Solar Reflective Index (SRI) is important to understand when selecting a highly reflective roof coating that will help lower energy cooling costs. The SRI is a calculation method using solar reflectance and thermal emittance values to determine the roof’s overall capacity to refuse solar heat.
What is an SRI value?
SOLAR REFLECTANCE INDEX (SRI):
Incorporates both solar reflectance and thermal emissivity in a single value. 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.
What does Sri mean in construction?
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.
What is a good solar reflectance index?
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.
How do you calculate 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.
Is Higher Sri better?
Thermal emittance is the relative ability of a roof to emit (or release) heat that has been absorbed. Therefore, the higher the SRI value is, the greater ability the coating has to reject solar heat absorption, maintaining a cooler indoor ambient air temperature without the use of an air conditioning.
What is the most energy efficient roof color?
Light roofs are the most energy efficient roof color for summer, but remember that it’s not just roof color that comes into play here. Other factors such as roofing material, insulation, and the integrity and age of the roof all come into play.
What is the difference between SRI and Shree?
Shri Devi (or in short Shri, another name of Lakshmi, consort of Vishnu) is the devi (goddess) of wealth according to Hindu beliefs. Among today’s orthodox Vaishnavas, the English word “Shree” is a revered syllable and is used to refer to Lakshmi, while “Sri” or “Shri” is used to address humans.
What does Lanka mean?
The word Lanka simply means any island. It is still widely used by the aborigines of Central and Eastern India to mean an island and especially an islet in a river. The word is considered as belonging to Austro-asiatic languages.
What is Sri short for?
|SRI||Stanford Research Institute (now called SRI International)|
|SRI||Socially Responsible Investing|
|SRI||Space Research Institute|
|SRI||Summer Research Internship (various schools)|
Is a higher solar reflectance better?
Solar reflectance is the most important characteristic of a roof product in terms of yielding the highest energy savings during warmer months. The higher the solar reflective value the more efficient the product is in reflecting sunlight and heat away from the building and reducing roof temperature.
What is a cool roof system?
A cool roof is one that has been designed to reflect more sunlight and absorb less heat than a standard roof. … Standard or dark roofs can reach temperatures of 150°F or more in the summer sun. A cool roof under the same conditions could stay more than 50°F cooler and save energy and money by using less air conditioning.
How is solar reflectance calculated?
Solar reflectance: the range of solar reflectance is 0 – 1, with 0 for perfect black material and 1 for perfect white. If you know your material’s solar reflectance in percentage, simply convert it to decimal (e.g. 56.7% = 0.567). Emittance: it is often called emissivity.
What is the Sri value of concrete?
The LEED-NC Reference Guide7 provides a default emittance of 0.9 for concrete and solar reflectance values of 0.35 for “new typical gray concrete” and 0.7 for “new typical white concrete.” It also reports default SRI values for new gray and new white concrete of 35 and 86, respectively.
What is Sri in paint?
SRI is termed as solar reflective index and is used to determine the heat reflecting capacity or power of a roof cooling paint. The lower the SRI value, the hotter a material is likely to become in the sun.
What is solar reflection?
Solar reflectance (sometimes called albedo) is the ratio of solar energy that falls on a surface to the amount reflected. It is measured with a solar spectrum reflectometer on a scale of 0 (not reflective) to 1: (100 percent reflective).