Cooling

Cooling

Part of the original concept was to make this machine as quiet as possible so fan-less cooling is a must.

The Pentium 4 M kicks out about 30 watts under normal load, the Celeron about 45 watts. Fan-less cooling will require a very efficient heat-sink.

I’m hoping to utilise the chimney effect to improve the air-flow over the heat-sink so the bottom and top of the case will be largely open.

22 Oct 2006I
was going to make a custom heat sink from copper plates; similar to the construction of the Zalman flower cooler but, to save myself some time, I will use an aluminium industrial heat-sink that I have in the workshop.

I’m using the same technique that I used on on the SilentPC project to cool the P4-M processor. A copper block acts as a heat shunt, moving heat into a large industrial heat sink which I measured, in situ, to be of about 1K/W.

The copper block has been mated with the heat-sink and flattened and polished to mate with the CPU.

The heat sink (the remaining part of the one used to make my PVR case) is mounted on four adjustable stand-offs screwed through the mother-board’s heat sink mounting bracket holes.

Bench testing gives a CPU temperature of about +36°C over ambient (57°C in my workshop) although the standard heat-sink on the north/south bridge chips gets to a slightly less comfortable 66°C.