StLouis Renewable Energy: White Roofs Can Cool Urban Temperatures
Showing posts with label White Roofs Can Cool Urban Temperatures. Show all posts
Showing posts with label White Roofs Can Cool Urban Temperatures. Show all posts

StLouis White TPO Roof Project CAD Detail

StLouis, MO St. Louis, MO, USA Links to this post
CAD Detail No: 9821 White TPO Flat Roof Replacement Detail using Structodeck.

Eco Friendly White TPO Roof Job Site Project Photos bottom of page

CAD Detail White Roof Install Masonry Building StLouis Investment Property
CAD Detail No: 9821 White TPO Flat Roof Replacement Detail using Structodeck
  • I've found that making a simple and quick graphic image to use as a visual tool to explain a building system repair to a client is easier when I provide a "non technical" image of the proposed work to be done.
  • Why GAF EverGuard® TPO
    • Outperforms standard TPO in heat aging and UV tests—the best predictors of TPO performance
      - Independent TPO Study proves EverGuard® TPO 60 mil Membrane is the best standard TPO in accelerated aging. View the key findings and full study here.
      - After accelerated heat aging at 275°F (135°C) for 112 days, EverGuard® TPO showed no cracking—while every one of the competitors’ samples had failed!
      - UV testing—Greater than 2.5 times the industry standard (ASTM D6878 weather resistance test)
    • Guarantees are available up to 25 years when using EverGuard® TPO 60 mil Membrane.*
    • Easier to install due to:
      - Large welding window
      - Most complete line of accessories
      - 10' (3.05 m) wide sheets

  • DESCRIPTION STRUCTODEK HD is not only an integral roofing system component; it also makes roofing easier with physical properties that generate structural rigidity and dimensional stability. The wood fiberboard composition of STRUCTODEK HD possesses natural bonding qualities, resulting in superior adhesion capabilities. Adhesive tightly grasps the fibers of STRUCTODEK HD without causing excess absorption, providing a solid and secure roof system which bonds very well with many asphalt, coal tar, and cold-process adhesive products. The lightweight nature of STRUCTODEK HD is better than heavier alternatives and will keep the roof load below the specified maximum weight. Source

  • Below Porch photo prior jobsite building photo - barrel tile roof removal replaced with asphalt shingles.

    Kevin at Travis Roofing Supply was a great help in outlining the proper materials and needed prep to ensure the TPO roofing will meet and exceed the expectations of the Investment Property Owner plus the 25 year product guarranty. 

    Below are the project photos for the TPO white roof Project

    Travis Roofing Supply is located just north of the Vandeventer/44 in the old RSG Roofing Building 

    Thank You for stopping by the Green Blog. If additional information in needed or you have a question let me know by posting a question or comment. Together we can make a difference and create a future that will benefit everyone.

    Roof System-Generates Clean Photovoltaic Energy

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    If you are considering a new roof, you should consider a white roof and a solar system on that roof at the same time. A cool roof reduces building cooling requirements by lowering the temperature of the roof and the building underneath. This means cooling equipment savings and in many cases the ability to run less air conditioning or purchase smaller air conditioning units.

    You may even increase the life of your roof. By lowering the roof temperature, roofing products may last longer due to less thermal stress over time. Our non-penetrating design means less opportunity for leaks from your new roof.

    While it makes great economic sense, a cool roof also makes an important statement about your commitment to reducing your building’s impact on the environment.  One clear environment benefit comes as cool roofs reduce the “heat island” effect in cities, lowering average outside air temperatures. Lower the outside air temperature and you need even less cooling. In fact, U.S. Energy Secretary, Steven Chu said that “whitening the world’s roofs and roads would have the same effect on global warming as removing all the world’s cars for 11 years.”

    Find Photos and Additional Information on Cool Roofing Systems at: Scott's Contracting Web Site

    Cool Roofs-Materials, Options, Insulation, Photos

    StLouis, MO St Louis, MO 63109, USA Links to this post

    Cool Roofs for Hot Climates

    Lighten the loads on home air conditioners with reflective roofing, radiant barriers, or better insulation and ventilation

    Steven Spencer, FSEC

    Even in hot, sunny climates, it's common to see dark shingle roofs. That heat-absorbing choice carries a significant energy penalty: In sunny climates, heat gain through the roof makes up a major share of a house's cooling load.

