Benefits of Cool Roofing
While there is some concern that cool roofing has been over-promoted at the expense of insulation, there is little doubt among the technical community that reflective roofing surfaces, used in tandem with roofing insulation, is a powerful tool for reducing energy consumption and improving the environment nationwide. Numerous studies and real-world experience have proven that high-performance cool roofing systems not only help reduce annual energy consumption in buildings by 15 to 45 percent, depending on building design, climate and other factors, they can also:
–Improve the performance of the underlying insulation. High surface temperatures lower the effective R-value of most types of insulation in use today. Because cool roofing surfaces are up to 80 degrees cooler than black surfaces on hot days, studies have shown that insulation underneath can be 25 to 50 percent more effective at resisting thermal conductivity under summer heat loads.
–Extend the useful life of the roof. Deterioration of roof substrates is accelerated by ultraviolet (UV) radiation, infrared (IR) radiation and moisture penetration. Studies have found that the rate of deterioration of substrate materials can be slowed by as much as 75 percent when a cool roofing system is used. Cool roofing systems slow the rate of degradation by reflecting UV radiation, by reflecting heat-generating IR radiation, and by preventing moisture penetration.
–Reduce the capacity requirements for a building’s HVAC system. Most HVAC units have efficiency ratings performed at 950 F. As rooftop temperatures rise above 950 F, rooftop air conditioning efficiency drops. On hot days, it is not uncommon for black roof surface temperatures to reach 180 degrees or more. Cool roof surface temperatures under the same conditions are up to 80 degrees cooler. With traditional black roofs, the HVAC inlet air temperature at 30 inches above the roof surface can be up to 15 degrees hotter than reflective cool roofs. This is why cool roofing systems enable rooftop cooling equipment to run more efficiently, and may reduce the cooling equipment capacity requirements.
–Contribute to better indoor air quality and comfort. Indoor comfort can be improved dramatically by cool roofing systems in buildings that are not climate-controlled. Inside temperatures typically run 15 to 20 degrees cooler under a reflective roof membrane, improving occupant comfort and productivity while keeping building contents cooler.
For more information on Cool Roofing, visit www.duro-last.com