don't heatpipes work on gravity?

[ElFenix]

if so, isn't a heatpipe essentially worthless in a tower, where the coolant will be sitting in the lower extension tubes of the heat pipe, rather than boiling off over the CPU, condensing in the radiator, and then falling back down to the CPU?

 

[GalvanizedYankee]

They work in a gravity free environment. Internal wicking will cause capillary action to draw the condensed fluid back to the heat source. Some work better than others.

This has been discussed several times in the C&C Forum over the last few months


...Galvanized

 

[ElFenix]

Originally posted by: GalvanizedYankee
They work in a gravity free environment. Internal wicking will cause capillary action to draw the condensed fluid back to the heat source. Some work better than others.

This has been discussed several times in the C&C Forum over the last few months


...Galvanized

interesting. i wasn't aware that capillary action had much effect in a large tube.

 

[MagnusTheBrewer]

Perhaps conduction might be more accurate.

 

[GalvanizedYankee]

Howard will see this thread and really work the subject over 😉

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

Consider...Lappies use heat pipe tech for cooling. They get used in most any position.


...Galvanized

 

[Rock Hydra]

oop...n/m

 

[Howard]

Originally posted by: GalvanizedYankee
Howard will see this thread and really work the subject over 😉

Hey! I resemble that remark. 😉

ElFenix, you're thinking about thermal syphons, not heat pipes.

 

[ElFenix]

Originally posted by: GalvanizedYankee
Howard will see this thread and really work the subject over 😉

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

Consider...Lappies use heat pipe tech for cooling. They get used in most any position.


...Galvanized

interesting

 

[Blain]

Thermalright has recommendations & ratings for heatpipe orientation.
I'd imagine it's got more to do with convection than anything.

 

[corkyg]

Conduction is the movement of heat through a substance by the collision of molecules. Two objects must be touching for this transfer to occur. On the boundary of a hot object the faster-moving molecules collide with the slower-moving molecules on the boundary of the cooler object. In this way, the slower-moving molecules gain energy and move faster. They strike other molecule inside the cooler object. Heat energy is spread throughout the object. Conduction is a good way to spread heat energy in solids.

In liquids and gases, convection is usually more efficient. Convection is the spreading of heat energy by movements of heated liquids or gases, such as water and air. To understand how this works, picture a fireplace. As the fire heats the air around it, the warm air expands and takes up more space. The warm air is less dense and floats above the more dense cool air. The warm air rises up the chimney, taking the smoke and ashes with it. Cool air from the room flows into the fire from all sides to take the place of the rising warm air. A continuous circulation pattern of hot and cold air is set up in the room. This example of convection demonstrates how heat energy is moved around by the circulation of air.

In that sense, a heat pipe is a solid conductor and heat moves through it. In that scenario it could be both conduction and convection. However, convection is usually more associated with free air.

 

[zephyrprime]

Heatpipes work primarily based on wicking and that's why poorly oriented heatpipes still work.

Heatpipes were originally invented for the space program to cool things in space where there is no air. The radiators in space rely entirely on black body radiation to cool down.

However, convection does play a part while on earth and I've seen a site that test a heatpipe in different orientations and there was a few degrees difference between the good and not so good orientation.