    People try different strategies to limit heat gain through the roof. Extra ceiling insulation, extra ventilation, under-roof radiant barriers, and sealed attics with insulated roof decks can all help in certain circumstances. But research shows that the single most effective way to cut the cooling loads from a hot-climate roof is to make the roof reflective. There's a reason all those quaint little cottages in Bermuda have white roofs -- they work.

    Reflective roofs work because they stop the rooftop heat before it ever gets going. The sun's rays hit the roof at the speed of light, and at the speed of light they bounce back into space. White or light-colored materials work best, but some new dark pigments reflect enough invisible infrared radiation to reject a lot of solar energy. And whether you're applying tile, metal, membranes, or even asphalt shingles, choosing a more reflective version seldom adds cost.

    Let's look first at reflective roofs, then consider some of the other options for cutting heat gain through the roof.

    Reflective Roofing
    It's well established that reflective roofing materials can lighten the load on home air conditioners. When researchers at the Florida Solar Energy Center (FSEC), where I am a principal scientist, whitened the roofs of nine occupied homes in the summer of 1994, air-conditioning savings averaged 19%. We got even better information by comparing seven otherwise identical new homes with various roof types in a study sponsored by Florida Power & Light (FPL) during the summer of 2000 (see Figure 1). All these homes had R-19 ceiling insulation, but each had a different roof covering. Clearly, reflective roofing made a huge difference.

    Reflective Roof Savings
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    Figure 1. Florida Solar Energy Center researchers compared the air-conditioning power use of seven identically built houses with different roof coverings. Reflective roofing dramatically reduced total power use (bottom chart) and had an even greater effect on peak A/C power demand (middle chart). Insulating the roof deck and sealing the attic, without using a reflective roof, cut total energy use somewhat but did not reduce peak cooling loads noticeably.

    One house of the seven had an insulated roof deck, to keep the ductwork within the sealed, conditioned attic. That modification did save energy on average, but not as much as the reflective roofs -- and it had little effect on peak loads.

    Cool colors. Until recently, a roof had to be white to have high solar reflectance -- something not every customer wants. But we now have tile and metal roofing systems made with "spectrally selective" paints, which absorb some colors of light in the visible range but reflect rays in the infrared and ultraviolet spectra that account for much of the sun's heat. These colors give designers more choices, while still saving considerable energy (Figure 2).

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    Figure 2. Kynar roof coatings using spectrally selective pigments from Ferro Corporation allow Classic Roofs to produce aluminum and steel shingles in several dark colors that meet Energy Star minimums with solar reflectances better than white asphalt shingles. Tests indicate that the colors will sharply reduce solar heat gain through the roof.

    BASF Corporation's ULTRA-Cool metal-roof coatings (800/669-2273,, which use spectrally selective pigments from Ferro Corporation (216/641-8580,, have a 38% reflectivity in colors that achieve only 25% reflectivity when made with standard pigments. And at least two companies, Classic Products (800/543-8938, and MCA Tile (800/736-6221, now supply metal or clay tile in a range of colors with solar reflectance around 30%. Classic's "Musket Brown," for instance, reflects 31% -- quite a bit better than a white shingle -- while the same color in traditional paint would reflect only 8%.

    Bare metal roofs. Unfinished galvanized or "tin" roofs are still fairly common in the hot Southeast. Galvanized steel is highly reflective when new, but its reflectivity soon drops as the zinc oxidizes; and the material also has low infrared emittance. The high absorptance and low emittance can combine to keep the roof blazing hot.

    When FSEC researchers put a white coating on the ten-year-old galvanized steel roof of a retail strip mall, the roof's reflectance went from 30% to 77%. The average air-conditioning reduction in seven monitored shops was more than 24% (Figure 3).

