Green Roof Reflectivity

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.

Green roof reflectivity.

Still cool neutrals such as medium and muted green. Still the shine of bright white on a roof is imposing and can take away from the overall aesthetic of the house. 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. 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.

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. It has become a leed leadership in energy and environmental design standard of the u s. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance. 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.

Solar radiation includes the visible spectrum as well as infrared and ultraviolet wavelengths. By rich thomas leed ap and steven h. Buy cool asphalt shingles which use specially coated granules that provide better solar reflectance. White or reflective roofs have been in use for the past 15 years.

The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. Green building council and has been mandated by government officials in chicago. Solar reflectivity or reflectance is the ability of a material to reflect solar energy from its surface back into the atmosphere. Cool roofs by chris wark energy editor originally posted march 2 2011.

The sr value is a number from 0 to 1 0. Green roofs provide a thermal mass layer which helps reduce the flow of heat into a building. 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. Green roof tab materials d ialog.

Another option is a vegetative roof that holds plant life and reduces reflective heat. Solar reflectivity r solar reflectance index sri by color. How they can be made cool. Leaf reflectivity the fraction of incident solar radiation that is reflected by the individual leaf surfaces.

Green roof energy series part 6. Shingle roofs consist of overlapping panels made from a variety of materials such as fiberglass asphalt wood polymers or metals. This is a very unfortunate misconception. Values for this field must be between 0 1 and 0 4.

Cool metal roof colors are optimal for reducing energy consumption particularly where cooling loads dominate. 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.