So wouldn't it work best if the fluid-filled heatpipes were verticle? (so the condensed fluid flowed down to the CPU)

[soccerballtux]

However, since when did anyone have their computer on their side.

So the way I understand it, the fluid vaporizes from the heat; vapor condenses on heatpipes and flows back down the sides of the heatpipes towards the CPU. But if your case is vertical and the fan is horizontal, then all the fluid ends up on the bottommost pipes, not touching the CPU at all.

?

 

[sutahz]

Read up:
http://www.cheresources.com/htpipes.shtml

This isnt as good of an explanation of heatpipes as I read before, but it does contain a lot of the same information (AND PICS!!!, ie i think they ripped off a lot of the info). what it doesn't contain (this link) is what makes a heatpipe more efficient.
If I recall correctly, heatpipes work best when they have a big diameter and are straight.
By reading this article you'll see how your concept of a heatpipe is wrong, but thats just ok, you didn't know, and never cared enough to research it yourself.

 

[soccerballtux]

Well, I had already researched it, but all the article said the heatpipe was was a pipe of copper/aluminum/whatever filled about a quarter full of liquid; and since the cpu was "under" this pipe, and the pipes pointed up, the fluid evaporated inside the pipe; and this action helped it trasfer heat towards the end of the pipe effectively, at which point it condensed, gave off its heat, and fell back down (thanks to gravity) towards the CPU again and repeated the process. Similar to what would happen if you were boiling water and your pot were very, very tall.

Thanks for the link though that's everything I could have wanted. Had no idea about the porous wick.

 

[Jiggz]

Originally posted by: soccerballtux
However, since when did anyone have their computer on their side.

So the way I understand it, the fluid vaporizes from the heat; vapor condenses on heatpipes and flows back down the sides of the heatpipes towards the CPU. But if your case is vertical and the fan is horizontal, then all the fluid ends up on the bottommost pipes, not touching the CPU at all.

?

You do have a point on your question especially if the hsf is oriented sideways as you've mentioned on tower type case or where the mobo is vertically oriented. However, the part you are missing is the wick or the absorbent inside the pipes which ensure the liquified vapors are returned back to the heat source regardless of orientation, albeit the heat pipe is still more efficient when vertically oriented.

 

[CTho9305]

I'd think as long as capillary action (in the wick) pulls enough of the liquid back to the hot side, you wouldn't benefit more from a different orientation. Of course, without a wick, the right orientation would probably be extremely important.