Martin looks at total liquid submersion of a computer for effective cooling with no moving parts

In the lab we are always experimenting and looking for ways to improve our technologies and bring better, more versatile systems to our customers. Just recently we wrote a editorial article for an industry trade publication regarding this experiment, and it seemed like an interesting topic for this month’s Martin’s Corner as well.

The idea of cooling computers through liquid submersion, has been around for about 50 years… but it has been generally reserved for the more exotic supercomputers and never really caught with mainstream users. Perhaps it’s because we in the technology world are all wired at an almost primal level to believe that: “Liquid + Computers = BAD”. In any case, the concept is slowly catching on, particularly with some in the video gaming community who are using mineral oils as a non-conductive liquid to totally submerge a computer in. The mineral oil idea is interesting… but I can’t imagine the unholy mess that comes about when it’s time to upgrade or make a change, plus, mineral oil isn’t exactly the best for heat exchange.

We decided to take a different approach for an experiment, and instead boiled the computer alive!

3M™ produces a safe, non-toxic, environmentally friendly liquid that looks just like water… but it is actually a non-conductive chemical with a very low boiling point of only 34C (93.2F), that easily condenses from gas back to liquid. The chemical is known under the trade name “Novec™”, and leaves behind no trace once the board is removed, because the liquid evaporates on the warm surface so quickly. In the end, what we ended up with was a very ugly, tape covered, “proof-of-concept contraption” that was quite a novelty to watch in operation.

Imagine a computer completely submerged in what appears to be water, no heat sinks, no fans, running at full blast during a burn-in, boiling liquid over the processor and keeping perfectly cool. The vapor from the bubbles rise up and are easily condensed back to liquid via some type of heat exchange such as a basic water cooled radiator, or in our case we used a solid-state thermoelectric cooler (Peltier).

The i3 processor we tested, in normal air becomes too hot to touch within about 5-10 seconds. When submerged in the liquid, it happily bubbled away at 100% load, and maintained a core temperature of 55C or less, and a surface temperature of 34C. Through convection, the fluid moves around, rising and falling with the temperature changes, ultimately very effectively cooling the entire system.

This technology holds some very interesting potential, such as:

    • Possibly allowing the use of larger processors in closed/sealed computer systems. For our oil/gas clients, this could mean more processing power that previously possible in explosion proof housings.
    • Providing pressure resistance for deep underwater computer systems. Liquids don’t compress, so a sealed computer housing filled with liquid could withstand some very deep underwater operations.
    • Shock absorption, liquid slows down motion, there is potential to increase shock and vibration resistance using a liquid filled container
    • Much greater computing density, and amazing energy savings for server class systems

In the end, this was just an interesting first experiment that we thought our readers might like to catch a glimpse of. At these earliest stages, it would seem that for the vast majority of our customers this will probably be nothing more than a novelty that is interesting to watch.

However for a few of highly specialized applications out there, this cooling technique could have game-changing potential. If your company has a very specialized need for this type of cooling, be sure to let us know. We always welcome customers that are interested to participate in testing and developing new technologies.

I can be contacted at, martinscorner@corvalent.com.

We always love to hear feedback from our readers!

Click Below: Video of our ugly, tape covered, submerged liquid cooling, proof-of-concept contraption
http://www.youtube.com/watch?v=Z_X_hgtlJpA