White Roofs Cool Cities More Than Trees
Source: http://www.theatlanticcities.com/technology/2011/11/white-roofs-cool-cities-more-than-trees/533/
Cities are hot spots. Their paved surfaces and dark rooftops absorb energy from the sun, which creates localized areas of high temperatures. Expanded out from the building scale to the city scale, these hot roofs and blacktops collectively create a blanket of retained warmth in a city, raising temperatures an annual average of about 2 to 5 degrees Fahrenheit. It’s a phenomenon known as the urban heat island effect, and it can have huge impacts on energy use and even health in the warm months. It’s 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, if largely amorphous, target. Combating the urban heat island effect has become, in a catch-phrasey sort of way, 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 hot hot Phoenix recently approved a Tree and Shade Master Plan [pdf] to increase the city’s tree canopy to cover 25 percent of the city over the next two decades. And while trees can help bring down temperatures (in addition to a variety of other beneficial impacts), new research suggests that it might make more sense to invest in white paint than white ash.
In a study just published online in the journal Building and Environment, researchers out of 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 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.
“Out of all the vegetated cooling techniques, probably planting trees or building really huge parks would be the best approach,” Mackey says. “But rarely, if ever, are we installing enough vegetation in one major effort to produce this much cooling.”
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 2000s. However, energy conservation isn’t really an issue here. The white roofs help keep energy use down in the summer, but have a negative impact in winter, which probably amounts to only a small net savings of energy, according to Javier Ceballos, a mechanical engineer in the city’s Department of the Environment.
Temperature cooling is the real goal of the ordinance. But Ceballos notes that nailing down the impact of the ordinance isn’t as clear to see as any resulting changes in energy use. “That environmental benefit is a lot more difficult to quantify,” he says.
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 percent conversion from black tar roofs to reflective surfaces, and Mackey says the observed temperatures in that area dropped at least 3.5 degrees Celsius. Another collection of warehouses with reflective roofs saw drops of at least 5 degrees Celsius.
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 cost about 5 to 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.
But green roofs and planting shouldn’t be ignored. 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.
A city full of white roofs would be cool, but a city full of trees would be cool in a much different way.
Like this:
Case Study: Wells Fargo Florida Branch Roof Protected by APV eCoolRoof® to Conserve Energy
(Akron, Ohio) – Pensacola, Florida, can get pretty hot in the summertime, with several days where the temperature clears 100 degrees. When this happens, the air conditioner in a building often runs continuously in an effort to keep inside temperatures down – and the effort isn’t always successful.
With this challenge in mind, an official with Wells Fargo® made the decision in January 2011 to redo the roof of the Northview Branch building in an effort to conserve energy and preserve the life of the roof. APV eCoolRoof® from APV Engineered Coatings®, a new cool roof coating system comprised of a Kynar Aquatec® resin-based topcoat and an elastomeric acrylic basecoat, was applied to the roof in April 2011. Working together, these two products can provide as much as 63 percent increase in life cycle energy savings for a structure.
Patrick Murrell, owner of Structure Cleaning and Coating and the nation’s first Pro-X Certified Contractor™ for APV eCoolRoof, was instrumental in the choice by Wells Fargo of the APV eCoolRoof coating system. A strong relationship with Wachovia led to the relationship with Wells Fargo as the company goes through the rebranding process of its bank branches. While this is Murrell’s first bank branch job using APV eCoolRoof, he suspects it won’t be his last.
“We expect the use of APV eCoolRoof to lower the utility bills of the branch quite a bit,” said Murrell. “Before application of the APV eCoolRoof coating system the roof temperature was around 140 degrees, while the underside of the roof inside the bank was 90 degrees – and this was when the outside air temperature was only 78 degrees. APV eCoolRoof is a quality product ideal for light commercial applications like this; we look forward to hearing about cooler days ahead inside the bank.”
Application of APV eCoolRoof is well-timed as Gulf Power Company launched their Commercial/Industrial EarthCents Programs on June 1, 2011. Offering commercial customer rebates, applicable upgrades include the installation of a reflective roof.
