Conventional liquid cooling involves heat from the components of the PC being dissipated into water via a metal plate, so no water has direct contact with the components, and then being cooled in radiators to dramatically decrease temperatures of the hardware in use. However, some people cool their systems in a unique way…
Mineral oil behaves different to water that is usually used to cool PC’s. Although it looks like water, the oil does not have the free electrons necessary to conduct electricity, therefore it does not fry computer components. It is possible to completely submerge a computer system into a tank full of mineral oil, heat is transferred to the oil five times faster than air and can be dissipated through radiators just the same as water can.
The oil does not corrode any components of the PC, although parts such as the hard drive disk (HDD) cannot be submerged in the oil at all, as it is viscous and would stop the disc from spinning at its full speed and the read heads would be restricted from free motion. However, solid state drives will work perfectly fine in the oil as they contain no moving parts.
Although the oil is quite viscous, it’s not thick enough to stop fans moving at their full capacity, so some cool effects can be witnessed when fans are in motion inside the oil.
Creating a mineral oil-cooled system is a fun project to do, and it certainly is a cool alternative to standard water cooling methods which most high spec systems utilize nowadays.
Overall there are cheaper methods of liquid cooling, there are more practical ways of keeping system temps low, and there are lots of less time consuming ways of cooling your PC. But there is nothing cooler than being able to tell people you keep your PC inside of a fish tank.