    Figure 3. Unfinished galvanized steel roofs may look shiny when new, but they age quickly to become very nonreflective. The infrared thermal scan (top) shows the drop ceiling (middle) at a radiant temperature of almost 90°F under the metal roof of a strip mall building, despite insulation below the roofing. When FSEC researchers applied a reflective coating (bottom), the building's air-conditioning power use dropped 16%, and tenants reported improved comfort. One tenant even called to thank the landlord for fixing the air conditioner. (He hadn't.)

    If you want unfinished metal roofing, Galvalume (an alloy of aluminum and zinc) is a much better cool-roof choice than galvanized steel, especially in mixed heating and cooling climates. Galvalume maintains its reflectance as it ages, and its low emissivity means it holds heat well in winter even though it reflects well in summer.

    Tile Roofing
    It's conventional wisdom that tile roofs are cooler than shingle roofs. To a small extent, that's true: S-tiles permit cooling airflow between the tile and the roof deck, and their thermal mass stores energy during the day and re-radiates it at night, instead of passing it all through to the attic.

    But the color of the tile matters. For instance, we painted some dark gray tiles bright white at midsummer in central Florida in 1996, and we measured an 18% drop in space-cooling energy.

    Shape appears to be far less important than color. In the seven-home side-by-side study for Florida Power & Light, one of the homes had flat white tile, and another had white S-tile. We didn't see much difference -- both roofs did about 20% better than the asphalt shingle roof. An S-shaped red tile roof in the same study was only 3% better than dark asphalt shingles.

    In general, light-colored metal roofs will outperform tile in a hot climate like Florida's. At night, they actually radiate attic heat upward into the night sky, cooling the attic to below the ambient air temperature. The thermal mass of tile will not let attic heat escape so readily.

    Radiant Barrier Systems
    When a house has a dark, sun-absorbing roof, radiant barriers in the attic can cut heat gain and save energy. But they don't necessarily work in every case, and they're not always the best solution.

    The basic radiant barrier is a layer of aluminum foil placed with its shiny side facing a clear air space. Placed under the rafters, aluminum's low emissivity prevents heat from radiating off the shiny surface onto the insulation below (Figure 4). If the surface gets dirty, it won't work as well; that's why radiant barriers placed shiny side down, so dust can't collect, work better than radiant reflective material placed facing up.

    FI-Foil Corp.
    Solec, Inc.
    Figure 4. Radiant barrier foil under the rafters stops heat from radiating into the attic, because the foil will not emit heat radiation even when it's hot (top and middle, before and after). Lo/Mit low-emissivity silicone coating spray-applied to the roof underside (bottom) is a cost-effective alternative method.

    There's now a range of material choices for attic radiant barriers, including radiant-barrier sheathing, spray-applied low-emissivity coatings, and a wide variety of foil products. Homes with complex attic geometry and poor access to the space are not great candidates for a foil application, but a radiant barrier sheathing is easy to apply to any new house, and a spray-applied low-e coating such as Lo/Mit from Solec, Inc. ( makes a practical retrofit.

    Energy savings. Radiant barriers are effective. Our research indicates that under-roof foil barriers reduce heat flow through the ceiling by 30% to 50% and can bring annual cooling electricity savings of 7% to 10% in the Southeast climate.

    Radiant barriers also have a strong effect on peak loads for the air conditioner. A nine-home retrofit study we conducted for Florida Power Corporation found that radiant barriers reduced air-conditioning power use by 9% and cut afternoon air-conditioning peak loads by 16%. In a six-ton system, that's a ton of cooling. Attic temperature peaks dropped by about 8°F. Perhaps most important, indoor temperatures fell by an average 2°F -- a boost for homeowner comfort.

    But that was in the South. In colder climates, radiant barriers may create a risk of wintertime condensation, because some foil products also act as vapor barriers. For cool-climate homes, it's wise to search out a product that has high permeability as well as low emissivity (manufacturers can supply data sheets with perm ratings, emissivity ratings, and other useful information).

    And be aware that if you have a reflective roof to begin with, a radiant barrier is overkill -- and may even be counterproductive. Since the underside of a reflective roof does not get hot, a radiant barrier under the roof adds little benefit. On the other hand, by reflecting heat inward, the radiant barrier will impede the ability of the attic to radiate excess heat to the night sky.

