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Mineral Oil Computer Cooling: Components go for a swim


If you want to cool your computer components you basically have two choices: Air cooling or water cooling. For most people air cooling using a heatsink and fan combination is the way to go. Modern copper heatpipe and fan combinations are relatively quiet, efficient and reliable. Water cooling solution are really the elite cooling solution for daily use, where circulating water in a closed system moves heat to a radiator, which may be active or passive (with fans), but is generally much quieter than a multi-fansink solution.

Alternatively, you can fill an aquarium with non-conductive mineral oil and dump all your components into it. That’s right, just completely submerge them, fans and all. Our instincts tell us that this should be a disaster, but since the oil isn’t conductive it’s basically just thicker air as far as your components are concerned.

Cooling electrical equipment in oil is hardly a new concept. Electrical transformers can be cooled in oil, some supercomputers (such as the Tsubame) are oil cooled and of course high performance desktop computers can also be oil cooled.

What are the advantages though? For one thing, immersing your computer components in oil means that all components are cooled, not just the ones with passive or active heatsinks. This helps with increased longevity and stability. Oil cooling does not provide the instant and drastic drop in temperature of water cooling, but the oil has much, much more heat capacity than air or water. Once it reaches a stable operating temperature it stays there. Making it a viable cooling option for long-term computing tasks that take many hours or days. In fact some companies do data centre overhauls that convert existing server blades into oil-cooled versions. It is not however suitable for high temperature overclocking.

So the heat goes into the oil, but what then? A pump circulates the oil through a radiator which then transfers it to the air. In server environments the radiator can be outside the building, but for a desktop unit the radiator can simply go on the back of the tank.

Tank? Yes, most custom builds of oil cooled computers use watertight aquaria. Which means you can do lots of interesting things with lighting and aesthetics.

One very important issue to note is that you can’t submerge DVD drives or spinning magnetic disks. These need to be in air to work. So they need isolated drive cages is you need to use them. SSDs, being electronic, are unaffected. So they can go in the tank with everything else.

Also take note that any rubber based insulation will dissolve in the oil, so make sure nothing important relies on a rubber component. Especially wire insulation.

So, to recap, these are the basic components that go into oil-cooling a PC:

  • A watertight container to mount components.
  • Specialist non-conductive mineral oil.
  • A pump to circulate the oil.
  • A radiator to dissipate the heat
  • Some fish to swim around the tank (don’t actually do this, the fish will die).

The internet is filled with kit components and how-to guides for oil cooling projects. Oil cooling a PC is a completely different experience and can make for both a great conversation piece and a functional system.

Would you try oil cooling? Have you ever built a system like this? We’d love to read your comments and see the pictures.