Liquid nitrogen Cooling

[triatium]

Hey there all.

Saw the 5ghz project, and the recent 8ghz breakthrough, both using liquid nitrogen.

The problem for liquid nitrogen that it evaporates immediately means its logistically unsustainable unless a closed circulatory system is implemented, but (A) what would happen if you kept your entire board with peripheries (including HDD'd but not DVD-RW's etc) in liquid nitrogen the entire time? Would the structural integrity be compromised with the thermal contractions and expansions from prolonged exposure vs heat of use?, and (B) can one safely create a closed system with all necessary wiring coming from within the system to the outside, without coolant leak around the seals for the wiring? What type of sealant would one use to stop ssuch event?

I must confess that I do not know much about liquid nitrogen, but it seems to be the best in terms of keeping one's rig ultimately chilly.

 

[triatium]

Thanks for the heads up. A friend of mine mentioned that liquid nitro would make theboard brittle. How do they mod a motherboard? thought once those mobos came out, one cant really make physical changes to any degree really. any ideas how its done?

 

[sarsoft]

One more thing to add Liquid Nitrogen is expensive. Runing it at continueal supply of liquid nitrogen you better be rich.

Does anyone know the link on Youtube KIngpIn (Priceless) clip?

 

[apt403]

I bet if you sumbmegered the HDD in liquid nitro it would just cease to function, i mean, the thing needs to spin, and if everything is frozen no spinning will be done. And the metal would get really brittle, if it did work the platters might just shatter when the drive spun up.

 

[sarsoft]

True indeed.


Here is the clip.

http://youtube.com/watch?v=Ue1CYNtUYec

 

[tool_462]

You will notice K|ngp|n refers to "suicide run" because he had the copper pot on the CPU/GPUs for such a long time. Usually they only get in a certain amount of time before they have to let the board thaw out.

The only way to have sub zero temps for 24/7 use it to use phase change or TEC cooling. And to have sub zero temps with a TEC you have to have a monster TEC and probably cool it using phase or cascade cooling.

 

[apt403]

If you had like the greatest phase change system on earth you might be able to use liquid nitro as a long term cooling solution, since you could use the phase system to keep an enclosed tube of nitrogen in its liquid state. Butane might be a great cooling sultion as well, all you need to turn it into a liquid is pressure, and it has a similar melting point as liquid nitro, so you could sell enclosed, pressurized colums of butane to use with a phase change cooler, it could almost entirly replace liquid nitro in the realm of oc'ers. The only problem would be if you forgot to turn the phase change system on or something, and the butane heated up....and exploded....

 

[clue69less]

Chances are the liquid nitrogen will conduct electricity. Don't know for sure.

Nope. The electrical conductivity of LN2 is low. N2 is pretty inert because the two nitrogen atoms in an N2 molecule are held together with a very strong triple bond. This has been discussed on Slashdot and you can find data in the literature if you want actual conductivities for different preps. This reference lists LN2 as an insulator.

 

[nvalhalla]

A problem I don't often hear addressed in these discussions is safty. You could use N2 to cool a CPU for regular use (expensive, but could be done), but you would need a room with VERY good ventilation. Remember, N2 cools the CPU by evaporating (that's why the butane/TEP cooled N2 idea posted earlier wouldn't work) and that N2 will slowly fill a room. Without good airflow, you will suffocate. Plus, N2 is pretty dangerous stuff to handling. Spills can be disfiguring.

 

[apt403]

(that's why the butane/TEP cooled N2 idea posted earlier wouldn't work)

Note the "enclosed tube" part, butane needs to be in a pressurized enviroment to stay a liquid if its at room temp.

 

[nvalhalla]

(that's why the butane/TEP cooled N2 idea posted earlier wouldn't work)

Note the "enclosed tube" part, butane needs to be in a pressurized enviroment to stay a liquid if its at room temp.


