Monday, April 30, 2012

Built-up roof restoration coating systems [+ video]



Since their inception more than 100 years ago, built-up roofs have earned a tried-and-true reputation as tough, durable and resistant to abuse and foot traffic. But what do you do when you are tired of chasing leaks or when your built-up roof finally does wear out completely?

UV rays oxidize the surface of an asphalt built-up roof, producing a chalk-like residue. As plasticizers leach out of the asphalt, the built-up roof becomes brittle and begins to blister and crack in a pattern that resembles alligator hide, allowing water to penetrate the roof system and cause leaks.

What are your options? You could tear-off your existing roof and install a new built-up system. On a 10,000 square foot commercial building, the tear-off alone could add 150 additional labor hours as well as the cost of renting 3 dumpsters to fill and haul to the local landfill - not to mention the cost of materials and installation of a new built-up roofing system.

But fortunately, complete tear-off and replacement is rarely necessary. A seamless built-up roof coating system is much less expensive, sustainable and a viable alternative in all climates. Roof coatings stop leaks and extend the life of your existing roof by 10 years or more without the cost of tearing-off the existing roof, disposing of it and installing a brand new built-up roof.

Another benefit is return on investment. Reflective coatings are cool roofing systems, which lower energy consumption. They also prevent premature roof deterioration by serving as a sacrificial layer to the elements, and reduce thermal-shock roof damage to the entire structure by moderating the excessive thermal expansion and contraction.

The installation process of a restoration coating system is fairly quick and easy, too:
  1. First, all known leaks are sealed, including flashings, cracks and splits.
  2. Next, Spray Polyurethane Foam, or "SPF" is applied to provide insulation, address ponding water areas, and to provide a surface conducive for coatings.
  3. Finally, the roof coating is applied to the entire roof surface to form a seamless protective membrane that produces a durable, weather-resistant and energy efficient surface and that can be walked on for normal maintenance.
So before you replace your worn out built-up roof, consider getting a quote from a professional roofing contractor who specializes in built-up roof restoration coatings for a more affordable, more energy efficient, more environmentally friendly, more sustainable, and faster-to-install alternative to re-roofing.


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Friday, April 27, 2012

Infrared-reflective architectural metal cool roofing

Infrared-reflective pigments are being incorporated into architectural metal roofing products to allow them to achieve higher reflectivity values, even in darker colors such as black and brown.

The improved reflectivity (for example, black changes from 0.07 with normal pigments to 0.32 with infrared-reflective pigments) can mean a much cooler surface temperature and greater energy savings for the building, allowing building owners and managers to select a sustainable roof without sacrificing aesthetic color choices.

To get 1 point for Sustainable Sites Credit 7.2: Heat Island Effect, the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) green building rating system specifies Energy Star requirements, adding a 0.9 emissivity standard.

For steep-sloped roofs, those with a rise-to-run ratio of 3:12 or greater, a 0.25 initial solar reflectance is required. In most cases, coated metal roofs can easily surpass the reflectivity requirement, and in some cases they can achieve 0.9 emissivity. More often they only achieve an emissivity of 0.85, thereby eliminating them from achieving the LEED point. For low-sloped roofs, those below 3:12, and flat roofs, the LEED reflectivity requirement is raised to 0.65, and the 0.9 emissivity standard is the same.

The Cool Metal Roofing Coalition, an organization comprised of metal industry trade associations, is providing commentary and data to USGBC requesting consideration for a reduction of the emissivity standard to around 0.7, contending that in addition to metal roofing’s energy efficiency when the reflective pigments are incorporated into a system’s design, metal’s long term ability to retain its reflective properties and a low life-cycle cost justify reducing the standard. The 0.9 standard “restricts a building owner’s ability to apply a suitable, long-term roof,” says Greg Crawford, executive director of the Coalition. The emissivity standard of 0.9 “is somewhat arbitrary,” says Andre Desjarlais, program manager for the Building Envelope research program at Oak Ridge National Laboratory, a supporting member of the Coalition. The 0.9 standard “is not defensible, but neither is eliminating emissivity altogether. We’re searching for middle ground.”


