Since ancient times, people in areas with hot climates have opted for brightly colored roofs that reflect sunlight with a view to keeping their indoor spaces cool. White or bright-hued surfaces are naturally great at reflecting heat, but cooling rooms below is another story. Now, engineers at Stanford University have come up with a new twist to this basic premise. Instead of merely relying on roof color, they created a multilayer coating that simultaneously reflects most incoming sunlight and absorbs heat, which is then discharged away.
A group of Stanford University researchers set off to create a mirrored coating that also radiated energy at long wavelengths. The scientists, however, admit that no natural material exists that both reflects solar wavelengths and remains radiative in thermal wavelengths. The trick lies in structuring a surface that would reflect lower and upper ranges while discharging microwaves that can’t be absorbed by air.
Such an idea has yet to prove feasible, however. Fortunately, homeowners can turn to a trusted roofing company in Palo Alto—such as Shelton Roofing, for instance—for proven roofing solutions that are stylish and durable, not to mention energy efficient. A “cool roof”, for instance, is designed to reflect the sun’s rays away and keep the spaces below cool, thereby leading to a reduction in cooling costs. Not any white roof would work, however. Instead of mere asphalt shingles painted white, it would be best to go with a metal roof.
Another option is to make use of wood shingles and shakes. These materials are typically made from old-growth western cedar. The downside is that these materials are flammable and may not be used in areas where the incidence of forest fires is rather high. In addition, wooden roofs last up to 25 years on average, compared to metal roofs that can stand intact for up to 50 years.
At any rate, the most eco-friendly cool roofing option of all Palo Alto roofing materials would be recycled shingles. These shingles are made from recycled waste materials, such as rubber, wood fiber, or plastic. Some may be made post-consumer waste and some from post-industrial waste. These are highly durable and come with warranties of up to 50 years.
(Source: A new way to cool, Science Mag, November 26, 2014)