Sustainable Design -Ideas using Metal Roofing

Drexel Metals is a Registered Provider with the American Institute of Architects ContinuingEducation Systems. Credit earned on completion of this program will bereported 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 anapproval or endorsement by the AIA of any material of construction or any methodor manner of handling, using, distributing, or dealing in any material or product.Questions related to specific materials , methods, and services will be addressedat the conclusion of this presentation.

Did you know?

The built environment has a profound impact on our natural environment, economy, health and productivity.

• In the United States, buildings account for: – 36% of total energy use/65% of electricity consumption.– 30% of greenhouse gas emissions – 30% of raw materials use – 30% of waste output/136 million tons annually – 12% of potable water consumption

Now what?

• Design buildings that:– Reduce Carbon Emissions/Footprint– Help to reduce Urban Heat Island– Help to Reduce Peak Energy Demand– Include Sustainable materials– Ensure you can monitor Performance using Green

products.

Metal Roofing

COOL METAL ROOFINGHow it works!

What is Cool Metal Roofing?

Metal Roofing is CoolCool metal roofing is a family of sustainable,

energy efficient roofing products comprised of unpainted metal and prepainted metal.

It is available in a wide variety of finishes, colors, textures, and profiles for steep-slope and low-slope applications.

How Cool Metal Roofs works

Solar Reflectance

Emmitance

Same technology as the Stealth Bomber

Cool Metal Roofing is Highly Reflective – using Pigment Technology Metal roofing meets the EPA Energy Star Roof Products Program performance criteria. Metal

roofing is also eligible for other cool roof incentive programs.

Cool Metal Roof Vocabulary

Reflectivity – a measure of the portion of solar radiation that is reflected away from a surface

Emissivity - the capacity of a body to re-emit infrared energy that has already been absorbed

TSR = Total Solar ReflectanceTSR = Total Solar Reflectance

TE = Thermal EmittanceTE = Thermal Emittance

TSR=0.70

TE=0.87

TSR=0.26

TE=0.87

TSR=0.26

TE=0.87

TSR=0.29

TE=0.84

TSR=0.26

TE=0.87

TSR=0.67

TE=0.87

Reflects 70% Suns Heat Energy Absorbs 30% of Suns Heat Energy

New IR Pigments = Less Heat = Energy Savings

SR = 14% SR = 26%

GA School board saves!

• Two identical buildings with same exposure, no shading.

• Thermostat control at board office.• Only One variable: • Both schools used same color: Forest Green

– One roof has a TSR of 12% –– One roof has TSR of 29% – energy star approved. – NET SAVINGS: $ 8200.00 per year– Expected life of the roof – 45 years – – Realized savings of $ 369,000 over its useful life with no

required maintenance to the roof!

Reduce Urban Heat Island!

Life ExpectancyBased on a study conducted by Ducker in 2003, metal

roofs have a significantly longer expected service life than either asphalt or single-ply roofs. According to Ducker findings, metal roofs are expected to last 17 years longer than asphalt and 20 years longer than single-ply.

Expected Roof Life Years • Metal: 40• Asphalt:23• Single-ply:20Due to its credible long life and documented durability,

metal roofing makes an attractive investment.

Energy Performance

Life Cycle

Life Cycle Cost

• According to Ducker’s 2004 research study, the life cycle cost of a metal roof is significantly less than an asphalt or single-ply roof.

• The expected life cycle cost of metal roofs reported in this study is 30 cents per square foot per year, asphalt is 37 cents per square foot per year, and single-ply roofs is 57 cents per square foot per year.

Little to no maintenance

Little to no Maintenance

Other Cool Roofing facts• Cool Metal Roofing is Very Durable

– Metal roofs are credibly proven to last over 30 years with minimal maintenance. Metal roofs are documented to resist wind, hail, fire, and earthquakes. Painted metal roofs retain 95% of their initial reflectance and emittance over time.

• Cool Metal Roofing has Recycled Content and is Recyclable– Metal roofs typically have a minimum recycled content of 25%.

Metal roofs are 100% recyclable at the end of a long, useful life.

• Cool Metal Roofing is Aesthetically Pleasing– Metal roofing is available in a wide range of finishes, colors and

profiles, giving architects extensive design flexibility.