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Tuesday, April 24, 2012

Concordia University professor advocates cool roofing to fight climate change

Hashem Akbari, professor of civil and environmental engineering at Concordia University in Montreal, Quebec (Canada) believes a significant part of the of global-warming solution has to do with roofing. Something as simple as the color of roofs in a urban area can contribute significantly to combating global warming, saving homeowners and building owners energy costs in the process. Akbari says that installing a white, or "cool" roof would not absorb as much heat as a standard dark roof is a key element to fighting global warming.

"Cool roofs save you energy if your building is air-conditioned. If the building needs air conditioning, installing a cool roof may actually solve your problem and you may not need it," he said. "This all would be done at zero cost because you basically do that at the time you are changing your roof. At that time... you just select a white roof or light roof. If you do that then you also improve the ambient air quality within the city and you cool the globe."

Scientists sketched a vision of converting the world's cities into giant sunlight reflectors to help fight global warming. Gradually replacing traditional urban roofs and roads with white or lighter-coloured materials would yield a cooling benefit that, over 50 years, would be the equivalent of a reduction of between 25-150 billion tons of carbon dioxide. At the top end of the scale, this equals the emissions of all the world's cars over the same period, their study published in Britain's Institute of Physics' journal Environmental Research Letters stated.

Light-colored materials like those manufactured by Conklin Roofing Systems help reflect the sun's rays rather than absorb and convert them into heat (a phenomenon known as albedo).

Pavements and roofs make up more than 60% of urban surfaces. By trapping solar energy, they are largely to blame for heat islands, where cities or metropolitan areas become local hot spots. Urban heat islands consume massive energy in air conditioning and inflict significant health costs through smog.

Akbari - also founder and executive vice-chair of the Global Cool Cities Alliance - said in cooler places that require more heat in the winter, but also require air conditioning in the summer the net savings will still benefit the consumer. He said the savings a light roof would achieve in the summer months by keeping the home cool would more than offset the additional need for heat in the winter. "This is a measure that saves everybody throughout the world, uniformly, in terms of energy saving," noting that the idea is not a fix-all for climate issues. "It improves the ambient comfort and it cools the globe. There is absolutely no negative impact for this."

Mr. Akbari also states "There's not going to be a silver bullet or one single technology that solves the global warming problem. If there was, we would have already done it."


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Friday, April 20, 2012

How much money can you save from installing a white roof coating system?

The Environmental Protection Agency (EPA) has conducted several studies that demonstrate that in hot sunny conditions, a black roof surface is 70 degrees or more hotter than a white reflective roof surfaces. Across the country, this translates to approximately $750,000,000 every year in reduced energy consumption simply by replacing existing black roofs with Energy Star rated white reflective roof coatings like the ones manufactured by Conklin Roofing Systems.

Reflective roof coatings can be made from a variety of materials that comply with building code standards for cool roofing. Installers of coating systems can either roll-on or spray-on roof coatings over existing spray polyurethane foam (SPF), metal, concrete, weathered asphalt, composite, modified bitumen, EPDM, TPO, PVC, and built-up roofing systems.

How much a particular building owner or manager will save from installing a white reflective roof coating depends on climate, existing insulation, the roofing system being coated, utility rates, the particular materials being used, installation method by the contractor, and other factors. There are tools available to calculate your specific savings potential such as the Department of Energy Cool Roof Calculator and the Roof Savings Calculator.


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Wednesday, April 18, 2012

The benefits and controversy of white roofing

Much has been made in recent years about the benefits of installing white or “cool” roofs like those from Conklin. The idea is that light-colored materials reflect heat, while dark roofs (such as those made of asphalt and tar) absorb heat and drive up air-conditioning consumption in order to offset it. In other words, installing a roof that is white or “reflective” helps save energy and money.

Energy Secretary Steven Chu has pressed Americans to install cool roofs on their homes and business, even committing his own department to making all its new roofs white, but is the hype about cool roofs legitimate? Should you consider one for your home or commercial building?

The net energy savings generated by white roofs compared with dark roofs depends partly on where you’re located. White roofs seem like no-brainers in warm climates like Phoenix, Las Vegas and Miami, where they can keep air-conditioning bills in check year-round. States like California even now mandate white roofs on commercial buildings. But in cooler climates like Detroit or Toronto, the issue is less straightforward.