You seem to be missing the point. A gas under pressure will cool the matter around it when it evaporates. That's what makes liquid nitrogen cold. The liquid needs to absorb energy(heat) from the matter around it to expand(boil) to it's gas state. That won't happen in a enclosed tube. If it were that simple, Intel would have implemented it for the P4 years ago.

 

[apt403]

Hmm, then maybe somekind of enclosed loop with somekind of motor...Oh, wait, thats what a phase change cooling system is! Ok, so my idea is completly flawed, i knew it seemed a little too simple...

 

[triatium]

Hey there

Don't feel bad at all bruski! I envisioned a mobo + gpu in a case similar to those transport canisters that they haul liquid nitro around in, with the pressure and vent valves having their own dedicated ventilation ducting.

Sounds too simple eh?

 

[tool_462]

If the butane was enclose in a pressurized loop, you would have to use a high pressure radiator that allows expanding and contracting to dissipate the heat. I think cascade units are the way to go for something like this.

 

[rubix_1011]

The only way to have sub zero temps for 24/7 use it to use phase change or TEC cooling. And to have sub zero temps with a TEC you have to have a monster TEC and probably cool it using phase or cascade cooling.

This is probably the best idea if you want extremely cold sinks for your CPU. They are commercially made for retail sales, provide good reliability and are easy/'cheap' to use compared to N2. Save yourself the trouble of N2 and just go with a TEC setup. At least that way, you don't always have to find a source of N2 just to boot up your PC.

 

[tool_462]

I know a guy over at xtremesystems uses a double cascade and three potted peltiers stacked together for a rediculous setup. I will try to pull up the old thread, I think he had temps around -65C.

 

[rubix_1011]

I know a guy over at xtremesystems uses a double cascade and three potted peltiers stacked together for a rediculous setup. I will try to pull up the old thread, I think he had temps around -65C.

I would think that would be extreme enough for any day-to-day user. Unless you are going for world records, TECs will be more than sufficient for anyone wanting super overclocks.

 

[tool_462]

I don't recall the CPU he had, might have been a D840 (badass CPU at the time) and he had 1.725vcore 8O Wish I could run that comfortably 24/7.

 

[clue69less]

A problem I don't often hear addressed in these discussions is safty.

If you use LN2 in industrial apps, the safety regs are well publicized.

You could use N2 to cool a CPU for regular use (expensive, but could be done), but you would need a room with VERY good ventilation.

Just leave the door open in your computer room and you should be fine. One thing to remember is that air is over 75% nitrogen to begin with. If you live in a really airtight home, I'd consider bringing in some outside air. Our house has a duct in the basement that brings in outside air for combustion in the heaters and for exchange.

Plus, N2 is pretty dangerous stuff to handling. Spills can be disfiguring.

I've used it for years without any incidents or close calls. You just follow the known procedures and you're good to go. In order for a spill to be truly disfiguring, you'd need a sizeable volume. Lab rats throw liter to gallon quantities around for fun all the time. Now if you're talking T2 type quantities, there is significant danger.

 

[triatium]

Howdy

Regarding TEC coolers, can you get em for your gpu as well? Out here i aint been able to find squat! besides, would they use the normal wall socket directly, or pull htrough the psu? What can you get tecs for? How does one compensate for the condensation buildup around tecs though?

 

[Jofuss]

I've seen allot of TEC's that can rock off a power supply... but you would probably be best off building a +12v power supply just for them. As far as condensation goes, your best bet is to seal the area under and around the CPU with silicon/epoxy. Condensation isn't a problem if there is no room for condensation... and if moisture can't get in. Of course, I would recommend doing all of this in a very dry room, maybe run a dehumidifier in a closed room for a while... just be careful, dry air = static buildup.

 

[rubix_1011]

Yep, you sure as hell can get TECs for GPUs:

FrozenCPU has them

They are usually cooled via a watercooling loop, but as you may have found with your research, almost all of them are, and almost have to be with the amount of heat the hot side puts out. I am sure there are ways to keep them cool using heatpipes/fans, but the ones I have seen are H20 cooled. FrozenCPU has some pretty good stuff, but is somewhat expensive at times...just depends.