must Keep Out
(Reflective Energy) A High Percentage
Of The Solar Heat Hitting It And Let Out
(Emissive Energy) A High Percentage
Of The Heat It Absorbs
Roof
Reflected
Energy
Emitted
Energy
7. What Is Reflectance?
• Reflectance – Straightforward – Sun’s
Energy (Heat) Bouncing Off Roof Surface
and Not Being Absorbed
• Different Materials Will Have A Higher or
Lower SR (Solar Reflectance) Number
• “Reflectance” Is a Measure of How Much or
How Little of The Sun’s Heat Is Absorbed
Into the Surface
8. What Is Emittance?
• Emittance – Not ALL Energy Bounces Off;
Some Is Absorbed. Absorbed Energy Is
Given Off – Emitted – At Different Rates By
Different Materials
• “Emittance” Is A Measure Of How Quickly or
Efficiently The Absorbed Energy Is Given Off
– Important Because Slowly Emitted Heat Has
Time To Penetrate Downward Into The Building
9. Characteristics of
Cool Roofing Materials
• Solar Reflectivity, Emissive Energy
And Roof Temperature
40%
Roof 160°FRoof 180°F Roof 100°F
60%
90%
80%
95% 5%
Black Asphalt
• Low Reflectivity
• High Emissive
Energy
Aluminum Coating
• High Reflectivity
• Low Emissive
Energy
White Coating
• Very High
Reflectivity
• High
Emissive
Energy
10. How Cool is Cool?
Sacramento, CA - July 12, 2000
89º F (31.6º F) , About Noon, With Local Delta Breeze
EPDM
Single-Ply
173°F (78.3°C)
BUR Topped
with Standard Cap
158 °F (70°C)
BUR Topped
with Aggregate
159°F (70.6°C)
11. How Cool Is Cool?
Sacramento, CA - July 12, 2000
89ºF (31.7ºC) Noon Delta Breeze
Cool Coating Over BUR
108°F (42.2°C)
Cool Single-Ply
121°F (49.4°C)
13. Who Sets The Standards
For Cool Roofing
• ENERGY STAR®
• CRRC (Cool Roof Rating Council)
• LEED® (Leadership in Energy &
Environmental Design)
• Title 24
14. ENERGYSTAR®
Roofing Criteria
• ENERGY STAR is a Joint Program of The
U.S. Environmental Protection Agency and
The U.S. Department of Energy Helping Us
All Save Money and Protect The
Environment Through Energy Efficient
Products and Practices
– In 1992 The EPA Introduced Energy Star as a
Voluntary Labeling Program Designed To Identify
And Promote Energy-Efficient Products To Reduce
Greenhouse Gas Emissions
• ENERGY STAR is Not Title 24
– An ENERGY STAR Roof Does Not Automatically
Qualify as a Cool Roof In California
15. Note: Emissive Energy Not Part of EPA ENERGYSTAR® Criteria
ENERGYSTAR®
Roofing Criteria
• Low Slope Assemblies
– Most Commercial
Buildings
– Less Than 2:12 Slope
– Initial Reflectance Must
Be 65% Or Higher
– After 3 Years,
Reflectivity Must Be
Greater Than 50%
• High Slope Roofing
– Most Residential
Buildings
– Greater Than 2:12
Slope
– Initial Reflectance Of
25% Or Higher
– After 3 Years,
Reflectivity Must Be
Greater Than 15%
16. Cool Roof Rating Council
• The Cool Roof Rating Council Was Created In
1998 To Develop Methods For Evaluating and
Labeling Solar Reflectance & Emittance of
Roofing Products
– The CRRC’s Product Rating Program
• Reports Solar Reflectance and Thermal Emittance
• Has Random Sampling To Monitor Compliance with
Label Claims
• Official Ratings Achieved Through CRRC
• Independent Accredited Testing Laboratories
• Tests Short Term And Long Term Results
• Test Products Through ASTM Testing Procedures
17. Cool Roof Rating Council
• All Radiative Property Testing is Conducted by
Accredited Testing Laboratories
• Solar Reflectance Measured in Accordance
with ASTM Test Methods C1549, E1918, E903
and CRRC-1 Method #1: Test Method for
Certain Variegated Products
