Heat Pipes

What is a heat pipe?

To understand the importance and function of thermal management we must first understand one of the most important tools in the arsenal of thermal solutions.

Heat, as a form of energy, can never be destroyed, but it can certainly be moved around. A heat exchanger is a mechanism for moving the heat from one place to another. At the heart of many of these heat exchangers, one can find a heat pipe shuttling the heat from one side to the other. So what is this magical little mechanism, and where did it come from?

Essentially, a heat pipe is a closed tube partially filled with a liquid – usually water. One end is placed into the hot element and the other may be cooled in the open air, by a fan, or by another cooling mechanism. On the hot end of the heat pipe, the heat outside the pipe is boiling the liquid and turning it into vapor. On the cool end of the heat pipe, the heat is being released and the vapor is condensing back into liquid. The liquid then moves back to the hot end through capillary action – which is the same principle that causes water to soak up into a paper towel even if it has to go against gravity.

These pipes were pioneered in the mid-1940s with an eye on possible applications in space, where gravity cannot be counted on to move liquids around and there is no air available forthermal management purposes. Because there are no moving parts and it is a closed system, heat pipes have become the cornerstone of many technical thermal management applications. The principles have remained the same, but the efficiency and vast array of applications for heat pipes in thermal management . Whether you’re in outer space or at home on your computer, the simplicity and elegant efficiency of this device is hard at work to keep you going.