Green Roof Reflectivity

Green roofs may not reflect as much as a cool roof but do have other benefits such as evapotranspiration which cools the plants and the immediate area around the plants aiding in lowering rooftop.

Green roof reflectivity.

Green roofs provide a thermal mass layer which helps reduce the flow of heat into a building. Green and cool roofs help buildings in highly populated areas stay cool by elevating the heat island effect streets parking lots and rooftops contribute to the heat island effect and can bring roof surface temperatures up to 70 degrees hotter than the. Green roof tab materials d ialog. Still the shine of bright white on a roof is imposing and can take away from the overall aesthetic of the house.

How they can be made cool. The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. Shingle roofs consist of overlapping panels made from a variety of materials such as fiberglass asphalt wood polymers or metals. Berridge metal roofing is cool and sustainable the high reflectivity emissivity and solar reflectance index sri of berridge metal roofing helps mitigate the heat island effect.

Leaf reflectivity the fraction of incident solar radiation that is reflected by the individual leaf surfaces. Green building council and has been mandated by government officials in chicago. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance. Images courtesy boral roofing.

Still cool neutrals such as medium and muted green. This is a very unfortunate misconception. Another option is a vegetative roof that holds plant life and reduces reflective heat. Cool roofs are pretty cool but whether or not they save as much energy as a green roof requires as usual a closer look at a a cool roof and b a given green roof design.

Berridge s kynar 500 hylar 5000. Cool roofs by chris wark energy editor originally posted march 2 2011. It has become a leed leadership in energy and environmental design standard of the u s. Cool metal roof colors are optimal for reducing energy consumption particularly where cooling loads dominate.

Values for this field must be between 0 1 and 0 4. Buy cool asphalt shingles which use specially coated granules that provide better solar reflectance. Solar radiation includes the visible spectrum as well as infrared and ultraviolet wavelengths. Coating existing asphalt shingles to make them cool however is not normally recommended or approved by shingle manufacturers.

Solar reflectivity r solar reflectance index sri by color. White is the most reflective color and white metal roofing can actually lower the ambient temperature in the home by reflecting more of the sun s rays into the environment. By rich thomas leed ap and steven h. Green roof energy series part 6.

The sr value is a number from 0 to 1 0. Miller cdt to many design professionals the term cool roof means a flat roof with a white membrane a high reflectance roof that performs well but needs to be hidden from view.