Roy wrote:
> Black bodies radiate and absorb heat many times
> more efficiently than a white or shiny body.
I have heard it said that this is largely true at extreme
temperatures. Might be nice to have someone dissipate a
"real world" amount of power (say 100 watts) in a heat
sink of raw aluminum and do it again with an identical
sink that is black. I have a hunch that the heatsinks will
have similar temperatures.
Check out this website for a pretty good discussion of emissivity of heat.
You might be surprised to see what a difference the material and color
makes.
http://x26.com/irpaper_emissivity.htm
The emissivity of anodized aluminum is typically very poor. The same
material painted flat black is very good.
> Try wearing a nice black tee shirt in the direct sun as
> compared to a white one.
Absolutely no question here but isn't this a case of
absorbing heat as opposed to radiating it?
The property applies in both cases
- Jim WB6BLD
Steve
KT4FY
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