TSR Levels on Infra-Red Cool Coating

One of the many roofing services that we offer here at Wilcote is infra-red cool coating, which is an innovative technology that helps to provide cooling to buildings and structures. This technology has been proven to be extremely effective in preventing urban ‘heat islands’ – an occurrence that is caused by the sun’s rays reflecting on manmade surfaces such as roofs, which in turn results in increased temperatures.

A very important part in the effective usage of infra-red roof cooling lies in ensuring that products and technology used in the process meets certain standards. TSR (Total Solar Reflectance) measurements are used to meet these standards, and measure the amount of solar radiation that is reflected by the sun.

Before we discuss TSR levels and their importance, it is first a good idea to understand exactly why infra-red coating for roof cooling is becoming essential in our cities and towns.

Temperature increases in densely populated areas is thought to be caused by air pollution to some degree, but the sun’s rays that are absorbed by buildings also plays a major role in this heating process. The light reflectance value of roof coatings and paints used on buildings has a direct effect on how these rays are absorbed. Technology suchas infra-red has been successfully used in many different instances, but in the paint and roofing industry, it has proven to have significant impact on reducing the amount of heat absorbed by coated surfaces.

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What Are TSR Measurements?

Simply put, Total Solar Reflectance (TSR) uses a percentage or decimal figure to show the amount of infra-red radiation that is reflected from a surface, such as a roof. The higher the TSR level, the higher the reflectance. Roofing companies and paint and coating manufacturers need to be aware of these levels before they are able to make claims on how much light can be reflected by the products they offer. Light reflectance levels are measured through visible and invisible colour spectrums – particularly the infra-red spectrum where light is absorbed. Needless to say, it is impossible to measure such levels by the human eye. Instead, special measurement tools are used.

Through the use of standards that govern TSR measurements, and the use of colour measurement tools that allow these levels to be accurately measured, it is possible to determine the exact value of TSR in roof coating products. These measurements are based on US standards that differ from SABS standards used in South Africa.

Measuring tools include the Solar Spectrum Reflectometer, which features a selectable solar measurement spectrum that correlates to standard global and beam normal solar irradiance models. This tool delivers accurate measurements on various materials, including surface reflectors as thick as 6.4mm. Solar reflectance or absorptance is shown to 0.001 units, with a 0.003 unit repeatability.

How Do TSR Levels Affect Infra-Red Cool Coating Products?

TSR levels on all Wilcote infra-red cool coat products meet the following US standards:

  • ASTM C1549. Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer.
  • ASTM E903. Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres.
  • ASTM E891. Tables for Terrestrial Direct Normal Solar Spectral Irradiance Tables for Air Mass 1.5.

Learn more about our infra-red roof cooling technology to see exactly how it works, and contact us if you have any queries at all regarding these innovative solutions.

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