Metal Roofing and LEED

USGBCThe U.S. Green Building Council (USGBC) is the nation’s foremost coalition of leaders from

every sector of the building industry working to promote buildings that are environmentally responsible, profitable and healthy places to live and work.

• Leadership in Energy and Environmental Design (LEED)– Green Building Rating System™ is the nationally accepted benchmark for the

design, construction, and operation of high performance green buildings. – LEED gives building owners and operators the tools they need to have an

immediate and measurable impact on their buildings’ performance. – LEED promotes a whole-building approach to sustainability by recognizing

performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.

How can cool metal roofing qualify in LEED?

Click to update SRI

Cool metal roofing can qualify for 1 point within LEED-NC Version 2.2, Sustainable Sites Credit 7.2, Heat Island Effect: Roofing by using roofing materials that have an Solar Reflective Index (SRI) rating minimum of 78 for low sloped roofs (≤ 2:12) or a minimum of 29 for steep slope (> 2:12).

To see if your cool metal roofing product can achieve the SRI minimum number, visit the LBNL SRI Calculator. You’ll need to know the Solar Reflectance and Thermal Remittance number to obtain the SRI value. Download SRI calculator.

• Materials & Resources– MR Credit 1.1 Building Reuse: Maintain 75% of Existing Walls, Floors & Roof– MR Credit 1.2 Building Reuse: Maintain 95% of Existing Walls, Floors & Roof

(When a building is renovated for reuse, existing metal roofing can qualify.)

– MR Credit 2.1 Construction Waste Management: Divert 50% from Disposal– MR Credit 2.2 Construction Waste Management: Divert 75% from Disposal

(When a building is demolished, existing metal roofing is easily recyclable.)

– MR Credit 3.1 Materials Reuse: 5%– MR Credit 3.2 Materials Reuse: 10%

(When a building is demolished, existing metal roofing might be reused.)

– MR Credit 4.1 Recycled Content: 10% (post-consumer + ½ pre-consumer)– MR Credit 4.2 Recycled Content: 20% (post-consumer + ½ pre-consumer)

(See “Steel Takes LEED With Recycled Content” at www.recycle-steel.org)

LEED POINTS - METAL ROOFING

LEED POINTS - METAL ROOFING

• Sustainable Sites– SS Credit 7.2 Heat Island Effect: Roof

(Selected painted metal roofing can meet the solar reflective index value.)

• Water Efficiency– WE Credit 1.1 Water Efficient Landscaping: Reduce by 50%– WE Credit 1.2 Water Efficient Landscaping: No Potable Water Use or No Irrigation– WE Credit 2 Innovative Wastewater Technologies– WE Credit 3.1 Water Use Reduction: 20% Reduction– WE Credit 3.2 Water Use Reduction: 30% Reduction(Metal roofing can easily be applied to captured rainwater systems for building use.)

LEED POINTS – METAL ROOFING

• Energy & Atmosphere– EA Credit 1 Optimize Energy Performance

(Cool metal roofing can be modeled to show the impact of reduced heat gains.)

• Indoor Environmental Quality(Metal roofing can help ventilation and day lighting and provide low VOC substrates.)

• Innovation in Design– RENEWABLE ENERGY CREDITS

Metal Roofing and Solar

What Does a 100kW PV System Mean?

SUNRISE SUNSET

•As the sun rises the photovoltaic cells begin to produce electricity at a low level

•At noon a 100kW system is producing at its optimum output

•In California the average 5 peak sun hours a day

•Therefore, we could say that this 100kW system produces 500kWh/day (100kW x 5 hours = 500kWh)

•Depending on your energy usage profile a 100kw system could produce all or part of your total energy needs

System Design

Net Metering• Under State NET METERING agreements The PV power is

connected to run your meter backwards with the energy you produce.

• The local utility and the third party monitoring company track each kwhr your system produces

• Credits are issued monthly by the utility for energy produced• Credits cannot exceed your historical usage annually.• Performance based incentives are monitored and paid to the

system owner utilizing this process.

Cash Flow and Breakeven

How is the Energy Production Monitored?• Third party companies provide web based real time monitoring capability.

• Service cost is integrated into project O&M cost.

Full System Design

One Step Further

Thermal System using Copper SS

METAL ROOFING, SOLAR AND THERMAL HOT WATER USING HEAT TRANSFER

Solar Monitoring

In the Press

Questions?Comments?Concerns ?