Sri Value Of Roofing Materials

The third metric used to measure the performance of cool roof coverings is called the solar reflectance index sri.

Sri value of roofing materials. 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. 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. Solar reflectance index sri. This measurement can be used as an indicator of how hot shingles are likely to become when they re exposed to the sun.

This measure is calculated from the tsr and te. Te is also measured from 0 to 1. The higher the sri the cooler the roof will be. A value of 0 indicates that the material absorbs all solar energy and a value of 1 0 indicates total reflectance.

The solar reflectance index or sri is a calculation using the aged solar reflectance and thermal emittance measurements of the asphalt shingles materials. The higher the value the more heat the material emits. Different roofing technologies have different sri values. 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.

Asphalt coatings for example have aluminum pigments added to asphalt cutbacks and emulsions to give coatings solar reflectance index sri values of 21 30 on a scale of 0 100. Sri can be calculated based on the pitch of a roof its weight its solar reflectance thermal emittance emissivity and its ageing characteristics. 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. Energy star requires an initial sr value of 0 25 or higher for steep slope 2 12 roofs and 0 15 or greater after three years.

Recycled content of berridge metal. The sr value is a number from 0 to 1 0. Nb this definition means that it is possible to have materials with an sri of less than 0 or more than 100. It ranges from 0 to 100.