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. This roof has a high albedo and reflects about 63 of the energy from sunlight. The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. In contrast to conventional roofs these kind are specifically designed to reduce internal building temperature by reflecting the sun s uv rays. White paint recorded an albedo of 0 8 on average but it is difficult to maintain high albedos on white surfaces without regular washing.

The albedo effect has been proven in both natural and man made environments in recent years. Click on the green marker to view this building in google maps. On a sunny day a roof that strongly reflects sunlight can stay much cooler than a roof that absorbs sunlight. 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.

2006 conducted a research comparing surface radiation reflectivity albedo of white roofs and green roofs. Albedo is the reflecting power of a surface. A sample cool roof. In los angeles the average roof albedo is about 0 17.

Green roofs may not reflect as much as a cool roof but do have other benefits such as evapotranspiration which cools the plants and the immediate area around the plants aiding in lowering rooftop. It recorded an albedo decrease of 0 15 in a year gaffin et al 2006.