The latest trend in flat roofs is the " cool roof" design. These roofs reflect light and stay cooler vs. historically black roofs, absorbing heat, causing AC units and cooling towers to work harder.Cool Roofs use roofing materials that are highly reflective (also called high albedo roofs) of the sun’s radiant heat. They may also have a high thermal emittance value. Emittance is a measure of how much of the absorbed radiant energy is given off into the atmosphere - keeping the surface cooler as a result.
One of the issues given enormous attention in the last few years is the usage of Cool Roofs to mitigate the Urban Heat Island effect. The Urban Heat Island effect is the creation of higher ambient temperatures in densely compacted urban areas than the surrounding suburban areas. It is a result from reduced vegetative growth as well as a higher incidence rate of black or dark colored pavement and roofing.
Typically, Cool Roofs are those with a solar reflectance value of 0.65 or higher when new. That means 65% of the total radiant heat energy is reflected back into the atmosphere.
Legacy Industrial, A Clean Seal LLC Company sells a variety of roof coatings that can be used to create a "cool roof" . 908-269-8300 or www.legacyindustrial.net
Cool roof information was borrowed from an article posted by Centimark Corp.