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APWA Cool Roofing Made Simple

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APWA Cool Roofing Made Simple

  1. 1. Cool Roofing Made Simple Program #037 CO
  2. 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. 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
  4. 4. What Is Cool Roofing?
  5. 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. 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. 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. 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. 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. 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. 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)
  12. 12. Who Sets The Standards For Cool Roofing?
  13. 13. Who Sets The Standards For Cool Roofing •  ENERGY STAR® •  CRRC (Cool Roof Rating Council) •  LEED® (Leadership in Energy & Environmental Design) •  Title 24
  14. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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)
  30. 30. How Cool Roofs Create Energy Savings
  31. 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
  32. 32. Cool Roof Energy Savings
  33. 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
  34. 34. Other Benefits Of Cool Roofing
  35. 35. Other Cool Roof Benefits •  Decreased Roof Maintenance •  Reduced Impact on Surrounding Air Temperatures •  Reduced Peak Electricity Demands •  Higher Overall Interior Building Comfort Level
  36. 36. Decreased Roof Maintenance •  Slows The Aging Affects Of Sun Light On The Roof •  Reduces The Expansion And Contraction Of The Roof System
  37. 37. Reduced Impact On Surrounding Air Temperatures
  38. 38. Thermal Map of Tallahassee, Florida
  39. 39. Industry Options For Cool Roof Solutions
  40. 40. 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
  41. 41. 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
  42. 42. High-Performance Metal Roof System •  Properties To Look For –  Low Life-Cycle Cost –  Recyclable Material –  Use On Multiple Slopes –  Lightweight –  Allows For Movement
  43. 43. 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)
  44. 44. 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 $ $)!
  45. 45. 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
  46. 46. Energy Calculators •  Estimate AC Energy Savings (and Wintertime Penalty) From Cool Roofs – EPA – ORNL – LBNL – National Coatings Corp R.E.S.T Program
  47. 47. 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
  48. 48. Conclusion Coatings Can Provide: •  Extended Durability •  Improved Water Resistance of The Roof Assembly •  Lower Life-Cycle Costs (LCC)
  49. 49. Thank You

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