Heatpipe orrientation?

[rumpleforeskin]

Fitted a Hyper 212+ to my pc a few days back and have it so that the heat pipes are vertical (so that the hot air can easly be exhausted via the rear case fan)

Anyways out of curiosity when touching the heatsink i noticed the bottom 4 heatpipes where very cool compared to the top heatpipes which were quite hot. Possibly the liquid inside the pipes was pooling in the bottom of the pipes?

In the interest of unscientific benchmarking i rotated my cooler through 90' so now it exhausts upwards via the PSU, and the load temp is 2'c lower and all the pipes get evenly warm

But if i lay the case on its side so that the pipes all point up its does not matter which orientation i have the cooler but it runs 3'c cooler still (thats 5'c difference from when i started)

interesting yes?
is this a peculiarity of the hyper212+ or something which affects all heatpipe coolers?
There was nothing in the instructions regarding best orientation to gravity for optimal performance, and heatsink benchmarks never seem to comment on it. But it does seem the heatpipes work best when assisted by gravity instead of fighting it.

 

[Elixer]

I thought most, if not all heatpipes use a "wick" technology, so gravity plays very little to no role at all... Hmmm

 

[aigomorla]

I thought most, if not all heatpipes use a "wick" technology, so gravity plays very little to no role at all... Hmmm

correct.

we went to capilary / wick on pipes.

 

[gorobei]

this is pretty typical, most sites that test both orientations find that pipes running horizontally across the heatspreader does better by a few degrees. Wicks rely on surface tension which is going to be slower/less effective than gravity.

 

[Rubycon]

Heat pipe orientation most definitely does matter. Problem is it's not recognized because yes the wicking allows multiple directional use HOWEVER it does have a penalty in capacity!

If your cooler is running near capacity in an optimal orientation and you turn it and capacity is now reduced where the load is too great your temperatures will definitely increase. I observed this with the three pipe Tuniq Tower and a very warm Kentsfield QX6700 CPU at 3.6GHz/1.450 Volts.

When the CPU was running stock temperatures changed little with orientation!

As long as you have sufficient heatpipe capacity you can have it mounted as you see fit. Coolers such as the six pipe Megahalems, VX, TRUE, etc. have sufficient capacity so this is usually not an issue.