• Thermal Emittance Is Measured in Accordance
With ASTM C1371
• For Aged Ratings, Product Samples Are
Exposed for Three Years at the CRRC
Approved Test Farm
• Product Ratings Are Verified Periodically
Through CRRC's Random Testing Program
18. Cool Roof Rating Council
• Mission: “Implement and Communicate Fair,
Accurate, and Credible Radiative Energy
Performance Rating Systems for Roof Surfaces”
• Membership: Roofing Manufacturers, Suppliers,
Distributors, Contractors, Consultants, Non-Profit
Groups, Government Agencies, Educational
Institutions, Air Quality Boards, Code Bodies,
Energy Service Companies and Other Interested
Individuals
• Committees: Board Of Directors
• Subcommittees or Task Forces to Work on Individual
Projects
• 172 Manufactures Listed on The Web Site
(as of June 2010)
19. USGBC LEED® Program
• “LEED is a Third-Party Certification
Program and the Nationally Accepted
Benchmark for the Design, Construction
and Operation of High-Performance Green
Buildings”
20. USGBC LEED Program
• SS Credit 7.2: Heat Island Reduction: Roof
– 1 Point Based on the Following:
• Option A: Roofing Material Using Solar Reflectance Index (SRI)
=/< 78 (Low Slop); 29 (Steep Slop) on 75% of Roof Area
(Minimum)
• Option B: Vegetated Roof Covering 50% of Roof Area
(Minimum)
• Option C: High SRI Roofing Material and Vegetated Combined
Make Up 80% of Total Roof Area
21. Testing Standards
• SRI is Calculated to ASTM E 1980
• Reflectance is Measured to ASTM E 903,
ASTM E 1918 or ASTM C 1549
• Emittance is Measured to ASTM E 408 or
ASTM C 1371
22. USGBC LEED Program
• SS Credit 6: Storm water Management
– 1 Point Based on the Following:
• Storm water Management Plan that Infiltrates,
Collects and Reuses Runoff or Evapotranspirates
Runoff from at Least 15% of the Precipitation
– Vegetated Roofs
23. USGBC LEED Program
• EA Credit 4.1-4.4: On-Site and Off-Site Renewable
Energy
– 1-4 Points Based on the Following:
• 3% On-Site or 25% Off-Site Renewable Energy = 1 Point
• 6% On-Site or 50% Off-Site Renewable Energy = 2 Point
• 9% On-Site or 75% Off-Site Renewable Energy = 3 Point
• 12% On-Site or 100% Off-Site Renewable Energy = 4
Point
– Solar, Geothermal, Wind, Biomass, and Biogas Technologies
24. Estimated Value of New LEED For New
Construction Registered Projects
The Value of U.S. Construction
Starts Significantly Declined By
Almost Half From 2000 To 2003
2000 2001 2002 2003 2004
$792 MILLION
$3.24 BILLION
$3.81 BILLION
$5.76 BILLION
$7.73 BILLION
2006
$10
BILLION
$200 BILLION
PROJECTED
25. LEED For New
Construction Buildings
Distribution
by Geography
1-19
20-49
50-99
100-199
200+
9
4
911
11
69
125
2582
40
28 14
8
134
186
480
22
23
57
19
6
6
18
73
102
22
11
19
120
79
11936
52
74
95
173
174
33
105
61 27
12
9 (DE) 38 (DC)
23 (DE)
24 (NH)
5 (OK)
4
68AK=10
HI=16
PR=1
as of 07/06
26. Title 24, Part 6, California’s
Energy Code: How It Works
• Sets An Energy Budget For Residential
And Non-Residential Buildings
– New Buildings And Additions/Alterations
(Alterations Can Include Re-Roofing)
– Budget Is In kBtu/Square Foot/Year
– Budget Varies By Climate Zone
• 16 Climate Zones In California
27. Climate
Zone 1,
Coastal,
Foggy
Most Of
Year
Climate Zone
16 – Mountains,
Snows In
Winter, Less
Than 80°F In
Summer
Many Inland
Climate Zones
– Mild Winters,
Hot Dry
Summers
(Population
Increasing Most, Air
Conditioning Needs
Increasing)
Title 24, Part 6
28. Title 24, Part 6: Regulates
• The Efficiency of:
