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Old 12-20-2011, 01:57 PM   #15 (permalink)
ConnClark
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Quote:
Originally Posted by California98Civic View Post
I didn't. It's about appearance. Only top side is painted. Why worse?
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Black body emissivity is a measurement of how well something absorbs or emits light radiation. If you have a heat shield between something hot and something you want cool and paint it black, it will absorb the IR heat from the hot side and radiate it on the cold side thus heating what your trying to keep cool.

Emissivity - Wikipedia, the free encyclopedia

here is a table of emissivity for different surfaces.

http://www.monarchserver.com/TableofEmissivity.pdf

A bare aluminum heat shield is better than something that is painted. Ideally you would want a heat shield coated in polished silver.
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