Cool Metal Roofing. Petersen Aluminum Corporation Elk Grove Village, IL

Transcription

1 Cool Metal Roofing Petersen Aluminum Corporation Elk Grove Village, IL

2 Petersen Aluminum Corporation is a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Copyright Notice This presentation is protected by US and International copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is strictly prohibited.

4 Learning Objectives At the end of this course, you will be able to: Describe how cool metal roofs can reduce cooling energy in a building. Explain the impact cool metal roofs have on lowering peak demand for electricity. Identify ways in which cool metal roofs comply with energy codes and standards. Discuss how cool metal roofs can reduce the environmental burden of a building. Discuss how cool metal roofs can qualify for voluntary programs and incentives.

5 Content The Roofing Market Benefits Energy Principles of cool roofing Research Urban Heat Island Energy Codes/Standards Initiatives Incentives Summary

6 Metal Roofing Market Size Total Roofing Market 278 million squares* Over $30 billion in sales Metal Roofing Market*: 32.5 million squares Residential 16 million squares 10% of total residential market (94% re-roof; 6% new roof) Commercial 16.5 million squares 14% of total commercial market *( 1 square = 100 ft 2 )* Source: Ducker Research, 2008 study

7 Metal Roofing Benefits Aesthetic options Design flexibility High strength-to-weight ratio Class A fire rating Hail resistance Wind resistance Sustainability Durability Platform for rooftop renewable energy

8 Building Boom in U.S. Roughly 89 million new or replacement homes will be built in U.S. over next 30 years to keep up with population growth. By 2030 about half of the buildings in America will have been built after 2000.

9 Energy

10 The USA s Conundrum 2% of the world s resources 5% of the world s population 25% of the world s energy

11 The U.S. Energy Forecast The US primary energy consumption is expected to grow 1.1% annually.

12 By The Year 2030 Our nation s electricity demands will be 45% greater than today. Source: Nuclear Energy Institute

13 Conservation and Efficiency The cheapest, most reliable source of new energy is saved energy. Peter Turnbull, PG&E

14 Roofs and Buildings Buildings are responsible for: Almost 3/4 of nation s electricity consumption. More than 1/3 of total primary energy use.

15 Energy Use in Buildings

16 Why do we care? Sustained growth in building construction is expected. Roof can be least energy efficient and least durable component of a building envelope. Metal s share in roofing is expected to increase. Cool roofing can help to save energy and improve the environment.

17 Cool Metal Roofing Reduce cooling energy use 15-25%. Help reduce peak demand during summer. Help mitigate urban heat island effect.

18 Potential Net Energy Savings

19 40% of raw material use 136 million tons of waste

20 Principles of Cool Roofing

21 Solar Energy Spectrum Ultraviolet (UV) 3% of total energy responsible for sunburn Visible (VIS) 40% of total energy visible light Infrared (IR) 57% of total energy felt as heat!

22 Solar Reflectance (SR) Sometimes called reflectivity. Percentage of all solar radiation reflected from surface. Usually expressed as a decimal. Reflectance of painted metal depends on color and pigmentation. Materials with high SR usually have cooler surface temperature.

23 Thermal Emittance (TE) Sometimes called emissivity. Percentage of absorbed heat energy emitted to night sky. Expressed as a decimal. Thermal emittance of painted metal is high regardless of color. Materials with high TE cool down faster.

24 Energy Balance on Roof Surface Total Solar Radiation Reflected Radiation Re-Emitted Energy Convection Absorbed Energy Roof Surface Layer Net Heat Flux Into Roof

25 Roofing Material Thermal Properties Metal (unpainted) Metal (painted) * Comp Asphalt Shingles Single Ply Membranes Built Up Roofing Modified Bitumen Concrete/Clay Tile * 0.90 * depending on color Solar Reflectance Thermal Emittance Emissivity is generally high in coatings and paint films, but very low in unpainted metallic surfaces Source: ORNL and LBNL

26 HOW DO COOL PAINT SYSTEMS WORK?

27 Traditional Color Theory Dark colors absorb heat energy. Traditional dark roof can be 90 F hotter than ambient. Lighter colors reflect heat energy. Light colored roof can be only 25 F warmer than ambient. But WHY??

28 Paint Technology Pigments give paint its color. Example: Blue paint Special pigments absorb all other colors and reflects the blue wavelengths of light.

29 Cool IR Reflective Pigments Reflect visible light the same as normal pigments. Reflect more infrared energy. Increasing the total solar reflectance (SR).

30 Cool Ceramic Pigments Inorganic or ceramic synthetic materials kiln fired at temperatures exceeding 1500ºF. The resulting molecular structures provide superior sustainable color durability.

31 Pigments in Paint Pigments are inorganic ceramic colored powders Incorporated into paint Applied onto metal substrates Imparting a wide range of colored effects

32 Higher Reflectance with Color White Beige Blue Standard SR.67 Cool SR.72 Standard SR.47 Cool SR.56 Standard SR.21 Cool SR.33 Red Gray Green Bronze Standard SR.25 Standard SR.14 Standard SR.11 Standard SR.08 Cool SR.30 Cool SR.28 Cool SR.28 Cool SR.26

33 Cool paint systems reduce temperature variation on roofing which Minimizes thermal movement. Extends durability of paint system.

