S. J. Blackwell wrote:
> Tom,
> I agree with your statements below. The color has very little to do with
> heat sinks that we deal with.
>
> Most heat sinks now days have relatively tall closely spaced fins. For
> practical porposes the heat sink, from a radiation stand point, could be
> looked at as a block of material the length, width and height that would not
> include the fins. The only radiation heat loss for all practical purposes
> would be from top, bottom and sides. Little radiation loss from the fins as
> they face each other.
> They are clearly designed for an air flow over the
> fins. Paint, in my veiw, would impede cooling, no matter what color. Anodize
> is another matter. Anyone for black anodized bottom, pink fins except the
> outside surfaces of the first and last fins and the fin edges? Arrange the
> heat sink for good convection, if that is not sufficient, then blow it, pink
> or not. It doesen't matter. For all practical purposes the black body does
> not include the fins.
>
> 73
> Sam, W5LU
I think you will find the *radiation* from a heat sink is going to be
very small indeed. It will not depend the slightest on airflow.
*Convection* will be the dominant method of loosing heat, which will
depend on airflow.
Simple explanation at:
http://www.mansfieldct.org/schools/MMS/staff/hand/convcondrad.htm
More complex one at:
http://sol.sci.uop.edu/~jfalward/heattransfer/heattransfer.html
No doubt 100's more explanations on the web too.
As such, I'm not convinced blacking the heat sinks will do much for
cooling, especially if there is even a very small fan nearby.
--
Dr. David Kirkby
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|