Steel is probably ons of the worst materials for a heatsink precisely
for the reason you gave: it doesn't move heat well. For a heatsink, the
objective is to MOVE heat (this is why people with lots of heat to move
LOVE peltiers).
Remember, fans actually MAKE heat, but the reason they help cooling is
because they move the air around. This means that the hot air resulting
from the transfer of heat away from the sink is evacuated quickly and
cool air is brought in. Again, larger delta T means faster heat transfer.
--MonMotha
Joe Linux wrote:
We've sort of beat this subject to death, but I think what we are
looking for is a material that will quickly move the heat away from the
source (processor chip) and then quickly give it up to the air. My gut
feeling is that copper "holds" heat. whereas steel tends to give it up.
I used to build custom marine refrigeration systems and it seems to me
that when you solder a copper tube, the heat stays with it longer,
whereas with steel the heat doesn't travel the tube as much. It tends
to stay at the heat source and then cool down more quickly once the
flame is removed. It may have been said before, but the idea behind
fins is that they greatly increase the surface area and thus give up
more heat to the air. Actually fans always improve cooling. The issue
Wayne has is that he wants to eliminate the fan noise. Perhaps another
approach would be to continue with a fan in a case with good ducting but
concentrate on the noise reduction of the fans. It could be that these
fans have resonate frequencies that are sympathetic with the case so
it's possible that some sound deadening material applied to the outside
of the case could greatly improve the situation.
