The secret is in the granules.
To achieve a Solar Reflectance Index (SRI) of 20-plus, we embed surface granules that are specially designed with infrared-reflective pigments to transmit less of the sun’s solar energy or radiant heat into a home’s attic. This helps keep the home cooler and more energy-efficient.
Cambridge Cool Colors COOL PLUS and Cambridge Cool Colors COOL shingles have an SRI of 20 or greater, which is necessary to comply with the stringent roof reflectance requirements of the Los Angeles City and County Green Building Code.
Cambridge Cool Colors Natural Cool shingles have an SRI of 16 or greater. Thanks to their light color blends, they comply with California’s 2016 Title 24, Part 6, cool roof requirement, for other areas. Note that the Arctic White color blend exclusively has an SRI of 23 and can therefore be used in areas governed by the Los Angeles City and County Green Building Code.