Metal Roof Solar Reflectance

A cool metal roof with high solar reflectance and high thermal emittance would have a lower surface temperature as compared to a roof with low reflectance and low emittance.

Metal roof solar 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. Leed requires a roofing material to have a value of 29 or higher for a steep roof pitch 2 12 and 78 or higher for a roof pitch 2 12. Steep slope roofs must have an initial solar reflectance of 0 25. Cool metal roofing coated with kynar 500 based resin is one way to limit the urban heat island effect.

The sr value is a number from 0 to 1 0. Cool metal roof colors are optimal for reducing energy consumption particularly where cooling loads dominate. The benefits of cool metal roofing cool metal roofing has many benefits beyond savings on energy costs. Berridge s kynar 500 hylar 5000.

After 3 years the solar reflectance must be 0 15. Many cool metal roofing systems are also energy star certified and may qualify for tax incentives. Only those roof products that meet the specifications listed in either table 1 or table 2 below may qualify as energy star qualified. Cool metal roofing systems help reduce the energy need of air conditioned buildings and makes unconditioned buildings more comfortable.

Berridge metal roofing is cool and sustainable the high reflectivity emissivity and solar reflectance index sri of berridge metal roofing helps mitigate the heat island effect. The cool metal roofing paint resin formula formulated by sherwin williams or another paint supplier contains innovative solar reflective pigments which is the key differentiator. How they can be made cool. In the case of a cool metal roof a lower surface temperature translates into less heat gain into the attic space or living space below the roof.

Kynar 500 based painted metal roofing can achieve solar reflectance of over 70. This highly reflective coating uses cool pigments in the paint to increase solar reflectance and lower the surface temperature of the roof. The most effective energy saving finish for metal roofing is commonly referred to as cool metal roofing. Unpainted metals are typically good solar reflectors but poor thermal emitters so they rarely satisfy low slope cool roof requirements.

Also important characteristic to a metal building panel color is the ability of the panel to release absorbed energy called emissivity. This is called the solar reflectivity index sri. Painting a metal roof can increase its solar reflectance and thermal emittance allowing it to achieve cool roof status. Alternatively you can apply cool reflective coatings.