APV eCoolRoof was applied in mid-April, and folks at Wells Fargo plan to keep an eye on the project, noting before and after statistics, to determine whether to expand the product usage to additional bank branches. Initial statistics indicate that, since the application of the APV eCoolRoof product, the roof temperature of the building has been fluctuating between the same as the ambient air temperature to a maximum of three degrees above the ambient air temperature. This indicates a 60-62 degree decrease in roof temperature.
The installation process for the APV eCoolRoof coating system was quick: one day to clean and prep the roof of the building, one day to apply the basecoat and one day to apply the topcoat. The rolled asphalt roof of the branch covers about 6,400 square feet. Reflectivity (TSR) data of the uncovered roof (prior to APV eCoolRoof installation):
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Uncleaned Granulated Asphalt Rolled Roof |
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Total Solar Reflectance (TSR) |
|||
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0.147 |
0.138 |
0.146 |
0.175 |
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0.15 |
0.155 |
0.161 |
0.158 |
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0.136 |
0.158 |
0.17 |
0.17 |
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AVERAGE TSR: 0.155 or 15.50 percent |
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Following installation, the reflectivity (TSR) data of the roof coated with APV eCoolRoof:
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Granulated Asphalt Rolled Roof with APV eCoolRoof |
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Total Solar Reflectance (TSR) |
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0.878 |
0.888 |
0.877 |
0.881 |
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0.886 |
0.875 |
0.874 |
0.876 |
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AVERAGE TSR: 0.88 or 87.9375 percent |
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“APV eCoolRoof Topcoat has been engineered to significantly increase the emissivity and total solar reflectance properties of a roof’s surface and sustain it for a minimum of 10 years”, according to Thomas Venarge, president of APV Engineered Coatings. “This field-applied topcoat product is designed to be applied over APV eCoolRoof basecoat to produce the ultimate high performance barrier to the sun’s rays. Our research shows that this product extends the life of a roof by twice as long as a traditional roof coating.”
The eco-friendly APV eCoolRoof has a low VOC content and resists ultraviolet (UV) ray degradation, chalking, water pickup, dirt pickup, staining, chemicals and corrosion, algae and fungal growth along with abrasion. Made in Ohio, the product increases the comfort level of the interior of a structure by providing lower indoor temperatures, which reduces the amount of energy used from cooling systems.
The APV eCoolRoof coating system meets or exceeds initial Cool Roof Rating Council (CRRC) requirements to reflect sunlight and heat away from a structure. The products are currently participating in a three-year certification program of age testing, after which they will qualify for ENERGY STAR® and CRRC ratings. Initial TRS readings taken by an independent test laboratory accredited by the CRRC, indicated APV eCoolRoof had an average TSR of 92.62 percent, currently the third-highest of all products rated by the CRRC.
Comprehensive APV eCoolRoof System
The single coat applications of both the basecoat and topcoat for APV eCoolRoof are field-applied and air dried, requiring no baking. Additional benefits include the white color retention of the glossy coating over years of service, reduction in maintenance costs and the ability to extend the life of a current roof.
The APV eCoolRoof Basecoat is field applied first to fill in pinholes or small cracks in an existing roof, help smooth the roof surface, and serve as a bonding layer for the topcoat. The topcoat is then applied and serves as long-term protection to sustain the reflectivity of the sun’s rays for a minimum of 10 years. The highly-durable topcoat resists chemicals, corrosion, dirt and algae/fungus. Used together, the two products increase the longevity and efficiency of a roof.
