Everything Else

I have a question for the HPC computing people on Nekochan.

Does anyone have an idea on the price of 3M Novec dielectric liquid fluid? I'm interested in the idea of doing a liquid immersion cooling experiment on a PC and would like to get a ballpark idea of the cost for the fluid before I call any 3M sales guys and try to buy enough to fill a small fishtank.

This was inspired by looking an article on ITWORLD Intel and SGI test full-immersion cooling for servers and from looking at the work done by http://www.iceotope.com/

I'm less worried about the computer and the cost and more worried about a leak in the tank.

Fire extinguishers using the same chemical seem to be priced in the range of $50-100 / kg.
I do not know if it is less expensive in bulk, it doesn't seem to be a chemical that is readily available in bottles or drums.

For a PC in a fishtank I have seen mineral oil used successfully for a fraction of the cost..

From TFA: "Novec can help CPUs operate at a consistent temperature, which Patterson said can help reduce electrical leakage on chips. " Huh?

Here are a few video clips from Youtube / Vimeo that show the OBI Open Bath Immersion cooling process. It's pretty amazing to see the Novec 7000 fluid boiling and circulating over the motherboards at low temperatures like 34°C. The process works without any aluminium heatsinks or fans mounted on the CPUs.

Immersion Cooling with 3M Novec Engineering Fluids
https://www.youtube.com/watch?v=a6ErbZtpL88

Boiling Liquid Submersion Cooling Computer
https://www.youtube.com/watch?v=Z_X_hgtlJpA

Immersions-Cooled Server Cluster
https://www.youtube.com/watch?v=NymeDU96pac

Server Demo Part I
https://www.youtube.com/watch?v=nppkJbcKUnw

Novec 7000 Based HFE cooling to improve efficiency of servers
http://vimeo.com/37127378

Ah, I thought you meant Novec 1230, which is entirely different (it is a perfluoroketone).
the HFE Novec 7000 is available in 1 gal bottles for about $300.

It might be interesting to look at cooling an imac this way, using an external heat pump

You could try using mineral oil, should be significantly cheaper.

I think the posters discussing mineral oil are fixating on the "liquid cooling" bit, and not the applications that the OP linked to. The systems he described are using two-phase heat transfer, where the medium must boil to remove a sufficient amount of heat. Compared to two-phase cooling, a purely liquid phase system must have either a greater liquid volume or faster pumping speed or both ( paribus specific heat). For applications where there is a very concentrated source of heat, such as a chip with a high TDP, some kind of heat sinking may also be required. This requirement does not exist with the Intel/SGI type of two-phase cooling the OP mentioned. Fluorinert FC-72 should work as well.

There are also problems caused by a boiling fluid, as the expansion can disturb components on circuit boards. The whole assembly should be conformally coated to prevent bubbles forming underneath packages, although epoxy underfill could also work (albeit more labor intensive).

Yeah, I missed that bit until I actually watched some of the videos he posted

But if you just want a gee-whiz-lookatme! submerged computer (and a big greasy mess....) mineral oil is not a bad way to go.

Hi robespierre.

robespierre wrote: Ah, I thought you meant Novec 1230, which is entirely different (it is a perfluoroketone). the HFE Novec 7000 is available in 1 gal bottles for about $300.

Thanks for your responses to my questions and the pricing info for a bottle of Novec 7000 fluid. It's pretty amazing to think a 55 gallon barrel of the stuff would cost ~$17,000!

The Novec fluid has really interesting physical properties. When a circuit board is extracted from the Novec liquid it comes out clean and dry which would make it easier to service a computer module compared to cleaning up a component saturated with mineral oil. The open bath immersion cooling system should become more common in the HPC market when higher density systems are deployed with even greater cooling requirements.

I noticed it's possible to get the occasional bottle of the HFE Novec 7000, 7100, and 7200 liquids on eBay so I might look at that route for sourcing supplies for my experiment.

Thanks again,
Andrew

Andrew:
I just noticed that you are in Canada. You should call MG Chemicals and ask if they can provide you with samples.
http://www.mgchemicals.com/products/cleaners/3m-fluids/

Oh man, always good to see someone else crazy enough to dunk their most valuable electronics in a fishtank! I'm also messing with Novec in an immersion cooling project now - I'm using Novec 649 to cool bitcoin miners, as its boiling point of 49°C is right at a normal operating temperature for a lot of ASICs. So far the results are great, although I would definitely look at using a more specialized enclosure - unlike mineral oil you won't get any benefit from having a lot of idle fluid/thermal mass, and it will run up the cost of your project very quickly. The tank I'm using is custom designed to hold as many ASIC boards as I can fit into it with just enough space between them to allow for bubbles to rise easily, and the recondensed fluid is piped to the bottom of the tank and reintroduced through holes between the boards. This minimizes the amount of fluid needed and keeps it constantly circulating without a pump.

thebulbguy wrote: The tank I'm using is custom designed to hold as many ASIC boards as I can fit into it with just enough space between them to allow for bubbles to rise easily, and the recondensed fluid is piped to the bottom of the tank and reintroduced through holes between the boards. This minimizes the amount of fluid needed and keeps it constantly circulating without a pump.

hamei wrote:

Not exactly high tech, but they worked better than the windows-down 2/60 alternative....



But if you're gonna do gotta-be-movin'-to-stay-cool, you might as well lose the radiator too:

Did you get anywhere with this?
I was thinking about some of the new manycore processors and how they really could use a denser cooling solution. for fpgas, too.
I stumbled on this presentation that gives a lot of useful details including a blueprint for a whole tank system (near the end):
http://youtu.be/ivVoANqFBuY
One detail I hadn't seen before is that they use a special heat transfer material on the outside of the metal chip case, made of sintered copper. since it's sintered, it has a much larger surface area and lower thermal resistance, similar to the reason ultracaps have high capacitance. what I don't know is if they apply it chemically, as a paste or what.

Hi. I've done a few small tests with fluorocarbons but haven't gotten to the point of doing open bath immersion due to the cost of the fluid.

The surface enhancement coating is called a BEC "boiling enhancement coating" that is applied using a spraying process. Phil Tuma from 3M has prepared a few youtube videos that show how it is applied to a CPU's heatsink.

After a heatsink has the BEC compound applied it is bonded to the CPU using a Multicore Solder Vaporette Heater. A Vaporette heater is an SMD soldering device that works by immersing CPUs and heatsinks in a hot vapour of Flourinert FC-40 which offers a precision temperature controlled CPU soldering environment.

Spray Coating of Pin Fin Boilers for Sandybridge CPUs
https://www.youtube.com/watch?v=fMl3cnbsbUg

CPU Soldering
https://www.youtube.com/watch?v=kUVtvfsaZbY

i watched more of his slide presentations...
it's hugely interesting, but there are a lot of problems with routing cables and plastic components leaching into the dielectric fluid. PVC insulation seems to be a particular problem, so you really want to custom engineer the entire device using materials that aren't attacked by the fluid. Teflon insulated wires instead of PVC, and so forth (you may have noticed that the cables in his test computer are not standard ethernet Cat5). At least the epoxy chip underfill is compatible.

robespierre wrote: i watched more of his slide presentations....

Aren't the radar systems in military aircraft liquid-cooled ? Seems like there would be a lot of high-dollar experience there to be utilized.

Yes, many are. There are also a huge number of power converters for trains that use it, but they tend to be hermetically sealed.
That solves a lot of problems, but at a high cost, since multi-pin hermetic connectors can cost several hundred dollars... per connector.