Seven Reasons Why My Oil Is Better Than Your Air

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 Liquid-phase spray or immersion cooling is the safest, cheapest, most reliable way to cool today’s power-dense electronic assemblies. Liquid cooling has a lot of advantages over air cooling, and can do things that air cooling can’t. Here’s your short list of reasons why:

  1. Dielectric cooling oils carry almost 1800 times as much heat as the same volume of air. The rate of energy transfer from a hot item to a cooler one is driven by the difference in temperature between the two. The right cooling oil can absorb 1788 times more energy for the same change in temperature as an equivalent volume of air can. That means that far less oil is needed and that oil can cool tomorrow’s highly dense circuit designs.

  2. Oil acts as an effective thermal buffer, minimizing rapid temperature swings of components. This reduces thermal stress and expansion and contraction, greatly improving reliability of both the components and their connections.

  3. Oil Cooling minimizes corrosion on circuit boards and connections. Closed-loop oil cooling minimizes contamination, reduces the availability of oxidation, and hinders the development of acids on circuits. Here again, this greatly improves the reliability of components and their connections.

  4. Cooling with dielectric oils minimizes failure modes associated with moisture adsorption onto the surface of and in interlaminar spaces of circuit boards. Processed insulating oils are delivered with moisture levels below 30 ppm, and are extremely hygroscopic, drying the moisture from solid materials and circuit boards. (Watch out, though – unprocessed mineral or pharmaceutical oils can have very high moisture content, and actually introduce moisture into the cooling system!)

  5. With oil cooling, pathways for circuit failure through anodic filaments and solder whisker growth are virtually eliminated.

  6. It’s cheaper to pump oil than an equivalent thermal mass of air. In order to cool circuits with power densities of only 0.4 w/cm2, an air velocity of 5 m/s is required, creating high back pressure and requiring powerful fans. With liquid cooling, flow velocities are much lower; pressure drops are minimized and far less energy is required for cooling. Tests show that power required for cooling alone is reduced by up to 98%, which can be as much as 18% of the total energy requirements of a server.

  7. Oil Cooling of servers and processors minimizes the rest of the cooling needed for the entire data center – not having to handle and insulate large volumes of hot air keeps the rest of the data center cooler.

  8. Oil cooling reduces the chance of electrostatic discharge between components and failure modes associated with ESD. Processed dielectric oil is a far better insulator than air, allowing for higher voltages, closer tolerances and greater reliability.

There you have it. You paid for seven reasons and got one extra. For more information on the advantages of liquid cooling of electronic circuits and how to choose the right fluid for your application, contact me at DSI Ventures, Inc., ( , 903-526-7577, or at