Evaporative immersion


I work as a Thermal Application Engineer in 3M’s Electronic Markets Materials Division.  For more than 50 years, my group has made fluorochemical heat transfer fluids that have been used for immersion cooling of high value electronics.  Some are familiar with the various Fluorinert™-cooled Cray supercomputers but our fluids are also used in tens of thousands of immersion cooled traction inverters and a variety of military platforms.  

Evaporative immersion is arguably one of the most efficient ways to implement fluids like ours for cooling electronics.  Heat sources on a PCB immersed in the fluid cause that fluid to boil.  This captures all heat and allows it to be transferred efficiently to air or water via a secondary condenser.  Historically, immersion systems of this type have used sealed pressure vessels with hermetic electrical connections and are evacuated and filled much like refrigeration systems.  Because it can be costly to create such an enclosure for computational electronics with a lot of IO, Engineers often dismiss the idea of immersion in the context of commodity datacenter equipment.  The concept we are promoting (see attached) eliminates these complexities.  Other advantages are summarized below.

- All server level and most rack level cooling hardware are eliminated
     – reduced environmental impact (landfill)
     – simplified server/rack design 
     – reduced cooling equipment cost 
     – no moving parts to fail or leak

- Essentially no thermal limit on server power density 
     – 4 kW/liter (4 MW/m3) has been demonstrated (>100X typical air cooled and >25X typical supercomputer) 
    –  possibility for reductions in raw material usage (PCB, etc) 

- Intrinsic fire protection

We are demonstrating this concept with real computing hardware but because we are using off-the-shelf air cooled components, the power density merits of this technology cannot be realized and the demonstration will lack luster.

We seek partners with challenging-to-cool hardware and an interest in exploring this technology.  We believe it could be a transformative technology enabling the next-generation power density goals of the HPC industry.

Readers can learn more at:


or write to me for an Overview Presentation.  Thank you and Best Regards,

Phil E. Tuma
3M Electronics Markets
Materials Division