Residential Roofing Solar Reflectance

Alternatively you can apply cool reflective coatings.

Residential roofing solar reflectance.

Feature gaf proprietary color blends and enhanced shadow effect for a genuine wood shake look. Solar reflectivity or reflectance is the ability of a material to reflect solar energy from its surface back into the atmosphere. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance. Solar reflective shingles.

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. Painting a metal roof can increase its solar reflectance and thermal emittance allowing it to achieve cool roof status. The most well known type of reflective surface is the cool roof. Unpainted metals are typically good solar reflectors but poor thermal emitters so they rarely satisfy low slope cool roof requirements.

This is a requirement in some energy codes. The sr value is a number from 0 to 1 0. Owens corning asphalt shingle products labeled as cool are rated with the cool roofing rating council ccrc for solar reflectance and thermal emittance. Solar reflectivity r solar reflectance index sri by color.

California s building energy efficiency standards for residential and nonresidential buildings title 24 part 6 contains requirements for the thermal emittance three year aged reflectance and solar reflectance index sri of roofing materials used in new construction and re roofing projects. All of these types of residential roofing products are now available with ir reflective color pigments which act to reduce the temperature of roofs and reflect heat away from the home. 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. How they can be made cool.

Innate reflectance is measured on a scale from 0 to 1 with the latter being the highest level of reflectivity meaning it reflects 100 of all radiant energy coming in contact with it. As you re shopping for your new roof look for the tag or label solar reflectance. Reflective surfaces are a form of geoengineering. Residential roofing options include asphalt shingles metal clay tiles and concrete tiles.

Reflective surfaces can deliver high solar reflectance the ability to reflect the visible infrared and ultraviolet wavelengths of the sun reducing heat transfer to the surface and high thermal emittance the ability to radiate absorbed or non reflected solar energy. Cambridge tm cool colors reflect a percentage.