“The fluoropolymer technology in APV eCoolRoof provides a long and sustained lifespan for a roof,” says Venarge. “This product increases the surface’s reflectivity and emissivity ability and successfully sustains it for a minimum of 10 years. In comparison, over a 20 year period, the reduction of CO2 emissions of an APV eCoolRoof versus that of an elastomeric acrylic on an area the size of an average city block is equivalaent to taking 51 cars off the street.”[1]
Dependable Commercial Product
Available nationwide directly from APV Engineered Coatings for use on commercial projects such as high rise buildings, refrigerated warehouses, domed facilities, factories and stadiums, APV eCoolRoof is warranted for 10 years for reflectivity. The product may be applied over a multitude of surfaces, PVC, asphalt, rubber (including EPDM),
metal, SBS & APP modified bitumen, single-ply, and polyurethane foam systems.
The Kynar Aquatec resin used in APV eCoolRoof is a tough, engineered thermoplastic offering a unique balance of properties to withstand harsh thermal, chemical and UV environmental conditions. Manufactured by Arkema Inc., the resin provides APV eCoolRoof the ability to resist abrasions, dirt and the growth of mold and mildew.
For additional information on Structure Cleaning and Coating for projects nationwide, call 850-564-7420 or visit www.structurecoating.com.
Founded in Akron, Ohio in 1878, APV Engineered Coatings manufactures innovative, custom engineered products that are sold worldwide to a wide variety of industries. For more information on products and services, visit www.apvcoatings.com, www.ecoolroof.com, or call 800-772-3452.
[1]In reference to the “Cool White Roofing Savings Calculator App for iPhone” developed by Arkema Inc., this is derived from a study published by Lawrence Berkeley National Laboratory on energy savings and greenhouse gas reduction.
Related articles
- Bill Clinton Says ‘Paint Your Roofs White’ (politics.slashdot.org)
- Roof Color and Its Effect on the Environment (brighthub.com)
Image via Wikipedia
AKRON, OHIO – APV Engineered Coatings® announced recently that their cool roof coating system, APV eCoolRoof®, was granted registered trademark status by the U.S. Patent and Trademark Office. APV eCoolRoof is comprised of a Kynar Aquatec® resin-based topcoat and an elastomeric acrylic basecoat, which meets the high energy savings demands of property owners through its high, sustaining reflectivity values.
Along with high reflectivity, the eco-friendly APV eCoolRoof has a low VOC content and resists ultraviolet (UV) degradation, chalking, water pickup, dirt pickup, staining, chemicals and corrosion, algae and fungal growth along with abrasion. Made in Ohio, the product increases the comfort level of the interior of a structure by providing lower indoor temperatures, which reduces the amount of energy used from cooling systems.
The Kynar Aquatec resin used in APV eCoolRoof is a tough, engineered thermoplastic offering a unique balance of properties to withstand harsh thermal, chemical and UV environmental conditions. Manufactured by Arkema Inc., the resin provides APV eCoolRoof the ability to sustain the product’s reflective properties and resist against erosion, abrasions, dirt and the growth of mold and mildew.
Founded in Akron, Ohio in 1878, APV Engineered Coatings manufactures innovative, custom engineered products that are sold worldwide to a wide variety of industries. For more information on products and services, visit www.apvcoatings.com, www.ecoolroof.com, or call 800-772-3452.
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APV eCoolRoof is sold under a trademark license from ARKEMA INC. which is the owner of the KYNAR and KYNAR AQUATEC Trademarks.
APV eCoolRoof is a trademark belonging to APV Engineered Coatings.
Related articles
- The White Roof Project (kakarikistreet.wordpress.com)
Source: EnergyWorks On Tuesday June 28, 2011, 3:56 pm EDT
AKRON, June 28, 2011 /PRNewswire/ — Worried about the high cost of keeping cool this summer? For a limited time, EnergyWorks, a new program funded by the U.S. Department of Energy, is offering deeply discounted home energy assessments to homeowners to improve the energy efficiency of their homes in Bucks, Chester, Delaware, Montgomery, and Philadelphia counties.
EnergyWorks combines all available rebates, tax credits, and low-interest loans with the expertise of certified building analysts and qualified contractors to make home energy efficiency upgrades more affordable and easier than ever. An EnergyWorks energy assessment identifies all the ways homeowners can reduce energy bills while increasing market value, safety and comfort. EnergyWorks homeowners typically save up to 20% or more on energy bills year round.
