Green Roof Albedo

This roof has a high albedo and reflects about 63 of the energy from sunlight.

Green roof albedo.

In contrast to conventional roofs these kind are specifically designed to reduce internal building temperature by reflecting the sun s uv rays. The solar reflectance of green roofs varies depending on the plant types generally 0 3 0 5. Albedo is the reflecting power of a surface. 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.

A sample. 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. In los angeles the average roof albedo is about 0 17. It recorded an albedo decrease of 0 15 in a year gaffin et al 2006.

On a sunny day a roof that strongly reflects sunlight can stay much cooler than a roof that absorbs sunlight. Green roofs provide a thermal mass layer which helps reduce the flow of heat into a building. White paint recorded an albedo of 0 8 on average but it is difficult to maintain high albedos on white surfaces without regular washing. A sample cool roof.

2006 conducted a research comparing surface radiation reflectivity albedo of white roofs and green roofs. 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.