While white roofs may shave electric bills in hot summer months, some studies suggest they increase winter heating bills. The question is by just how much. Some scientists say white roofs can increase heating costs more than they save on A/C costs, although scientists at Lawrence Berkeley National Laboratory dispute this - saying the electricity savings of air-conditioning has found to outweigh any negatives, even in cool cities like Minneapolis.

If you do decide to install a white roof on your business or home, make sure you do some research about costs and options in your area and get at least a few bids from different professional roofing contractors who specialize in cool roofing. There are several different types of reflective roofing materials, and there is a right way and a wrong way to install them.

Also look into incentives available to you. Some states offer rebates for installing white roofs, as do some electric utilities. You can look up incentives online at DSIRE.


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Monday, April 16, 2012

Benefits of Spray Polyurethane Foam (SPF) roof systems [+ video]



Foam roofing systems provide many benefits to home and building owners, including waterproofing, insulation value, superior strength, light weight, durability, uplift wind resistance, and longevity.

Spray Polyurethane Foam, or "SPF", has been around for over 40 years. It is applied as a liquid using plural-component spray equipment and expands 30 times its original liquid volume to form a hard, closed-cell monolithic roof surface. Polyurethane foam dries within seconds after it is applied to the roof surface, resulting in a weather-tight roofing membrane that is fully adhered to the substrate.

Once the SPF has been applied to the proper thickness and finish specifications, a protective layer of elastomeric, acrylic, silicone, or polyurethane coating or granule is applied. This protective layer produces a durable, weather-resistant surface and that can be walked on for normal maintenance.

If a white roof coating is chosen, further energy efficiency and sustainability benefits will be realized over the life of the roof as well.

Spray polyurethane foam roofing systems have good adhesion to a variety of substrates, including metal, wood, concrete, modified bitumen, asphalt shingle, clay tile, and built-up, so in many cases this is a viable alternative to re-roofing.

With facilities budgets being more carefully managed in today's economy, there is a growing desire by roofing contractors to provide owners with durable, long-lasting yet affordable roofing systems that combine high energy performance with low maintenance costs.

Under suitable environmental conditions, a relatively small crew can install large jobs and tear-off is usually not required, which keeps costs and project durations low. Although SPF may be a good fit for your building, it does take an experienced, certified contractor to specify, install, or maintain these systems correctly.

How long do foam roofing systems last? Multiple studies conducted by the National Roofing Foundation found that SPF roofs have an effective service life of more than 30 years, assuming proper and regular inspections, cleaning and maintenance are performed. SPF roofing systems typically are re-coated every 10-15 years to maximize the life of the roof system.

SPF roofing systems vary widely in cost depending on the foam thickness required, the type and thickness of the coating or covering, the degree of substrate preparation, availability of contractors in a specific region, and other factors. As with other roofing systems there are both high-end and low-end material.

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Thursday, April 12, 2012

White roofs cool cities more than trees do

Cities are hot spots. Their paved surfaces and dark rooftops absorb energy from the sun, which creates localized areas of high temperatures. These hot roofs and blacktops collectively create a blanket of retained warmth in a city, raising temperatures an annual average of about 2-5 degrees Fahrenheit. This phenomenon (known as the urban heat island effect) can have huge impacts on energy use and even health in the warm months, almost like wearing a city-sized sweater on a hot day in July.

As cities become focused on reducing energy use and costs, this inherent increase in temperature is seen as an important target. Combating the urban heat island effect has become an official imperative in cities across the county and all over the world. There are various approaches to fighting the problem, but the primary methods are to plant more trees and make roofs reflect rather than absorb heat.

"Million Tree" campaigns have been launched in cities like New York and Los Angeles, and Phoenix recently approved a Tree and Shade Master Plan to increase the city’s tree canopy to cover 25% of the city over the next two decades. And while trees can help bring down temperatures, new research suggests that it might make more sense to invest in white roof coatings.

In a study recently published in the journal Building and Environment, researchers from Yale University show that the cooling effect of tree cover and other vegetated areas is far outpaced by the cooling achieved through reflective roofing. By analyzing satellite imagery of the city of Chicago from around 1995 and 2009, the researchers found that the parts of the city that had increased their reflectivity show greater reductions in temperature than areas that increased their vegetation.

