Green Roof Reflectivity

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 reflectivity.

Leaf reflectivity the fraction of incident solar radiation that is reflected by the individual leaf surfaces. Buy cool asphalt shingles which use specially coated granules that provide better solar reflectance. Green building council and has been mandated by government officials in chicago. Commonly referred to as cool roofing it has received a stamp of approval from the state of california which has adopted its use in its building codes.

Green roofs provide a thermal mass layer which helps reduce the flow of heat into a building. Shingle roofs consist of overlapping panels made from a variety of materials such as fiberglass asphalt wood polymers or metals. Still cool neutrals such as medium and muted green. 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.

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. White or reflective roofs have been in use for the past 15 years. This is a very unfortunate misconception. Cool roofs by chris wark energy editor originally posted march 2 2011.

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. Solar radiation includes the visible spectrum as well as infrared and ultraviolet wavelengths. 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.

Green roof tab materials d ialog. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance. How they can be made cool. Solar reflectivity or reflectance is the ability of a material to reflect solar energy from its surface back into the atmosphere.

It has become a leed leadership in energy and environmental design standard of the u s. Berridge s kynar 500 hylar 5000. Cool metal roof colors are optimal for reducing energy consumption particularly where cooling loads dominate. The sr value is a number from 0 to 1 0.

By rich thomas leed ap and steven h. Solar reflectivity r solar reflectance index sri by color. The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. Coating existing asphalt shingles to make them cool however is not normally recommended or approved by shingle manufacturers.

Images courtesy boral roofing. 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.