“Home energy improvements like white roof coatings, upgrading to an efficient air conditioner, air sealing and insulation are all extremely cost-effective cooling changes that will improve your bottom line as well as your health,” said Joe DiBiase, owner of DiBiase Heating & Cooling, a Downingtown-based EnergyWorks contractor. “In addition, EnergyWorks building analysts check for water in basements, poor drainage, mold, roof leaks and carbon monoxide leaks to make homes a safer place for regional residents.”
The Farmers Almanac predicts a turbulent summer for the region, plus above-normal temperatures in July and August. DiBiase offers useful tips to help homeowners cope. ”An automatic setback thermostat, air sealing, and insulation are three of the most cost-effective ways to slice cooling bills and help save money all year round,” DiBiase said. “All of these improvements and many more qualify for EnergyWorks financing. Many also qualify for tax credits and rebates.”
Normally priced at $400, the home energy assessments are presently available for $150 plus an extra $50 rebate. In addition, with an EnergyWorks loan, homeowners can borrow up to $15,000 for less than 1% interest. Loans are payable over 10 years with payments as low as $9 per month on a $1,000 loan.
Chester County resident Rebecca Puchay took advantage of an EnergyWorks loan and was shocked at the difference it made in her utility bill. “I received my utility bill a few days ago and it was almost 40% less than last month,” Puchay said. “Thanks to EnergyWorks for making this happen.”
EnergyWorks provides homeowners with a safe, comfortable and healthy indoor environment with significant savings through hassle-free home energy improvements. The special pricing offer expires September 5, 2011. For more information on EnergyWorks visit http://www.energyworksnow.com or call 215-609-1052.
EnergyWorks is a program of the Metropolitan Caucus, a coalition of County Council Members and Commissioners from Bucks, Chester, Delaware, and Montgomery Counties and the Mayor of Philadelphia. EnergyWorks is supported by a grant from the U.S. Department of Energy’s Better Buildings Program.
EnergyWorks relies on the support of critical operating partners to provide services and make loans. These include the Keystone HELP program and AFC First Financial, the Energy Coordinating Agency, The Reinvestment Fund, and the Philadelphia Industrial Development Corporation.
Like this:
The Obama administration’s “Better Buildings Initiative,” a sweeping energy-efficiency retrofit plan, would generate significant employment in the hard-hit construction sector and have a positive “ripple effect” on other segments of the economy, a coalition of groups said Tuesday.
The U.S. Green Building Council, The Real Estate Roundtable and the Natural Resources Defense Council conducted a news teleconference to review an analysis suggesting that the initiative would generate more than 114,000 new jobs, many of them in the construction industry.
The Better Buildings Initiative is a White House plan to make existing commercial and multifamily buildings more energy efficient. The initiative, announced by President Obama in February, combines financial and other incentives to improve energy efficiency in the nation’s commercial and multifamily building stock.
The biggest job driver in the Better Buildings Initiative, which accounts for more than 77,000 of the new jobs, is a redesigned tax deduction for energy efficiency upgrades of buildings, the three organizations said in an announcement on the joint analysis. The analysis also shows how the initiative would have a “rippling” effect throughout the economy to generate more manufacturing, production and service jobs—and demonstrating how public funds can leverage significant private investments to expand the benefits to the economy.
The analysis suggests that job creation would occur in many industries, including businesses that produce building-envelope components and materials such as windows. doors, insulation, roofing, and paint and coatings.
The NRDC, Real Estate Roundtable and USGBC retained the Political Economy Research Institute (PERI) of the University of Massachusetts at Amherst to conduct the analysis, which can be viewed here.
The Better Buildings Initiative is comprised of several provisions, including the following.
- Changes to the tax incentive for energy-efficient commercial facilities—section 179D—to encourage improvements in existing buildings that reduce energy usage.