"That might be contrary to the established view the field has," says Chris Mackey, lead author of the report who started the research as an undergrad studying architecture at Yale. That’s not to say planting trees is a bad method - it’s just not as good as making a rooftop more reflective.

These findings, co-produced by Mackey and a team of researchers at Yale’s Center for Earth Observation, add extra validation to efforts by Chicago, which in 2008 implemented an ordinance requiring most new roofs and roof renovations to be constructed using reflective materials. The program is implemented through the city’s energy conservation code, which passed in the early 2000's.

This study offers at least some data on how well that program is working. The city’s Department of Buildings doesn’t have any hard figures on how many reflective roofs have been built or installed, but Mackey says the satellite imagery he used shows parts of the city with huge swathes of white. One neighborhood had an estimated 80% conversion from black tar roofs to reflective surfaces, and Mackey says the observed temperatures in that area dropped at least 38 degrees. Another collection of warehouses with reflective roofs saw drops of at least 41 degrees.

What conspicuously did not show any significant signs of cooling are the city’s famous green roofs. Because the vegetation of these gardens is at such a low density, it hardly registered in Mackey’s analysis. Not even the well-known City Hall green roof exhibited cooling power.

"The green roof is barely doing anything in comparison to the tree, and the tree is barely doing anything in comparison to painting a warehouse roof white," Mackey says. "I don’t want to discredit green roofs as not potentially a good thing at all. But it would take a lot of money and effort to get a high enough density of vegetation to start cooling things down."

What takes less money and effort is the reflective roof approach. The EPA estimates that "cool roof" coatings and membranes like those from Conklin cost about 5-20 cents more per square foot when compared to traditional roofing methods. A 10,000 square foot roof might cost about $4,500 to coat with reflective roofing, while a similarly sized green roof could cost upwards of $150,000.

"If you were trying to develop a heat island strategy, reflective roofs would be the easiest and most effective," Mackey says.

Green roofs and planting shouldn’t be ignored, but Mackey suggests that the reflective roof approach would be a good way to make dramatic changes quickly. "Once you reach that capacity, then you could start to focus on vegetation increases," he says.


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Tuesday, April 10, 2012

The long history (and future) of white roofs

Unlike high-technology solutions to reduce energy use like light-emitting diodes (LED's) in lamp fixtures, white roofs have a long and humble history. Houses in hot climates around the world have been whitewashed literally for centuries now.

From a U.S. perspective, before the advent of central air-conditioning in the mid-20th-century, white and cream-colored houses with reflective tin roofs were the norm in places like South Florida. Then central air-conditioning arrived, along with dark roofs whose basic ingredients were often asphalt, tar and bitumen, or asphalt-based shingles. These materials absorb as much as 90% of the sun’s heat energy — often useful in New England, but less so in places like Texas. By contrast, a white roof can absorb as little as 10-15%.

"Relative newcomers to the West and South brought a lot of habits and products from the Northeast,” said Joe Reilly, the president of American Rooftile Coatings, a supplier. “What you see happening now is common sense.”

Around the country, roof makers are racing to develop products like those from Conklin in the hope of profiting as the movement spreads from the flat roofs of the country’s malls to the sloped roofs of its suburbs.

Years of detailed work by scientists at the Lawrence Berkeley Laboratory have provided the roof makers with a rainbow of colors, showing the amount of light that each hue reflects and the amount of heat it re-emits. White is not always a buyer’s first choice of color, so manufacturers like Conklin and others have used federal color charts to create “cool” but traditional colors, like cream, sienna and gray, that yield savings (though less than what purely white roofs do).

In an experiment, the National Laboratory in Oak Ridge, Tennessee, had two kinds of terra-cotta-colored cement tiles installed on four new homes at the Fort Irwin Army base in California. One kind was covered with a special paint and reflected 45% of the sun’s rays — nearly twice as much as the other kind. The two homes with roofs of highly reflective paint used 35% less electricity last summer than the two with less reflective paint.

Hashem Akbari of Lawrence Berkeley Laboratory says he is unsure how long it will take cool roofs to truly catch on. But he points out that most roofs, whether tile or asphalt-shingle, have a life span of 20-25 years. If the roughly 5% of all roofs that are replaced each year were given cool colors, he said, the country’s transformation would be complete in just two decades.


