Roofs With A Solar Reflectanace Of 4 Or Greater

Ul evaluates solar reflectance roof covering materials using requirements developed by many sources.

Roofs with a solar reflectanace of 4 or greater.

The effectiveness of a cool roof is measured by solar reflectance and thermal emittance. Emittance on the other hand refers to the roofing material s ability to shed heat rather than retain it. It helps protect it from the elements and impacts its overall exterior look and curb appeal further an asphalt shingle roof can potentially deliver energy saving benefits when cool asphalt shingles are installed. Usually the visible reflectance is correlated with the solar reflectance but the two quantities are not equal.

One of the biggest factors in energy efficiency in bryan roofing is the ability of the roofing material to reflect solar energy. For example a good white coating with a solar reflectance of 0 8 typically has a visible reflectance of about 0 9. As temperatures warm around the brazos valley many home owners take the opportunity to reroof their old roof for a roofing system that is more energy efficient. Just like reflectance the emittance of the roof is measured on a scale of 0 to 1 with 1 being the highest.

This is the reflectance in the visual part of the solar spectrum wavelengths of 400 to 700 nanometers. In a study by shiao and kalkanoglu during the. These shingles are engineered to have higher solar reflectance and thermal emittance properties that can. This is also tied to thermal resistance of a roof as well.

As such it plays an equal if not greater role in defining what s a truly energy efficient roof. Both properties are measured individually from 0 to 1 0 with 1 0 being the material with the best performance. Solar reflective shingles are designed specifically to reduce the absorption of the suns infrared radiation by reflecting ir rays off the surface of the roof thus not allowing the heat to be transferred to the interior of the structure i e.