Cool roofs are roofs that are designed to maintain a lower roof temperature than traditional roofs while the sun is shining. Cool roofs have surfaces that reflect sunlight and emit heat more efficiently than hot or dark roofs, keeping them cooler in the sun. In contrast, hot roofs absorb much more solar energy than cool roofs, making them hotter.
Since most dark roofs absorb 90% or more of the incoming solar energy, the roof can reach temperatures higher than 150°F (66ºC) when it’s warm and sunny. Higher roof temperatures increase the heat flow into the building, causing the air conditioning system to work harder and use more energy in summertime. In contrast, light-colored roofs absorb less than 50% of the solar energy, reducing the roof temperature and decreasing air conditioning energy use.
Cool roof requirements depend on the roof’s slope. Low sloped roofs have a pitch of 9.5° or less. Single-ply membranes are pre-fabricated sheets that are rolled onto the roof and attached with mechanical fasteners, adhered with chemical adhesives, or held in place with ballast (gravel, stones, or pavers). Some kinds of membranes, like TPO and PVC, are typically white and reflect sunlight well.
CertainTeed’s ENERGY STAR® Rated Roofing Products are more energy-efficient than standard roofing products by
exceeding ENERGY STAR standards in both solar reflectance and thermal emissivity.
HOW MUCH WILL YOU SAVE?
Cool roofs can save money in several ways, including energy savings, rebates and incentives, HVAC equipment downsizing, and extended roof lifetime.
Commercial buildings account for more than 33% of the total energy consumption in the United States every year and are responsible for over 65% of yearly electricity costs.
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Swadley Roof Systems is also a member of the Cool Roof Rating Council (CRRC).