Ocean floor as an effective method of cooling equipment

Experts from the National Institute of Informatics of the USA proposed to cool the server equipment by submerging it under water. In general, this team is not original, since Microsoft representatives were the first to load the miniature computing center. But in the USA they are considering the possibility of cooling at the bottom of the ocean not of a small computing center, but of a whole DC. Probably, this is not even the most unusual way of cooling equipment - after all, now mineral oil, water and even liquid helium are used for this purpose.

It was decided to submerge the DC under the water for the simple reason that there is a lot of water in the ocean. And the deeper, so it is colder. Now, with the increase in the number of equipment in the data centers and the continuous increase in its performance, the energy for the cooling systems is increasing. And since the information generated every year is not just a lot, but a lot, then the number of data centers for its storage and processing will grow. Consequently, the cost of energy supply will increase, in particular for cooling systems.

Heat, heat, heat

Now not only the number of data centers and equipment in them is increasing, but also the density of equipment in server racks. Accordingly, heat generation is growing, and it is required to find the most efficient heat dissipation scheme. This is one of the priorities of data center operators.
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If previously the heat generation of computer equipment was very low (remember Commodore, ZX Spectrum), now this figure has increased many times. Without radiators and various heat sinks, the equipment simply cannot function - processors and other server elements are heated very strongly.

Therefore, we need more efficient cooling systems, for this reason, the operators use water, mineral oil, air and all other heat transfer fluids and coolants, trying to find a middle ground in the cooling equipment. But the problem here is common to all systems - an energy supply is needed, and its energy is spent a lot, no matter how efficient the cooling system is. Of course, in some regions you can use freecooling, but even here you can’t do without electricity.

Integration with nature

A small or medium-sized company is forced to use either the power of a third-party data center, or build its own, and the choice of the place of its creation is not so great. These are multinational corporations like Google, Facebook, Amazon can build data centers almost in Lapland. And for ordinary companies, such luxury is unacceptable.

As for corporations, some of them have looked after Iceland as a region where you can easily build a data center with a free cooling system. The external air here is almost always cool and clean, so there is no need for special cooling costs.

The same corporations use the heat removed from the DC to heat nearby objects: houses where staff live, schools and other objects. Here we see a double benefit - heat recovery and minimal energy consumption for the maintenance of the data center cooling system.

But after all, only a few hundred thousand people live in the same Iceland. A data center should provide access to its resources for tens, hundreds or even millions of people living thousands of kilometers away. And the more users there are, the more remote the data center will be from civilization, the more delays can be. To avoid this, DC in some cases, you have to build next to metropolitan areas.

Another way - the one mentioned above. Immersion of servers and entire DCs in the deep of the sea. Here, too, difficulties arise: sea water is a very aggressive environment. With increasing depth, pressure increases. Therefore, the equipment must be very well protected.

But there is a way out

Yes, researchers from the National Institute of Informatics of the USA found light at the end of the tunnel. They have been experimenting with equipment cooling methods for a long time by immersing it under water without sealed enclosures and other related equipment. Their solution is a special hydrophobic coating that allows specially designed servers under water. And in this case there is neither the risk of a short circuit, nor the threat of overheating of the equipment.


The researchers used to test ASRock Mini-ITX

The researchers, led by Michihiro Koibuchi and Kazuki Fujiwara, first tried epoxy based coatings. In this case, they failed because this kind of coating was very uneven. The second experiment was based on the idea of ​​using an aluminum body covered with a waterproof sealant. Again, nothing happened - the water found a loophole.

After a series of failures, the researchers are lucky. They tried a chemical compound called paraxylene, and everything worked out. This substance, in a gaseous state, was used by specialists to process the surface of equipment cases. It turned out that in this case the coating is applied evenly. Para-xylene quickly hardens, forming a fully hydrophobic coating one tenth of a millimeter thick. This was enough for the equipment to work under water without any problems.

Of course, it is not necessary to talk about immersing such equipment to a depth of tens of meters, but for three months the motherboard with para-xylene coating worked in water without problems. After that, the devices began to try to dive into the ocean. The experiment was half successful: some equipment continued to work, some did not, the reason was the influence of various living beings. Somehow, some animals have damaged the waterproof layer.

Now the experiments of experts continue. In addition, the authors of the work are studying the possibility of using the energy of the surf and tides to provide equipment with energy. In this case, we can talk about the almost complete autonomy of the systems. Of course, it’s still far from the practical realization of the idea, but there is a possibility that it will be successful.