When discussing cool roof coatings, you often hear the term solar reflectance index (SRI). As an example, Quartzene has been proven to be highly efficient in cool roof solutions, largely because of the material’s contribution to a high SRI value. But what does it mean to have a high value, and why is it so beneficial for coatings manufacturers?
A high value indicates high emissivity and reflectance of a material
SRI is a measure of the thermal emissivity and solar reflectance of a material. It is defined on a scale from 0 to 100. The higher the value of a material, the better it is at rejecting solar radiation to the atmosphere. The value also serves as an indicator of how hot the material is likely to get in direct sunlight. A high SRI indicates that the material will remain cool, even on a very hot summer day. Although the scale ranges from 0 to 100, extra cool materials may exceed this range.
A high value leads to more energy-efficient coatings
When the SRI value of a roof coating in a warm climate is low, it is likely that a lot of heat is absorbed by the roof and transferred into the building. High indoor temperatures increase the need for air conditioning, resulting in high energy consumption, costs, and carbon emissions. On the other hand, when using a coating with a high SRI, energy use is reduced, and indoor environments become more comfortable.
The high SRI of Quartzene has been evaluated externally
On behalf of Svenska Aerogel, Research Institutes of Sweden (RISE) has evaluated the SRI of Quartzene in a cool roof paint. The value of this example formulation was 123, which means that it rejected solar emission very well. Read more about Quartzene in cool roof solutions here.