Rubber Roofing – BLACK OR WHITE?

The following information is excerpted from “ENERGYEFFICIENT CARLISLE SYNTEC SYSTEMS ROOFING: MORE THAN A SIMPLE BLACK AND WHITE ISSUE” by Carlisle-Sysntec.

A full review of the article may be viewed HERE.

 

The days when heating and cooling costs were a relatively insignificant line item on a building owner’s budget are long gone. Oil prices, though lower than they were earlier in the year, remain high and extremely unstable. Natural gas and coal prices are also on the rise. All of these increases and instability have led to higher heating and cooling costs, and property

owners are doing all they can to keep them in check through the use of energy-efficient building materials.

An argument can be made that the focus on energy efficiency has impacted the roofing industry more than most. Numerous codes have been developed, organizations formed and regulations established—all in the interest of addressing the issue of energy efficient roofing. Over the past decade, energy efficiency within the roofing market has been focused on cool roofing, which utilizes light-colored materials such as thermoplastic polyolefin (TPO) to reflect sunlight and solar energy away from a building and keep it cooler.

It has been proven through numerous studies that, under some circumstances, a building’s air conditioning-related energy consumption can be reduced through the use of reflective roofing materials. These studies, along with some irresponsible marketing efforts, have helped create a perception within the roofing industry that reflectivity is the best option for reducing energy consumption.

But, there is a catch with that philosophy and caution must be used when specifying cool-roof systems. The energy savings that buildings experience due to the use of reflective roofing materials are most often realized in warm, southern climates where Cooling Degree Days (CDD) outnumber Heating Degree Days (HDD) and air conditioning is more prevalent than heating. To help reduce heating-related energy demands, which are greater than air conditioning demands in northern regions, dark-colored materials such as EPDM membranes are most often beneficial. That is because materials like EPDM absorb heat and transfer exterior solar energy into a building, causing interior temperatures to rise, helping to alleviate the demands placed on heating systems.

Unfortunately, there continues to be a misconception throughout much of the industry that reflective roofing is the panacea for our buildings’ energy woes regardless of geographical location. This could not be further from the truth. If looked at strictly from an energy-efficiency perspective, research and data prove that materials like EPDM can provide the same, or better, energy savings as a light-colored alternative in many locations.

The numbers indicate that the move toward reflective roofing in many parts of the country may be unwarranted, and in fact, counterproductive to the goal of minimizing overall energy consumption. The numbers also suggest that there should be more focus on cutting heating costs, and not cooling costs, which makes dark-colored membranes such as EPDM an important asset in the push for energy efficiency. The U.S. Department of Energy (DOE), in conjunction with its research wing the Oak Ridge National Laboratory (ORNL), has developed a Cool Roof Calculator to help consultants, architects, roofing contractors and building owners determine the most efficient and cost-effective roof system for any given project. Accessible through the DOE web site, the Cool Roof Calculator simulates building energy consumption based on the type of roofing membrane and amount of insulation that is installed.

Users can pinpoint the analysis within the Cool Roof Calculator based on the zip code of their project, resulting in direct, head-to-head comparisons of various roofing assemblies. In most instances, dark colored membranes will prove to be more energy efficient than light-colored materials for projects located in cooler climates.

 

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