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Friday, April 6, 2012

White roofs catch on as energy cost-cutters

Returning to their ranch-style house in Sacramento after a long summer workday, Jon and Kim Waldrep were routinely met by a wall of heat. “We’d come home in the summer, and the house would be 115 degrees, stifling,” said Mr. Waldrep, a regional manager for a national company.

He or his wife would race to the thermostat and turn on the air-conditioning as their four small children, just picked up from day care, awaited relief. But all that changed last month. “Now we come home on days when it’s over 100 degrees outside, and the house is at 80 degrees,” Mr. Waldrep said. Their solution was a new roof - a shiny plasticized white covering that experts say is not only an energy saver, but also a way to help cool the planet.

Relying on the centuries-old principle that white objects absorb less heat than dark ones, homeowners like the Waldreps are in the vanguard of a movement embracing “cool roofs” as one of the most affordable weapons against climate change. Studies show that white roofs reduce air-conditioning costs by 20% or more in hot, sunny weather. Lower energy consumption also means fewer of the carbon dioxide emissions that contribute to global warming. What is more, a white roof can cost as little as 15 percent more than its dark counterpart, depending on the materials used, while slashing electricity bills.

Art Rosenfeld, a member of the California Energy Commission who has been campaigning for cool roofs since the 1980s, argues that turning all of the world’s roofs “light” over the next 20 years could save the equivalent of 24 billion metric tons in carbon dioxide emissions. “That is what the whole world emitted last year,” Mr. Rosenfeld said. “So, in a sense, it’s like turning off the world for a year.”

This month the Waldreps’ three-bedroom house is consuming 10% less electricity than it did a year ago (the savings would be greater if the family ran its central air during the workday).

From Dubai to New Delhi to Osaka, Japan, reflective roofs have been embraced by local officials seeking to rein in energy costs. In the United States, they have been standard equipment for a decade at new Wal-Mart stores. More than 75% of the chain’s 4,268 outlets in the United States have them.

California, Florida and Georgia have adopted building codes that encourage white roof installations for commercial buildings. Drawing on federal stimulus dollars earmarked for energy-efficiency projects, state energy offices and local utilities often offer financing for cool roofs. The roofs can qualify for tax credits if the roofing materials pass muster with the Environmental Protection Agency’s Energy Star program. Still, the ardor of the cool-roof advocates has prompted a bit of a backlash.

For most types of construction, light roofs yield significant net benefits as far north as New York or Chicago. Although those cities have cold winters, they are heat islands in the summer with hundreds of thousands of square feet of roof surface absorbing energy.

The physics behind cool roofs is simple. Solar energy delivers both light and heat, and the heat from sunlight is readily absorbed by dark colors (an asphalt roof in New York can rise to 180 degrees on a hot summer day). Lighter colors, however, reflect back a sizable fraction of the radiation, helping to keep a building — and, more broadly, the city and Earth — cooler. They also re-emit some of the heat they absorb.


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Wednesday, April 4, 2012

Elmer's Roofing Service talks roof coatings on BBB Straight Talk



Elmer Dowling of Elmer's Roofing Service in Hortonville, Wisconsin discusses white reflective elastomeric roof coatings on BBB Straight Talk. Elmer can be reached at (920) 841-2314 or via email at elmer.1@att.net. You can find Elmer's Roofing on Facebook at https://www.facebook.com/ElmersRoofing.

The discussion included the following topics:
  • About Elmer's Roofing
  • What are roof coatings?
  • How long have roof coatings been around, and why were they developed?
  • What kind of a roofs are coatings best suited for?
  • Can you coat asphalt shingles?
  • How long do roof coatings last?
  • Commercial and residential roofing
  • No tear-off required with roof coatings
  • How do you install coatings around roof penetrations?
  • Advantages and benefits of roof coatings
  • Roof coatings are generally white
  • Are there advantages of a black roof during winter?
  • Can you install roof coatings on new construction?
  • You can install coatings on flat and sloped roofs
  • How long does it take to install roof coatings?
  • How big of a crew do you need to install roof coatings?
  • Homeowner considerations and questions to ask a roofing contractor
  • How and why did Elmer's Roofing begin focusing on roof coatings?
  • Hiring a trained, certified installer vs. DIY
  • Free estimates and roof evaluations
  • Elmer's Roofing service area
  • The future of embracing and mandating cool roofs

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Monday, April 2, 2012

White roof tops stay far cooler in the summer, new study confirms

On the hottest day of 2011 in New York City, a white roof was measured at 42F cooler than a black roof it was compared to, according to a study including NASA scientists that details the first scientific results from the city's unprecedented effort to brighten rooftops and reduce its "urban heat island" effect.
The dark, sunlight-absorbing surfaces of some New York City roofs reached 170F on July 22, 2011, a day that set a city record for electricity usage during the peak of a heat wave.

