Ricardo B (ricardo.b@xxxxx.xx) on 6/24/11 wrote:
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>I'm afraid you're quite wrong.
>It's not a mere matter of air flow.
>
>Besides airflow, there are two more key parameters in the transfer of heat to air:
>the contact area and the temperature difference between the contact area and the air.
>
>In order to maximize heat radiation you want your heat sink to have as much contact
>area as possible. Thus, the heat sink designs with lots of big fins.
>
>However, there's a catch. The material's (aluminium, copper) thermal resistance will produce a temperature gradient.
>That is, the heatsink will always be hotter at the base and cooler at the edges.
>
>This means that increasing the contact area has diminishing benefits: you increase
>area, but a greater part of that are is cooler and radiates less heat.
>
>Enter water cooling.
>With a circulating fluid, like water or oil, the temperature gradients are much smaller.
>In turn, this allows for radically different radiator designs, with a much larger and effective contact area.

What about heat pipes? They do basically the same, but without forcing
you to use a complex system to control the fluid, are a closed system
and can be used with passive cooling.