    Another word of caution: We installed our test radiant barriers in midsummer, so we could immediately measure the benefit. But the attics we worked in were dangerously hot -- one of our people actually had to stop and get medical attention. It's much safer to install attic radiant barriers in the cool season, or at least during the early morning before the attic is baking hot.

    Boosting Attic Ventilation
    If the attic is too hot, is more ventilation a good idea? Maybe, but maybe not. Increasing the roof's passive air vents can reduce the cooling load, but it is usually one of the least effective options. The incoming ventilation air is hottest just when you need the cooling.

    In retrofit work, we have seen increased ventilation bring a 5% reduction in building cooling loads. But in humid or coastal locations, it can also create problems: At night, the vents bring in moist outside air that may condense on duct systems.

    Since passive vents work inconsistently, some people recommend powered ventilation fans. But the electric power used to operate the fan usually outweighs the air-conditioning savings. And there's another drawback: Power attic ventilation can depressurize the house and cause gas water heaters to backdraft. It may also draw conditioned air out of the house into the attic, creating a further energy penalty.

    We've conducted tests of photovoltaic solar-powered attic fans in Florida. They run whenever the sun is shining, and we found savings of about 6% on electric bills. But at around $600 for the solar panels plus the fan, the savings don't really justify the cost in simple financial terms.

    Added Insulation
    Added insulation is another option for cutting heat gain through the roof. It certainly works: One of our studies for a Florida utility showed that boosting ceiling insulation from R-19 to R-30 cut space cooling by about 9% in summer.

    But your mileage may vary. Duct systems in many homes run through the hot attic and may be insulated to only R-4 or R-6. So the air conditioner is sending 55°F air into the duct in a space that can reach 130°F on a hot day. That's a temperature difference of 75°F, across just an R-6 insulated duct wall -- much greater than the 20°F difference you might see from indoors to outdoors across an R-11 or R-19 building wall. And duct surface area is much greater than you might think -- often as much as 25% of the house floor area. During the hottest hours, as much as 30% of the cooling system's capacity can be lost to heat gains in the duct system. Besides the wasted energy, this means it takes longer to cool down the house when the air conditioner kicks in.

    Unlike a reflective roof or attic radiant barrier, ceiling insulation does little to address duct system losses. So if your design relies on ceiling insulation to limit roof-related cooling loads, try to locate the duct system within the thermal envelope, below the insulated ceiling. Even running the ducts through the crawlspace, though they might be exposed to outdoor air temperatures, will add less to the load than running them through the solar-heated attic.

    Insulated Roof Deck With Sealed Attic
    Sealing the attic and insulating the roof deck is another way to get the duct system into a more friendly environment. Some code officials may not like this roof design, and researchers don't recommend it in colder climates, but it does save energy. It also creates semi-conditioned storage space in the attic, reduces interior moisture loads in hot climates, and avoids the risk of condensation on air handlers and ducts.

    In our seven-home side-by-side comparison, the house with a sealed and insulated attic used 9% less energy than the base case house, even though both had dark shingles. Some of us were expecting a greater savings, but several factors limit the benefit of this method.

    The big advantage is that the ductwork is inside the thermal envelope. However, while a ventilated attic can flush some heat out through the vents, an insulated roof deck fights its whole battle at the roof surface. Also, the air conditioner has to treat the additional air volume of the attic space.

    Beyond that, an insulated roof deck contributes more heat to the house than an insulated attic floor does. Heat transfer is proportional to the temperature difference, and also to the area of the surface. In a ventilated attic on a hot day, the top surface of the ceiling insulation may hit 130°F -- a 55°F difference with the 75°F interior. But the deck of an insulated roof in the direct sun may reach 170°F while the attic reaches 85°F, for a difference of 85°F across the insulation. That wider temperature gap drives faster heat gain. And that faster gain is multiplied by a greater area, since the roof area is anywhere from 5% to 40% greater than the ceiling area, depending on the pitch of the roof (not to mention the gable ends).

