Immersion cooling is one of the most interesting concepts and least explored of the hardware. It consists, as its name suggests, in cooling the equipment by submerging it almost completely. In this article, we will review how this is achieved if it is safe and if there are options in the market for it. We started!
Immersion cooling, a very interesting concept
As we say, this is a concept that is overflowing with interest, since seeing how a computer is completely submerged in a liquid as if it were in an aquarium is something that surprises while raising many doubts about whether the computer will be able to survive like this in the long term.
On the other hand, it must be borne in mind that we are not only dealing with something that may be interesting on an aesthetic level. Used liquids can be more than 1000 times better conductors of heat than the air that we currently use in most PCs, in addition to being a "comprehensive" solution, they allow us to focus on all the hot components of the PC, including by, For example, CPU and GPU power systems, and don't limit large cooling capacities to just the GPU.
This can be considered an idea that has potential, a statement that we will analyze throughout the article. But you will also see how important doubts arise about its viability, in addition to that you will appreciate how the precedents that are already on the market are quite limited.
How is it possible that we can submerge a whole PC in the water?
It is clear that the key to immersion cooling is that you do not really use water, but another liquid that does not cause problems and that above all is not a conductor of electricity.
Currently, we find two possible immersion cooling systems: on the one hand, those with two phases, where the heating of the liquid causes it to evaporate to be condensed again later, or those with one phase, where there is no evaporation but rather the Cooling is achieved by moving the liquid with a pump and a radiator.
Two-Phase Liquid Immersion Cooling (2PILC)
In 2PILC type refrigeration, what is desired is an evaporation of the liquid. Therefore, the key is to use liquids with low evaporation points, generally organic compounds and not water or oils. According to Anandtech, the most common are 3M Novec or Fluorinet, which evaporate at temperatures around 59 degrees.
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| 2-phase immersion cooling (source: Gigabyte) |
So that the CPU or GPU reaches that temperature and evaporates the liquid forces its convection, which as we know causes the evaporated gases to rise. When climbing, they will find a cold plate or a water pipe that will cool it, causing it to condense and fall. This is, then, a full-fledged closed circuit.
Note that these systems are the most aesthetically impressive, as we will see the bubbles of the evaporating liquid rise with great speed from where the CPU is.
Single-phase immersion cooling with mineral oils
This is the second possible case, and as we indicated the key is in the forced movement of the liquid by means of a pump and a radiator. Instead of being directly the convection derived from evaporation that moves the air, it will be the pump that achieves the movement towards the radiator, where the heat exchange that cools the water will take place.
In this case, mineral oils are usually used as a liquid, which makes this type of refrigeration more difficult to carry out due to the risks that we will discuss below.
Risks arising from immersion cooling
As much as we use a non-conductive liquid and as "pure" as possible, there are real risks of corrosion problems or other circumstances such as the proliferation of algae in the water. This is something that can happen in liquid cooling if the wrong liquid is used or the correct maintenance is not done, all this despite the fact that it is a closed circuit and in principle isolated. Imagine what can happen on an immersion-cooled PC.
What boxes (or rather aquariums?) Exist for immersion cooling and what yields are obtained
It is time for a reality bath (pun intended) and to see what options can be found in the market, it does not matter if they are currently for sale or not but at least they should have been sold at some point. Here what interests us most are the details of the implementation, how well the equipment is cooled, etc.
First of all, we have all those equipment whose use has been simply at the level of exhibitions or public demonstrations, but without real possibilities of purchase, or simply derived from the modding of the users. An example is in the Gigabyte aquarium, which literally had fish on its top, evidently with the water totally separated from the PC components.
This helps us to clearly see one of the great disadvantages of these systems, which is basically trusted. Few people would be willing to risk their equipment to a fatal outcome, something that, as unlikely as it may be, could always happen if there was a manufacturing defect, for example.
A somewhat more commercial system is the CoolBitts ICEBox, which appeared at the end of 2019, and which is precisely one of the one-phase systems that we were talking about. In this case, all the components are kept submerged, even the power supply, so it should be passive or semi-passive. The only thing that is foreign to the liquid is the I / O panel of the motherboard, to ensure connectivity.
The total power that could cool this cooling is around 750W, which is enough for an immense range of equipment. In fact, the company tested a 32-core Threadripper 2990WX and an NVIDIA RTX 2080 Ti at full load, with a peak consumption of 618W, and the liquid temperature was kept at 30 degrees.
We have talked to you about the problem of trust, and here comes the second: the price. The complete kit of this system is priced at $ 2,450, which as much as the bundle is quite complete and the extraordinarily expensive liquid does not seem like a reasonable price to pay. And returning to confidence, it is curious to see that the manufacturer himself has the box on a tray as if some liquid leak was expected.
We conclude with what has probably been the most interesting implementation of such systems, the der8auer Aqua Exhalare, a project carried out in late 2017 that was supported by the largest German hardware store and one of the most famous overclockers in the world, as well from the sponsorship of manufacturers like Lian Li, so it was really viable to bring it to market.
The Aqua Exhalare followed a two-phase approach, with a 3M Novec liquid, in high-end equipment at the time. That is, an Intel Core i7-7800X and an NVIDIA GeForce GTX 1080. The most interesting thing is that it was sold for € 9,999 at the German retailer.
In fact, in 2018 the project followed with Project Exhalare 2.0, and in 2019 the acclaimed overclocker (and excellent modder!) Made one more version for NVIDIA. Even with its powerful engineering know-how, brand relationships and ambition to get it right, the Aqua Exhalare was never a viable sales option.
Not everything is gaming: use in data centers, from Spain!
At all times we have been relating this concept of immersion cooling with gaming equipment, and even leaving the focus on aesthetics rather than on the cooling capabilities themselves. But one of the most promising projects in this regard is precisely in data centers. There is Submer, a Spanish company that offers a comprehensive immersion cooling solution for data centers.
Their product range is basically a series of "containers" in which all the server hardware is submerged. Its main selling point is the possibility of cooling much more power on the same surface so that the servers will occupy much less as they can be installed closer together.
For example, they estimate that the refrigeration of 200 racks with consumption of 1000kW could be cooled using only 10 units of their refrigeration system, with more or less half the energy cost derived from refrigeration, and therefore significantly reducing the operating costs in addition to using much less space in the rooms.
Conclusions: is immersion cooling achievable?
After seeing the most important details about immersion cooling, it is time to answer the question you are probably asking yourself: is it feasible to make a cooled PC like this?
Technically yes, since there are various cooling liquids on the market that do not conduct electricity and prevent biological problems that could arise from the use of immersion cooling. We also have our own cooling systems, where those with two phases (2PILC) and one phase stand out, depending on whether there is intentional evaporation of the liquid or not.
In any case, it is clear that getting one of these cooling systems is not something excessively easy and viable, hence we hardly see them beyond exhibitions and exhibitions. The market supply is very limited, people do not have confidence in these systems, the prices are not good, etc.
Still, there are those who are trying to bring this concept to data centers, as is the case of the Spanish company Submer. Do you think immersion cooling systems will be more relevant in the future, or will we continue with traditional air and liquid cooling?
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