34 Case Studies

35 Florida Study Habitat for Humanity Homes: Metal, Shingle, Barrel tile, Terra Cotta tile, Flat tile roofs.

36 Typical Residential Construction in Florida 25% drop in cooling capacity

37 Measured Roof Solar Reflectances Specimen Solar Reflectance (%) Dark gray shingle 8.2 White shingle 24.0 Terra Cotta barrel tile 34.6 White barrel tile 74.2 Flat white tile 77.3 White painted metal 66.2 Off-white metal (original) 55.5

38 Effect of Roofing Material on Attic Temperatures Black Shingle White Metal White Tile Outdoor Air Temp

39 White painted metal roofing saved 23% in cooling energy 30 Savings in Cooling Energy (%) White Shingle Terra Cotta Tile White Barrel Tile White Flat Tile White Metal

40 Urban Heat Island Effect Dark roofing surfaces, parking lots, roads. Less vegetation and shade. Higher ambient air temperature. Urban areas can be 6-12 F warmer. Higher air conditioning loads to cool buildings.

41 Reflectance* of Urban Surfaces * * albedo = solar reflectance

42 Thermal Images of Urban Areas

43 Smog Formation in Urban Areas Heat is a catalyst for smog. 0.5ºF decrease in heat = 5% reduction in smog

44 Energy Codes and Standards

45 Source: Building Code Assistance Project

46 ASHRAE 90.1 Addendum f Modified cool roof provisions. Min aged solar reflectance Min aged thermal emittance

47 IgCC Public version 1.0 Climate Zones 1, 2 & 3. Roof Slope Min Aged Solar Reflectance Min Aged Thermal Emittance Min Aged SRI < 2: :

48 ASHRAE Standard Heat Island Mitigation Climate Zones 1, 2 & 3 Min 75% roof area. SRI 78 for low slope SRI 29 for steep slope OR Comply with Energy Star Program

49 Building Codes Assistance Project

50 Initiatives Most are voluntary. Some are mandatory. Some are self-certified. Some require independent laboratory.

51 Cool Roofing Initiatives California Title 24 CEC Florida White Roof Credit Georgia Energy Code New York Tax Incentive Chicago Urban Island Code Seattle Energy Star Earthcraft ACE 3 CREST DSIRE Federal Energy Bill DOE programs EPA programs Urban Island Group ORNL BTC Captain Planet Zero Energy Millennium Star project ASTM committees ASHRAE committees CRRC Smart School Program Zero Energy Commercial Bldg Initiative

52 Voluntary Programs Energy Star Cool Roof Rating Council LEED Green Globes GreenSpec Green Guard

53 Energy Star Roof Products Program Initiated by EPA in Exterior roof surface is the product. Aimed at roofing manufacturers and suppliers. Numerous paint systems approved.

54 Energy Star Roof Product Program Performance Criteria Initial Solar Aged Solar Roof Slope Reflectance Reflectance Low Slope (< 2:12) Steep Slope (>2:12)

55 Cool Roof Rating Council Established in Non Profit organization. To develop fair, accurate and credible methodology for evaluating and labeling of ALL TYPES of roofing products. Certification system launched August 2002.

56 Cool Roof Rating Council Cool Roof criteria are not defined. Labeling program with SR, TE and SRI. Cost to roofing or coating manufacturer dependent on number of products submitted.

57 Example of CRRC Label Solar Reflectance Thermal Emittance Initial Weathered Pending Pending Rated Product ID Licensed Manufacturer ID Classification XXXX XXXX Production Line Cool Roof Rating Council ratings are determined for a fixed set of conditions, and may not be appropriate for determining seasonal energy performance. The actual effect of solar reflectance and thermal emittance on building construction may vary. Manufacturer of product stipulates that these ratings were determined in accordance with the applicable Cool Roof Rating Council procedures

58 Architecture 2030 Challenge Eliminate fossil-fuel energy consumption from all new buildings by 2030.

59 Zero-Energy Commercial Building Initiative Achieve marketable zero-energy buildings by 2030.

60 Goal To develop and disseminate technologies, practices, and policies for establishment of zero net energy commercial buildings. Major milestones are achieving zero net energy buildings in: New commercial buildings by % of all commercial building stock by % of all commercial buildings by 2050.

61 LEED 2009 Building Certification Program Whole-building approach encourages and guides a collaborative, integrated design and construction process. Four levels of certification pts pts pts 80+ pts

62 Cool Roof Credit Cool metal roof qualifies for one point in Sustainable Site Credit 7.2, Heat Island Effect- Roof. Must cover a minimum of 75% of roof surface area. Requirements (SRI minimum) Roof Type Slope SRI Low slope roof 2:12 78 Steep slope roof > 2:12 29

63 Incentives

64 Statewide Incentives

65 Extended tax incentives related to cool roofing from Energy Policy Act of American Recovery and Reinvestment Act of 2009

66 Tax Credits and Deductions Residential Tax credits to homeowners up to $1,500 for cool prepainted metal roof certified in Energy Star program. Tax credits for contractors up to $2000 for new home energy efficiency criteria. Commercial Tax deductions to owners up to $1.80/ft 2 for energy efficient building criteria.

67 Summary

68 In this presentation, we ve learned that cool metal roofs Are growing in popularity. Can reduce cooling energy in a building. Can lower peak demand for electricity. Can comply with energy codes and standards. Help to reduce the environmental burden of a building. Qualify for voluntary programs and incentives.

69 Thank you Thank you for your time. This concludes the AIA Continuing Education System Program. Please take the test to earn your AIA credits. Questions? I IL: PAC CLAD MD: I TX: GA: I MN: