Residential Roofing Solar Reflectance

How they can be made cool.

Residential roofing solar reflectance.

Solar reflective shingles and solar reflective roofing membranes can be an important component in a building system designed to reduce overall building energy consumption and the impact the home or building has on the environment. Unpainted metals are typically good solar reflectors but poor thermal emitters so they rarely satisfy low slope cool roof requirements. 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. Residential roofing options include asphalt shingles metal clay tiles and concrete tiles.

A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance. Solar reflective shingles. 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. Owens corning asphalt shingle products labeled as cool are rated with the cool roofing rating council ccrc for solar reflectance and thermal emittance.

Feature gaf proprietary color blends and enhanced shadow effect for a genuine wood shake look. Alternatively you can apply cool reflective coatings. The sr value is a number from 0 to 1 0. Solar reflectivity r solar reflectance index sri by color.

This is a requirement in some energy codes. 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. The most well known type of reflective surface is the cool roof. Reflective surfaces are a form of geoengineering.

Cambridge tm cool colors reflect a percentage. 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. Solar reflectivity or reflectance is the ability of a material to reflect solar energy from its surface back into the atmosphere. 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.

Meet the prescriptive solar reflectance and thermal emittance requirements according to the 2016 title 24 standards are rated by the cool roof rating council and meet the cool roof requirements of the los angeles green building code find out more about title 24 here. Painting a metal roof can increase its solar reflectance and thermal emittance allowing it to achieve cool roof status.