apwa cool roofing made simple

Cool Roofing Made Simple

Program #037 CO

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

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

What Is Cool Roofing?

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

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

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

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

Characteristics of Cool Roofing Materials •  Solar Reflectivity, Emissive Energy

And Roof Temperature

40%

Roof 160°F Roof 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

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)

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)

Who Sets The Standards For Cool Roofing?

Who Sets The Standards For Cool Roofing •  ENERGY STAR®

•  CRRC (Cool Roof Rating Council) •  LEED® (Leadership in Energy &

Environmental Design) •  Title 24

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

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%

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

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

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)

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”

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

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

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

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

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

LEED For New Construction Buildings

Distribution by Geography

1-19 20-49 50-99 100-199 200+

9 4

9 11 11

69

125 25 82

40 28 14

8

134

186 480

22

23

57

19

6 6

18

73

102 22 11

19

120 79

119 36

52

74

95

173

174 33 105

61 27 12

9 (DE) 38 (DC)

23 (DE) 24 (NH)

5 (OK)

4

68 AK=10 HI=16 PR=1

as of 07/06

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

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

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

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)

How Cool Roofs Create Energy

Savings

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

Cool Roof Energy Savings

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

Other Benefits Of Cool Roofing

Other Cool Roof Benefits •  Decreased Roof

Maintenance •  Reduced Impact on

Surrounding Air Temperatures

•  Reduced Peak Electricity Demands

•  Higher Overall Interior Building Comfort Level

Decreased Roof Maintenance •  Slows The Aging

Affects Of Sun Light On The Roof

•  Reduces The Expansion And Contraction Of The Roof System

Reduced Impact On Surrounding Air Temperatures

Thermal Map of Tallahassee, Florida

Industry Options For Cool

Roof Solutions

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

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

High-Performance Metal Roof System •  Properties To Look For

–  Low Life-Cycle Cost – Recyclable Material – Use On Multiple Slopes –  Lightweight – Allows For Movement

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)

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 $$)!

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

Energy Calculators

•  Estimate AC Energy Savings (and Wintertime Penalty) From Cool Roofs – EPA – ORNL – LBNL – National Coatings Corp R.E.S.T Program

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

Conclusion Coatings Can Provide: •  Extended Durability •  Improved Water Resistance of The Roof

Assembly •  Lower Life-Cycle Costs (LCC)

Thank You