- Increased access to financing for retrofit projects via loan guarantees from the Department of Energy and Small Business Administration financing opportunities.
- A “Race to Green” competitive grant program for local and state governments that streamline regulations and attract private investment for retrofit projects.
- A challenge program for the leaders of private companies and academic institutions to reduce the energy consumption of their facilities with the help of multiple federal agencies and the Clinton Global Initiative.
- A workforce training program for the building sector based on the successful manufacturing extension partnership program.
A conclusion to the analysis says the administration and Congress “should work expediently to implement these policies and jumpstart the new retrofit economy in the country’s largest buildings.”
Key Objective: Revision of Tax Incentive
for Energy-Efficient Commercial Buildings
The organizations said reform of the existing tax deduction for energy-efficient commercial facilities represents “the largest opportunity for creation of new jobs.” The policy—the Energy Efficient Commercial Building Tax Deduction (Section 179D), signed into law as part of the Energy Policy Act of 2005—was primarily designed for encouraging energy-efficient new construction.
The organizations are recommending changes to the tax deduction to encourage retrofits. The recommendations include the following:
- Measure energy savings compared to the existing building baseline. Rather than requiring existing buildings to meet and exceed the requirements of the energy code for new construction, as is the case currently in 179D, measure improvements in how much energy consumption was reduced compared to where the building started.
- Link the amount of the incentive to energy savings achieved. Greater energy savings and deeper retrofits warrant larger incentives to reward innovation and to reflect the larger investments and greater environmental benefit. Energy savings in excess of 50% are possible, and will be encouraged by this approach.
- Tie a portion of the tax incentive to implementation of efficiency measures and a portion to demonstrated energy savings. There are good reasons to reward a building owner for implementing energy savings measures, and even better reasons to reward energy savings actually realized on the energy meter.
This proposal uniquely does both and maximizes accountability by allowing the building owner to claim 60% of the incentive at the time the energy-efficiency measures are put into service, and the remaining 40% of the incentive after two years of demonstrating the expected savings have occurred. This proposal enjoys significant support throughout the building industry, the organizations said.
More information on the PERI analysis and its figures on jobs creation from the White House’s Better Buildings Initiative is available at Better Buildings New Jobs.
APV eCoolRoof Application Video
Check out our latest video!
Two new solar energy incentives will make it easier for Gulf Power customers to harness the power of the sun.
The company is offering rebates to customers who install a qualifying solar thermal water heating system or a solar photovoltaic system that makes electricity.
“These EarthCents programs take advantage of renewable sources of energy like the sun,” said Jeff Rogers, Gulf Power spokesperson. “And the cash incentives can make the purchase and installation more affordable.”
Customers can apply for the incentives beginning May 31 at 8 a.m. CST at gulfpower.com.
A Solar Water Heating system uses the sun’s energy to heat water which helps lower electricity costs and conserve other energy sources. Gulf Power’s EarthCents program provides a $1,000 incentive for the installation of a qualifying solar thermal water heating system.
A Solar Photovoltaic (PV) system converts sunlight into electricity through solar panels to provide electricity for homes or businesses. Gulf Power is offering an incentive of $2 per watt up to a maximum of $10,000 per installation of a qualified system.
The program incentives are limited and must be reserved through an online application before installation of qualifying solar systems. Additional federal tax credits may also be available.
EarthCents programs feature something for every customer, from quick fixes to entire energy makeovers. Every customer can complete a free Energy-Check Up online or have an energy expert do an on-site analysis that will help identify ways to save money and energy.
For more details and to sign up for any of these programs, visit www.gulfpower.com or call 1-877-655-4001.
Gulf Power Company is an investor-owned electric utility with all of its common stock owned by Atlanta-based Southern Company. Gulf Power serves more than 430,000 customers in 10 counties throughout Northwest Florida. The company’s mission is to safely deliver affordable, reliable and environmentally responsible energy to very satisfied customers in strong communities. Visit our website at www.gulfpower.com.
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