Thermosyphon tubes or dry heat pipes are an essential component in cooling systems of any kind, and that of course includes PC cooling. In this article we are going to tell you from how they are manufactured to how they work, going of course through the definition of what they are and, in essence, everything you need to know about them.
The PC cooling industry is very broad in terms of models and technologies, but really in terms of techniques there are not many that are used: we have cooling using heat pipes to transfer heat from the IHS of the processor to the fins of the PC. aluminum of the heatsink and then cool them with fans, or we have liquid cooling systems that do the same but using coolant instead of heat pipes (although then in the background, the radiators have a similar functionality).
The idea, in any case, is to be able to transfer the heat generated by an element (in this case the processor or GPU, for example) out of it, to dissipate it later and that the element can continue to work and generate heat without overheating.
What is a thermosyphon tube and how is it manufactured?
As you may already suppose, heat pipes are used in the cooling industry for PCs, and indeed these tubes or caleoducts (conduits through which heat circulates) that we are going to talk about today are nothing but a specific type of heat pipe whose function is to transfer the heat generated by the processor (or other element) and to be able to dissipate it to cool it.
However, thermosyphon tubes are slightly different from heat pipes as we usually know them in the industry, but before getting into the subject, let’s see where they come from, or rather how they are manufactured because the manufacturing process is very important to its operation.
These tubes originate from very large rollers on which very long copper tubes are wound; a special machine unwinds them, straightens them and cuts them, to later be cleaned and filled with a mixture of copper powder. Then, they are placed under a thick heating cover and put in an oven at no less than 980ºC for about eight hours (this process is called sintering and it helps the copper powder stick to the internal walls to give them capillarity) . In the final stages, all the air is sucked out of the resulting copper tube and then approximately half its internal capacity is filled with distilled water .
Indeed, we are talking about a kind of heat pipe, but instead of being filled with air or copper shrapnel, it has distilled water as if it were liquid cooling, with the difference that the thermosiphon tube is totally watertight : they cannot be produce neither leakage nor evaporation of the liquid (unless it breaks, obviously).
The idea behind the thermosyphon tubes is exactly the same as with the heat pipes of conventional heatsinks: they are molded into a heatsink with aluminum fins in order to dissipate the heat from a processor, only in this case it is no longer just copper is the one that transmits heat from one place to another but is also helped by the distilled water inside.
How do these components work?
Eliminating heat is generally quite simple: the thermosyphon tubes absorb the heat generated by the processor and, as they are an excellent heat transmitter, it is distributed throughout your body. From your body, heat is transferred to the aluminum sheets of the heatsink block, which are always being cooled by one or more fans. The flow of operation is essentially the same as on any PC air heatsink.
Internally the process is a bit more complicated, since as we have mentioned before the key to these heat pipes is the distilled water inside, and as you will see they have a great disadvantage and that is that they only work correctly with the heatsink positioned vertically, that is, with the heat pipes rising upwards. Why? By the liquid.
The key is that gravity causes the weight of the liquid to make it be at the bottom of the tubes, that is, as close as possible to the heat source. The heat generated by this (and that area of the copper, which will be hotter than the upper ones, further away from the heat source) make the water evaporate and go up, where it cools (both due to the effect of the fan as by the internal capillarity of the tubes) and returns to its natural liquid state, going down again with a few degrees lower in temperature, cooling everything again and repeating the process.
This constant state of evaporation and liquid is very important, since a pure copper tube does not transport heat as efficiently.
Application of thermosyphon tubes in the PC industry
Believe it or not, both thermosyphon tubes and the technology they carry under their arms have been used for many years. Without going any further, AMD was a pioneer in its day by incorporating steam chamber heatsinks in its graphics cards that use exactly the same principle: copper deposits with distilled water in which the evaporation of this enters the game for the dissipation process of heat.
Even before AMD incorporated it into its graphics under the bombastic name of Vapor Chamber, this technology was already used in passive heatsinks long before. Likewise, there are many active air dissipators that use thermosyphons to increase their performance, and in fact, although in liquid cooling the basis is that the liquid is always in motion, the physics in this technology is exactly the same as that used in this type. of pipelines.