    So with an insulated roof deck and a sealed attic, it is very worthwhile to block that solar gain right off the bat: Use a lighter tile, white shingles, or a more reflective metal. In our study, the sealed system with dark shingles did about 9% better than a ventilated attic with dark shingles. With a reflective roof, the sealed attic would likely post savings of 25% or 30%. Even matched with white shingles (with a reflectance of 25%), we estimate that the insulated roof would have scored about a 13% savings compared to the dark shingles and vented attic. Also, it's worth noting that we carefully sealed the ductwork in all the test houses, to avoid confusing the results. If the ducts are leaky, the benefit of a sealed attic is much greater, because those leaks can't communicate with the outdoors.

    Options for Stopping Rooftop Heat Gain
    Field research at the Florida Solar Energy Center (FSEC) has found several effective ways to limit rooftop heat gain in sunny conditions. Using a highly reflective roofing material (top) is the simplest and most effective: It stops the sun's energy before any heat is absorbed, so that even the roof sheathing and framing stay cool. If the existing roof is dark colored or the customer prefers a darker roof, heat can still be blocked by adding a radiant barrier foil just below the roof deck (middle). Savings from this method are roughly comparable to the saving achieved with reflective roofing; however, some conductive heating of the attic space will still take place, and the roof deck and shingles will experience some increased heat stress. A third option is to increase the insulation between the attic and the living space below, and to run the hvac ductwork within the conditioned space rather than in the unconditioned attic. This method has a smaller effect on cooling loads than the reflective or radiant barrier roof systems but is effective at reducing heating loads as well as cooling loads, making it the most cost-effective option in mixed heating and cooling climates.


    Smart Choices
    Good roof details can save energy anywhere in the country. But climate and other building details do affect the choices. Here's how to approach the decision:

    Northern climate options. If you build in the North, reflective roofing materials or radiant barriers bring only modest savings. Adding insulation in the attic is a much more cost-effective upgrade. Insulation cuts both heating and cooling costs; and the heating savings in northern winters add up to much more money. (For the full benefit, it's important to run ductwork within the insulated envelope -- winter or summer, ducts in the attic will bypass the ceiling insulation and reduce its effectiveness.)

    Not that cooling doesn't matter up north, however. In summer, attics get hot everywhere. So even in the North, reflective roofing or radiant barriers may be worth installing simply to improve summer comfort and to reduce peak loads on the air conditioner. But if you want a reflective roof in the North, look for a material like Galvalume that is both reflective and low-e: This conserves attic heat during the winter as well as providing a summer cooling benefit.

    Southern choices. Down south, reflective roofs are a no-brainer -- they're money in your pocket. Air conditioning is the big energy cost, and reflective roofs can cut it by a third in the hottest months. Increasing the attic insulation can't hurt, but reflective roofs are more cost effective, particularly if the ductwork runs through the attic.

    If you're stuck with a dark roof, attic radiant barriers can achieve savings comparable to a reflective roof's performance. But if you use radiant barriers under an asphalt shingle roof, you're wise to also choose white shingles, just so the shingles themselves won't get quite so hot.

    Good ductwork location and reflective or radiant-barrier roof construction bring independent benefits, but they also complement each other. If you have a dark roof and a hot attic, bringing the ductwork below the insulated ceiling will help quite a lot. If the ducts are in the attic, switching from a dark roof to a reflective roof can help. But combining the two tactics -- applying reflective roofing and bringing the ducts inside -- provides the greatest total benefit. In a hot climate like Florida's, your summer cooling loads could drop by as much as 40%.

    By Danny Parker ,Danny Parker is a senior research scientist with the Florida Solar Energy Center. Article Supplier:

    Scotts Contracting is available for all your Remodeling Needs email to schedule a free green site evaluation
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    ENERGY STAR E-Update:Quadruple Energy Savings,DOE to Create $130M Research Center,Retailers Can Save When They Go Green,Study: White Roofs Can Cool Urban Temperatures,Tips for Foodservice Operators,more

