- By James Kehrer
- July 1st, 2000
It’s becoming an increasingly familiar sight: a bright, scorching sun; a high heat index; a hot building in which students attend classes, and college and university personnel work; and air-conditioners taxed beyond normal capacities. To top it off, there is a demand to control energy costs.
Factor in a global warming situation, where the average daily temperature in many parts of the country has been steadily rising through recent years, and you have all the elements of a real-world concern for today’s educational administrators.
A Case in Point
When Georgia Tech in Atlanta wanted to reroof several buildings, they wanted roofs that would be long-lasting, leak-proof, virtually maintenance-free, energy-efficient and protected by a strong roofing manufacturer’s warranty. This is a tall order for any product.
Roofing contractors Wormley Brothers Roofing of Suwanee, Ga., and Interstate Consolidated Roofing of Douglasville, Ga., offered Georgia Tech administrators a smart solution. They installed a highly reflective, white roofing system on more than 10 roofs campuswide and are working on additional on-campus buildings. “We’ve had good success with a white roofing system; it has performed really well,” says James Hummel, Georgia Tech’s construction project manager.
Studies performed by Duro-Last, using the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE), the National Roofing Contractors Association (NRCA) and Georgia Power guidelines, back this system’s abilities on Georgia Tech’s build-ings; they show a potential 10-year reduction in cooling energy costs of 38 percent.
Georgia Tech is just one of many examples of how a college or university can save potentially more than 30 percent on cooling costs and help to reverse a dangerous environmental problem. This “win-win” situation has created an unexpected alliance among environmental organizations, research institutions and manufacturers of highly reflective roofing membranes. A common interest among these groups is reducing the energy associated with the cooling of buildings throughout the United States (especially in the Sunbelt).
Fighting Heat, Saving Energy
For the past several years, the United States Department of Energy and the Lawrence Berkley National Lab have been reporting on ways to reduce the “Urban Heat Island Effect.” This effect is caused when solar radiation is absorbed by dark, unreflective roofs as well as other building materials that then heat the building and the surrounding air. Gather several of these super-heated buildings together and an Urban Heat Island, or dome of elevated temperature, is created. Although few dispute the importance of these findings as a national environmental issue, it has been the roofing industry that has packaged the solution and presented it to the consumer.
“Most facility managers are energy conscious, and they want to do what is best for the environment,” says Steve Ruth, director of sales for Duro-Last Roofing, Inc., a Saginaw, Mich.-based manufacturer of highly reflective and energy-efficient thermoplastic single-ply roofing systems. “But they also have a business to run and a budget to meet. Effecting change in their buying decisions takes a cost-effective, reality-based roofing solution that is also in line with helping the environment.”
According to the Lawrence Berkley National Lab’s Heat Island Group, the key to reducing a building’s heat envelope and thus the Heat Island Effect, is to maximize the reflectivity of the building materials used and deflect as much heat-causing radiation away from the structure as possible.
Furthermore, as the temperature of a building’s insulation rises, its R-value steadily decreases, which has even more of a detrimental effect on the building’s energy efficiency. When these problems are addressed, temperatures within the building can drop as much as 15 degrees.
The Heat Island Group has monitored buildings in Sacramento, Calif., having white, highly reflective roofs. They have found that these buildings used up to 40 percent less energy for cooling than buildings with darker roofs. The Florida Solar Energy Center has performed a similar study, also showing up to 40 percent cooling energy savings.
Additionally, white roofs retain their energy-saving advantages surprisingly far north. When winter solar intensity is compared to that of summer on a flat roof in a city the latitude of Boston, the savings can still be substantial. The bottom line is this: Because so little winter sunlight ever makes it to the roof in the first place, the reflectivity makes little difference in terms of winter heating. White, highly reflective roofing therefore allows buildings to be much cooler in summer, while only slightly colder in winter.
In the educational industry -- from boards of directors and administrators to facilities and maintenance personnel -- all would agree that improving the environment is just as vital a concern as educating today’s students to become tomorrow’s leaders. In most cases, this kind of environmental concern puts manufacturers, consumers and environmental groups at odds. But, when it comes to highly reflective, energy-efficient roofing products, for once, everyone is striving for the same results.
James Kehrer is a corporate account manager for Saginaw, Mich.-based Duro-Last Roofing, Inc.