How does mineral oil cooling work? What is the overall process?
In the simplest form, an electronic system such as a server can simply be submerged in an open bath of suitable liquid like mineral oil or Novec -- 3M's proprietary liquid coolant. One example is the 250 gallon rack immersion system from Green Revolution Cooling. The electronic system is powered and operated normally. Since the cooling liquid is inert and nonconductive, the power and electronic signals are unaffected. During normal operation, liquid absorbs the heat produced by the electronic devices like processors and memory.
The second and more complicated issue for mineral oil cooling is dealing with the heat absorbed into the liquid, and the solution depends on how warm the liquid becomes. For a single server in a simple open mineral oil bath, a basic pump may be enough to just circulate the fluid through some heat sink piping to dissipate any heat to the open air. Other systems may circulate the heated cooling fluid to some other form of heat exchanger system.
Companies like Iceotope, however, use a water-based heat exchanger system to pull heat from a blade server encased in a quantity of Novec. Water at about 45 degrees Celsius is introduced at the bottom of the blade and passed through a series of pipes within the passive Novec bath (the actual cooling fluid is not actively pumped or circulated). The water absorbs some heat from the Novec fluid and leaves the blade at a slightly higher temperature; usually less than 50 degrees C.
This was first published in April 2013