– Lighting
– Windows, Doors, Skylights
– Water Heating Systems
– Space Heating and Cooling Systems
– Insulation Levels In Walls, Floors, and Ceilings/Attics/
Roofs
– Tightness Of Air Ducts
– Allowed Square Footage of Windows, Doors,
and Skylights
29. What Is A Cool Roof Under California’s Title
24 Energy Standards?
• Be Rated Through Cool Roof Rating Council
(Title 24, Part 1)
• Be Properly Labeled (Title 24, Part 1)
• Have Reflectance ≥ 0.70 and Emittance ≥ 0.75
(or If Emittance Is Lower, Need Higher
Reflectance) (Part 6, and 2)
• For Coatings Liquid-Applied In The Field, Meet
Performance Requirements (Part 6)
31. Cool Roof Energy Savings
• ENERGYSTAR® Roofing Products Can
Reduce Overall Energy Cost By 50% and
Peek Cooling Demand By 10-15%
– A Study Funded By The EPA, Found That Cool
Roof Buildings In Sacramento, CA Used Up To
40% Less Energy Than Buildings With Dark
Roofs
– A Study Conducted By The Florida Solar Energy
Center Found That Increasing The Thermal
Reflectance From 23% To 68% Equated Into a
35% Reduction In Peak Electrical Demand of
The Cooling System
33. Cool Roof Energy Savings
• By Comparison, a White, Reflective Cool
Roof Will Be 50°F To 60 °F (10°C -15.6°C)
Cooler on Hot Days
• The Resulting Reduction of Heat Transfer
Into The Air-Conditioned Spaces Below Can
Decrease Cooling Costs By 10-15% On
Average
41. High Performance
BUR & Modified Coating
• Properties To Look For
– Asphalt Bleed Through Resistance To Maintain
Aesthetic and Reflectance Values
– Environmentally Friendly
– Ease of Application
– High Elongation
• The Amount of Stretching Before It Ruptures
– Fungi/Mold Resistant Coating
• Safe and Maintains Aesthetics
– ENERGY STAR Compliant
42. High Performance
Single-Ply Restoration
• Properties To Look For
– Very High Tensile
• Determines The Coatings Ability To Resist Thermal
Movement
• High Elongation
– High Impact Resistance
• Function of Tensile Strength and Elongation
– High Bond Strength
• Force To Separate Coating From Substrate
– ENERGY STAR Compliant
43. High-Performance
Metal Roof System
• Properties To Look For
– Low Life-Cycle Cost
– Recyclable Material
– Use On Multiple Slopes
– Lightweight
– Allows For Movement
44. High-Performance
Metal Roof Restoration
• Properties To Look For
– Superior Expansion and Recovery Capability
– Self Priming
• Elimination of Costly Steps
– Superior Adhesion
• Must Adhere Well To Smooth Sub Straight
– Cold Weather Capability
– ENERGY STAR Compliant (White Only)
45. Prolonging Roof Life
• Roofs Wear Out Because Of
– Sunlight
• Heat
• UV
– Freeze/Thaw
– Roof Deck Movement
– Oxygen
– Precipitation
• It Is More Cost Effective To Maintain Rather
Than To Repair Or Replace (Read: BIG $
$)!
46. A Successful Roof Coating
Must:
• Block UV
– Protect Itself and The Membrane
• Keep The Membrane Cooler
• Act As Water/Weather Barrier
• Prevent Egress of Light Asphalt Fractions/
Plasticizers
• Low Temperature Flexibility
• Dirt Pickup Resistant
• Adhesion To Roof Surface
• Expand and Contract With Roof
47. Energy Calculators
• Estimate AC Energy Savings (and
Wintertime Penalty) From Cool Roofs
– EPA
– ORNL
– LBNL
– National Coatings Corp R.E.S.T Program
48. Conclusion Coatings
Can Provide:
• Reduce “Heat Islands”
• Reduce Ambient Air Temperature
• Reduce Energy Costs
• Improve Air Quality
• Lower CO2 Emissions
– Every kWh Of Electricity Generated Creates 1.46 lbs.
Of CO2
• Extend Roof Life
