Originally Posted by tuchan
That just might work but will the heat pipes transfer the cold down towards the cpu or do they only run in one direction.......
I just re-read through and found a problem... Cold isn't transfered. Technically, cold doesn't exist. Cold by definition is the abcense of heat and is relative to something else (in this case, if something "feels cold" that means it's temperature is lower than your body temperature). So the "cold" wouldn't be transfered down to the CPU, the heat is transfered to the coldplate. So the heat is still moving in the same direction, and because of this, the only problem with the heatpipes is the temperature difference, whether they'll work in subzero conditions or not.
The easiest way to test this is to stick a PC in a deep-freeze or outside when it's below 0C out. If the CPU temperature continues to drop to below freezing (or close to whatever temperature it is outside) than the heatpipe cooler will work with the peltiers.
However, if whatever liquid that is in the heatpipes does freeze, than the heatpipes will no longer efficiently transfer the heat to the fins, and the fins will just get colder and colder while the CPU heats up.