Solar Reflectance Green Roof

The sr value is a number from 0 to 1 0.

Solar reflectance green roof.

Solar reflectance index sri. Sri measures the roof s ability to reject solar heat defined such that a standard black reflectance 0 05 emittance 0 90 is 0 and a standard white reflectance 0 80 emittance 0 90 is 100. Green roofs provide a thermal mass layer which helps reduce the flow of heat into a building. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance.

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. Shingle roofs consist of overlapping panels made from a variety of materials such as fiberglass asphalt wood polymers or metals. The solar reflectance index sri is a measure of the constructed surface s ability to reflect solar heat as shown by a small temperature rise. It is defined so that a standard black reflectance 0 05 emittance 0 90 is 0 and a standard white reflectance 0 80 emittance 0 90 is.

The us department of energy defines the solar reflectance index sri as a measure of the roof s ability to reject solar heat as shown by a small temperature rise. Buy cool asphalt shingles which use specially coated granules that provide better solar reflectance. How they can be made cool. It is defined so that a standard black surface reflectance 0 05 emittance 0 90 is 0 and a standard white surface reflectance 0 80 emittance 0 90 is 100.

The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. Solar reflectivity r solar reflectance index sri by color.