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     from Scotty's mail box
    EPA Ranks U.S. Cities with the Most ENERGY STAR Labeled Buildings
    EPA maintains a list of all buildings that have earned EPA's ENERGY STAR and, for the second year, has created a list of the U.S. metropolitan areas with the largest number of ENERGY STAR labeled buildings. Continuing the impressive growth of the past several years, in 2009 nearly 3,900 commercial buildings earned the ENERGY STAR, representing annual savings of more than $900 million in utility bills and more than 4.7 million metric tons of carbon dioxide emissions. Los Angeles, Washington, D.C., San Francisco, Denver, Chicago, Houston, Lakeland, Dallas-Fort Worth, Atlanta, and New York head the list of cities. Details are available in the EPA Press Release. Houses of Worship will be added to this list in 2010 since these facilities can be rated using Portfolio Manager and can earn the ENERGY STAR. Learn moreabout the Houses of Worship rating. Link

    ENERGY STAR Leaders Quadruple Energy Savings in One Year

    In 2009, EPA's ENERGY STAR leaders prevented the equivalent of more than 220,000 metric tons of carbon dioxide and saved more than $48 million across their commercial building portfolios. These savings have quadrupled since 2008 and represent the single greatest year of savings since EPA recognized the first ENERGY STAR leaders in 2004. For details on the awards see the EPA Press Release. This year EPA released a new report profiling leading organizations for reducing greenhouse gas emissions through energy efficiency. The report: "Profiles in Leadership, 2010 ENERGY STAR Award Winners," highlights over 100 organizations across many sectors of the U.S. economy. The report offers insights into this diverse set of winners and their energy-efficient approaches and practices. For more information see the EPA Press Releaseor view the full report.

    DOE to Create $130M Research Center for Building Efficiency

    The Obama administration has announced that the U.S. Departments of Energy, Commerce and Labor and four other federal agencies are joining together to establish a nearly $130 million regional research center to develop and implement new technology for building efficiency. Buildings account for almost 40 percent of U.S. energy consumption and carbon emissions. The new center is part of the effort to reduce energy use and utility bills while stimulating the economy and creating jobs. Greener Buildings has the report. Link

    Retailers Can Save When They Go Green

    Retailers can save big bucks by thinking of green and energy-saving alternatives. From keeping the freezer door closed to examining tax incentives there are plenty of options to save money through green practices. See the article in Globe Streetwith more information.

    Study: White Roofs Can Cool Urban Temperatures

    White roofs can cool urban temperatures, according to Keith Oleson, a scientist at the National Center for Atmospheric Research. Such roofs are being used in cities across the country -- including Washington, D.C., and Seattle -- and have caught the attention of Energy Secretary Steven Chu. Review the entire article on MSNBC.

    Scott's Contracting, St Louis, Missouri: Installs Eco Friendly Roofing Choices for all Applications
    Contact Scotty for Pricing & Installation

    Tips for Foodservice Operators
    Restaurants & Institutions offers tips for food service operations and restaurants that want to adopt more environmentally sustainable measures. "There is a huge misconception," said Chris Moyer, manager of the National Restaurant Association's Conserve initiative. "A lot of people think, 'If I'm not doing it all, then I'm not doing anything.'" Start with small steps, experts advise, such as separating your trash and investing in green cleaning products. Then you can focus on larger commitments, such as replacing incandescent bulbs and getting LEED certification. See the full article in Restaurants & Institutions.

    ENERGY STAR Product of the Month:
    Commercial LED Lighting

    LED stands for light-emitting diode. LEDs are small light sources that become illuminated by the movement of electrons through semiconductor material. Qualified commercial products use at least 75% less energy and last 35 times longer than incandescent lighting. Plus, qualified LED lighting produces virtually no heat and provides optimal light color for any environment from parking lots to high-end show rooms. For more information, visit the ENERGY STAR product page which includes an overview, specifications, buying guidance and FAQs. LED technology is moving at a fast pace and you should check every few months for new types of LED lighting products.

    Build a Green St Louis!

    I'm trying to help my fellow stlouis neighbors from getting sick from nuclear radiation #BioRad Hazardous Waste Disposal eliminates toxic radiation in the soil. Scotty, writes: Sustainable Buildings are the future of the Construction Industry and our future Energy needs will be met from true Clean Energy Sources as well as creating Net Zero Energy Efficient Buildings for a sustainable future. Design Build Contractor for the St Louis Region-Specializing in Energy Conservation Design Build Projects and Solar PV Clean Energy Systems

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