Do heat-pipes contain liquid inside?

A

aviat72

Limp Gawd
Joined
Dec 19, 2010
Messages
508
I have a very basic question.

A lot of after market air coolers have heat pipes which go up to a radiator like structure with a fan. The Hyper 212 is a great example.

I was reading about the thermal solution in the Shuttle bare-bone PC and there ICE-2 cooling. They say that the heat pipe is filled with distilled water. Is this true of all these type of air-coolers?

I have been reluctant to try out liquid cooling so far because I am worried about leaks but if the heat-pipe coolers are also filled with water this changes the game...

http://global.shuttle.com/unique/page?pageName=cooling

Integrated Cooling Engine 2 (ICE 2)

Like its predecessor Integrated Cooling Engine 2 (ICE 2) uses convection cooling to dissipate heat away from and around the CPU. With all the same basic concepts and designs, the new improved version ICE 2 includes, copper tubes coated in nickel enhances tube hardness and rust-proof protection are filled with distilled water, effectively channels heat away, providing high efficiency processor and chassis cooling. Allows XPC to remain under a stable, cool, concise and silent condition.

unique-32.jpg
 
http://en.wikipedia.org/wiki/Heat_pipe


A heat pipe or heat pin is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces.
At the hot interface within a heat pipe, which is typically at a very low pressure, a liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface. The vapor condenses back into a liquid at the cold interface, releasing the latent heat. The liquid then returns to the hot interface through either capillary action or gravity action where it evaporates once more and repeats the cycle. In addition, the internal pressure of the heat pipe can be set or adjusted to facilitate the phase change depending on the demands of the working conditions of the thermally managed system.

A typical heat pipe consists of a sealed pipe or tube made of a material with high thermal conductivity such as copper or aluminium at both hot and cold ends. A vacuum pump is used to remove all air from the empty heat pipe, and then the pipe is filled with a fraction of a percent by volume of working fluid (or coolant) chosen to match the operating temperature. Examples of such fluids include water, ethanol, acetone, sodium, or mercury. Due to the partial vacuum that is near or below the vapor pressure of the fluid, some of the fluid will be in the liquid phase and some will be in the gas phase. The use of a vacuum eliminates the need for the working gas to diffuse through any other gas and so the bulk transfer of the vapor to the cold end of the heat pipe is at the speed of the moving molecules. In this sense, the only practical limit to the rate of heat transfer is the speed with which the gas can be condensed to a liquid at the cold end.[1]
 
Heatpipes usually contain some type of liquid, but usually not distilled water, or water in general.

It usually uses a liquid that would evaporate at a relatively low temperature. The gas then travels up the heatpipe, where it condenses and cools, then travels back to the heat source to repeat the cycle. This method of convection is much more efficient and quicker than just convection by distilled water.
 
you dont need to worry about a heat pipe leaking. unless you attack it with a hatchet
 
Water cooling leaks because you can get leaks or defects in the tubes and seals, since they aren't a full solid hard surface. Heatpipes are presoldered, so nothing is going to leak unless you take a sledgehammer to the heatsink, lol.
 
Tsumi said:
Heatpipes usually contain some type of liquid, but usually not distilled water, or water in general.

It usually uses a liquid that would evaporate at a relatively low temperature. The gas then travels up the heatpipe, where it condenses and cools, then travels back to the heat source to repeat the cycle. This method of convection is much more efficient and quicker than just convection by distilled water.
Click to expand...

the boiling point of water raises and lowers in accordance with pressure. at atmospheric pressure water boils at 212f/100c, raise that 18psi and it will boil at closer to 260f. however if you lower it to 28-29inHG it will boil at room temperature. thus if the heat pipes contained distilled water under vacuum, they can be engineered to be at the point of phase change around standard cpu operating temperatures. furthermore distilled water is cheap, easy to handle and no toxic, all beneficial from a manufacturing point of view
 
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