But in the largest discrepancy of that day, a white roofing material was measured at about 42 degrees cooler. The white roof being tested was a low-cost covering promoted as part of Mayor Michael Bloomberg's effort to reduce the city's greenhouse gas emissions 30% by 2030.

On average through the summer of 2011, the pilot white roof surface reduced peak rooftop temperature compared to a typical black roof by 43F according to the study, which was the first long-term effort in New York to test how specific white roof materials held up and performed over several years.

Widespread installation of white roofs, like New York City is attempting through the NYC CoolRoofs program, could reduce city temperatures while cutting down on energy usage and resulting greenhouse gas emissions, said Stuart Gaffin, a research scientist at Columbia University, and lead author on a paper detailing the roof study. The paper published online March 7, 2012, in Environmental Research Letters.

The urban landscape of asphalt, metal, and dark buildings absorbs more energy from sunlight than forests, fields or snow- and ice-covered landscapes, which reflect more light. The absorption leads to what scientists call an "urban heat island," where a city experiences markedly warmer temperatures than surrounding regions. New York City's urban heat island has a more pronounced effect at night, typically raising nighttime temperatures between 5F and 7F relative to what they would be without the effect, according to Gaffin's previous research.

The problem leads to everything from spikes in electricity usage and greenhouse gas emissions to poorer air quality and increased risk of death during heat waves. In recent years, city planners worldwide have discussed cutting into this effect by converting dark roofs to either "living" roofs covered in plants or to white roofs, the far less expensive option.

"Cities have been progressively darkening the landscape for hundreds of years. This is the first effort in New York to reverse that. It's an ambitious effort with real potential to lower city temperatures and energy bills," said Gaffin. "City roofs are traditionally black because asphalt and tar are waterproof, tough, ductile and were easiest to apply to complex rooftop geometries. But from a climate and urban heat island standpoint, it makes a lot of sense to install bright, white roofs. That's why we say, 'Bright is the new black.'"

With climate change, the urban heat island problem will likely intensify in coming decades, said Cynthia Rosenzweig, a scientist at NASA's Goddard Institute for Space Studies in New York City and a co-author on the paper.

"Right now, we average about 14 days each summer above 90 degrees in New York. In a couple decades, we could be experiencing 30 days or more," Rosenzweig said.

The study found similar temperature reduction when all the surfaces were first installed, but that the professionally installed membranes maintained their reflectivity better over multiple years.

The fraction of incoming solar radiation reflected skyward determines what is called a surface's albedo. The citywide program is in effect an "albedo enhancement" program. In addition to measuring rooftop surface temperature, the study also looked at how the reflectivity and emissivity of the white surfaces held up over time. Reflectivity measures how much light a surface immediately reflects skyward. Emissivity measures how much infrared radiation a surface emits after absorbing solar radiation.

Both the reflectivity and emissivity of the professionally installed white membrane coverings held up remarkably well after even four years in use. These surfaces continued to meet Energy Star standards, set by the EPA's Energy Star Reflective Roof program.

The effectiveness of the white coating was about cut in half after two years, ultimately falling below the Energy Star standard. However, Gaffin said, the low-cost surface improved albedo markedly over typical black, asphalt roofs.

NASA studies the urban heat island effect to better understand and model how urban surfaces and expanding urbanization might impact regional and global climate, said Marc Imhoff, a biospheric scientist at NASA Goddard Space Flight Center, Greenbelt, MD.

"We're trying to build a capability where we can expand our knowledge with data on more locations, and ultimately develop computer models that would allow us to predict urban heat islands and urban temperatures on a town level," Imhoff said. "Eventually, we could incorporate our findings into large-scale, global climate models."


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