Heat Pipes

Heat Pipes are Copper Tubes filled with phase change liquid. Extremely effective high thermal conductivity: 5000 W/mK and higher.

Heat pipes are used to transport heat over a distance with very low thermal resistance. This is very helpful when small or distant heat sources need to be dissipated over a larger area or moved to a remote heat exchanger. Heat pipes are a transport mechanism to move heat from the hot source to an area where the heat can be dissipated. Heat pipes do not actually dissipate the heat and are therefore incorporated into many different types of heat sinks as helpers.

A heat pipe is a copper tube with an internal wick structure that is sealed on both ends with a small amount of water inside. As heat is applied to the pipe, the water will boil and turn to a gas, which then travels to the colder section of the heat pipe where it condenses back to a liquid. It is the evaporation and condensing of the water that forms a pumping action to move the water (and thus the heat) along the pipe.Heat pipes are a Fluid Phase Change application, often referred to as “re-circulating,” because they use a closed loop to transfer heat quickly through evaporation and condensation within the heat pipe.

Heat pipes have proven to be robust and reliable over many years in these types of applications.  Many thermal systems benefit from the addition of heat pipes, especially when heat sources are dense and/or remote to the final heat exchanger. Computer applications, such as processors, graphics cards and other chip-sets, have high thermally dissipated power in a small area. Fan heat sink combinations used in these applications can offer high-performance dissipation to the ambient, but much of the battle is to bring the heat to the heat exchanger with as little temperature change as possible. Heat pipes excel at this and can transport large heat loads from small areas with very little temperature difference.