What is the material used to get high SRI?

SRI is a scale from 0 to 100 on which materials that absorb and retain solar radiation (and so become hotter in sunshine) have a lower number, whilst highly reflective materials (which remain cooler in sunshine) have a higher number. The US department of energy defines the Solar Reflectance Index (SRI.)

How do you measure SRI?

SRI is calculated with a complex formula spelled out in ASTM E 1980 and is a scale of 1 to 100 that is a measure of a roof’s combined thermal properties. 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 100.

How is solar reflectance index tested?

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 surface (reflectance 0.05, emittance 0.90) is 0 and a standard white surface (reflectance 0.80, emittance 0.90) is 100.

How is the Solar Reflectance Index used in the built environment?

Solar Reflectance Index in the built environment. The Solar Reflectance Index (SRI) is a measure of the solar reflectance and emissivity of materials that can be used as an indicator of how hot they are likely to become when solar radiation is incident on their surface.

What is the reflectance index of a roof?

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. It is defined so that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80,…

What is the solar reflectance of a roof?

Solar reflectance (SR) is the ratio between the solar energy globally reflected by a surface and the total incident solar energy. Traditionally, roofing materials’ SR can be between 0.05 and 0.5 (e.g., 0.05 for black membrane roofs, 0.08–0.5 for metal roofs, and 0.2 for clay tiles).

What is the SR value for solar reflectance?

A value of 0 indicates that the material absorbs all solar energy and a value of 1.0 indicates total reflectance. 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.