Green Roof Albedo

Roof surface temperature for the plain concrete roof con the white coated concrete roof wh con the white coated roof with 25 smaller albedo old wh con the green roof gr r the pond.

Green roof albedo.

Albedo or solar reflectance is a measure of a material s ability to reflect sunlight including the visible infrared and ultraviolet wavelengths on a scale of 0 to 1 an albedo of 0 0 indicates that the surface absorbs all solar radiation and an albedo of 1 0 represents total reflectivity. Sustainable roofing glossary albedo. In contrast to conventional roofs these kind are specifically designed to reduce internal building temperature by reflecting the sun s uv rays. 2006 conducted a research comparing surface radiation reflectivity albedo of white roofs and green roofs.

Using what s known as a climatological model one 50 year study undergone in new york city has evaluated the results of surface albedo of green roofs compared to black ones. White paint recorded an albedo of 0 8 on average but it is difficult to maintain high albedos on white surfaces without regular washing. In nature white sea ice melting into the dark blue ocean in cities formerly green enviroments being covered with pavement and skyscrapers with black rooftops in cities the earth is slowly being covered. It recorded an albedo decrease of 0 15 in a year gaffin et al 2006.

The majority of the roofs in the world are dark coloured and as a result have a low albedo and absorp excessive amounts of heat. Albedo is a unitless measure with possible values ranging from 0 to 1. Therefore in order to evaluate the effects on the climate change we have translated the difference of albedos between the black membrane and the two other roofing systems into avoided kilograms of co 2. Green roofs however have a much higher albedo thus helping to reduce the warming of surrounding air by reflecting much more of the sun s radiation.

Keep your commercial building cool with a cool roof one of the more recent advancements in the field of green commercial construction are what are known as cool or albedo roofs. Green roofs typically have an albedo of 0 7 to 0 85 an albedo comparable to the 0 8 of white roofs gaffin et al 2006. Ultimately the albedo of a green roof is about twice higher than the albedos found for dark roofing surfaces klein coffman. Albedo is the reflecting power of a surface.

And how your roof can help fight climate change. Objects that reflect lots of light have a high albedo approaching 1 while a perfect black body would have an albedo of 0. In order to evaluate the surface albedo of the green roof we monitored the roof and we found an average albedo of 0 2 gaffin et al 2009. Green roofs mitigate urban heat island effect acacia smith explains the albedo effect.