Wednesday, September 1, 2010

Solar radiation absorbed by various materials

Absorbed Solar Radiation by Surface Color

In general the solar energy absorbed can be approximated by the surface color
Surface Color Absorb Factor - Fraction of Incident Radiation Absorbed
(approximated)
White smooth surfaces 0.25 - 0.40
Grey to dark grey 0.40 - 0.50
Green, red and brown 0.50 - 0.70
Dark brown to blue 0.70 - 0.80
Dark blue to black 0.80 - 0.90

Absorbed Solar Radiation by Material

Substance Absorb Factor  - Fraction of Incident Radiation Absorbed
Aluminum, polished 0.30
Aluminum paint 0.20
Aluminum, anodized 0.15
Brick, glazed 0.35
Brick, common light red 0.55
Brick, common red 0.68
Brick, wire cut red 0.52
Brick, blue 0.89
Cork 0.45
Limestone, light 0.35
Limestone, dark 0.50
Linoleum, red-brown 0.84
Sandstone, light grey 0.62
Sandstone, red 0.73
Marble, white 0.44
Soft rubber, gray 0.65
Marble, dark 0.66
Granite, reddish 0.55
Magnesium oxide, evaporated 0.08
Graphite 0.84
Porcelain 0.50
Steel, vitreous enameled green 0.76
Steel, vitreous enameled dark red 0.81
Steel, vitreous enameled blue 0.80
Iron, galvanized new 0.64
Iron, galvanized dirty 0.92
Iron, galvanized white washed 0.22
Concrete 0.60
Copper, polished 0.18
Copper, tarnished 0.64
Lead, old 0.79
Asbestos cement, roof tiles old 0.83
Asbestos cement, roof tiles red 0.69
Asbestos slate 0.81
Asphalt roofing, new 0.91
Asphalt roofing, old 0.82
Bitumen-covered roofing sheet, brown 0.87
Slate, blue grey 0.87
Tile, clay red 0.64
Tile, concrete uncolored 0.65
Tile, concrete black 0.91
Vitreous enamel, white 0.39
White Dutch tile 0.18

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