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Liquid Nitrogen Cooling at Home? 85

Posted by Cliff
from the stuff-not-usually-found-in-your-cupbord...for-good-reason dept.
newell98 asks: "Given the rise in popularity of water cooling systems for home computers, I was wondering how many slashdotters have played with the idea of cooling their system with liquid nitrogen? Lots of super-comps use them (or used to at least), and I'm curious about who's played with the idea of taking home computing to the same level?" The thing to remember about Liquid Nitrogen is that this stuff is generally not safe for home use. It must be stored and used with care or serious injury can result. I think this is why not-too-many people use such in overclocking. Water is by far more easier to obtain and is harmless to boot. Now, after saying all that, have any of you tried using liquid nitrogen in cooling a home or garage-built computer rig? What kind of safety precautions did you take, and how well did your cooling system work?
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Liquid Nitrogen Cooling at Home?

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  • Seriously, this is overkill. Excellent cooling can be achieved with a traditional water pump and thermocouples (TEC's, Peltiers, whatever). At least that way you don't risk freezing your fingers off.
    • by spt (557979)
      There is also a risk of suffocation.
      You don't need much liquid N2 to evaporate to make enough gaseous nitrogen to lower O2 levels in your basement
    • I setup a water cooled system on my highly overclocked CPU some time ago with some interesting results.

      The water block was made from a cutoff PCV piping cap mounted over an old heatsink. I used a surplus Peltier from All Electronics and I used my computer's power supply to run the Peltier. The water pump was a fountain unit sourced from an online supply company and was intended for 24X7 use squirting water in the air of someone's small pond.

      My first problem was SEALING the damned water block. Pinhole leaks were a PITA but with time I got a good seal using some SERIOUS automotive gasket sealer (Tough Stuff I think it was called). Nowadays you can buy built water blocks - I'd suggest doing this! They're not THAT expensive and you really don't need a super big one for this project. The second problem was that the water supply got VERY warm over the course of about 8 hours. This was 5gallons of water in an old cat litter bucket - sealed. There was actually steam rising from the water! Solving this was as simple as buying a trans cooler at the local auto-suply store. The water still got hot until I put a small FAN on the trans cooler - this is a must! With no airflow the trans cooler acted as a very poor heatsink. Melted quite a bit of snow on it though ;-)

      The above setup allowed me to nearly double the clock speed of the CPU I was using - an older Celeron. I don't recall my highest peak but I'm pretty sure I was hitting a Gig long before Intel released one. I ran Distributed Net's program so the CPU was tasked 100% 24X7. This program raises CPU temps noticably! Temp on the CPU sensor was nearly freezing measured from just under the CPU - I used a special add-in board to measure this as MBs at that time had no temp sensing. Unfortunatly this nice board is no longer sold or supported - it was called Heat Sentry I think.

      The best part about this whole system was the silence. I mean ZERO noise except from the power supply fan. The pump barely hums when it runs submerged and I was able to remove ALL of my case fans - there were many of these. I loved this system! I found that a small amount of Clorox would kill the bacteria that quickly formed (ick!) and had no need to experiment with Water Wetter or dishwasher spot remover in order to up the cooling ability - my CPU temps were stable and reliable.

      I did have some ongoing problems and one that finally killed the project until I have more time. First - condensation UNDER the CPU. Temps beneath the CPU were nearly freezing and certainly below dew point. Condensation would occasionally form around the pins of the CPU leading to an occasional system crash. Fixing this would sometimes require a hairdryer to dry the socket (sigh). I never tried dielectric grease or foam insulation under the CPU. Both of these ideas should be used if someone attempts to duplicate what I did. The second and worst problem was what occured when the system must've locked up early one day while I was at work. With no load to heat the Peltier it cooled WAY down. I came home to a dead system that had a solid block of ICE around the CPU socket area and onto the water block. As the ice furthest from the Peltier melted it dropped water onto my video card! The video card ended up fried but no other hardware was damaged. There were some tense moments with the hairdryer though! At that point I decided that the added frames in my game of the week and the extra keys in RC5 simply weren't worth the trouble of insulating everything. I pulled my fan\trans cooler out of the window and put it all away for another day. I DO still have the Peltier, tran cooler, water pump\resevoir, and a brand new aluminum water block on my shelf though. My unlocked AMD CPU now runs a bit over 1.4GIG with a good copper heatsink (aircooled). At some point when I've got time I'll water cool again as it was lot's of fun but I've simply not got the time right now.

      A feedback system to monitor Peltier temps would've been a nice addition as would a seperate power supply to run it. I was using a +12 and a -5 lead if memory serves. Without water flowing the CPU block's water hoses got pretty pliable with the heat and I was sure the water in there was nearly boiling. Monitoring the pump and the Peltier would be good ideas especially with today's super fragile CPUs. I noted that my plastic hose deteriorating over time from having been submerged in water for so long. I also had to cut the mounting ends on my trans cooler in order to up the water flow and lower back pressure. No antifreeze was EVER used - it lowers cooling ability as any gearhead can tell you. I used tap water with infrequent water changes once the system was closed up.

      Straight water does a VERY good job of removing the heat compared to convection and I predict that it won't be too long before we start using more advanced methods of cooling other than simply bolting on a still bigger block of heavy crap onto our CPUs. Cooling pipes at the very least look interesting as does liquid cooling sometime in the future. Lookup amatuer astronomy and how they cool the Peltiers that cool their CCDs to below freezing for ideas. These guys were way ahead of the Overclockers and I learned a great deal from some of their projects....

      P.S. A shame I didn't see this article when first posted. No Karma for me this time ;-)
  • by nelsonal (549144) on Tuesday March 05, 2002 @10:13PM (#3115809) Journal
    While liquid nitrogen is sexy, almost any coolant in a refrigeration system will keep almost any system cool very effectivly, and save quite a bit on not needing special insulation, and atmospheric needs associated with cooling.
    Of course if you live in the north right now you could just stick the thing outside, its supposed to be quite cold for the rest of the week.
  • Too cold? (Score:2, Informative)

    by CoolD2k (457145)
    I've seen this discussed on places like [H]ardForum before, and the general consensus seems to be that its TOO cold. Ceramic on the chips can become extreamly brittle and you have to worry about condensation, which will easily kill your system unless you use some type of non-conductive grease.
  • Just one problem (Score:3, Insightful)

    by caedes (157147) on Tuesday March 05, 2002 @10:39PM (#3115903)
    The major problem I can see with liquid N2 cooling is the formation of condesation on the CPU cooler. As soon as one drip hits the Motherboard the whole computer is out. :-( Water doesn't have this problem because the temperature is always above room temperature. So condensation cannot form.
  • Kryotech systems (Score:1, Informative)

    by voisine (153062)
    Here's a company that's been doing it for
    several years now. They had the first 1Ghz
    pc back in '99

    http://www.kryotech.com/thermal_acceleration2.ht ml
  • The Macintosh Apple doesn't require all this cooling. Maybe it doesn't matter to you, but I think it does. There you are, trying to work around the bugs in Abi Word and wondering if it is because your AMD processor is just too damn hot, and endless droning on and on and on is giving you THE WORST headache! Maybe if you move your box a little further away... maybe you can get by with just three fans if you underclock it a little bit... GOD that humming never quits!

    Macintosh Apple users have no fans! They don't listen to that noise day in and day out. How could this be? I don't know. I'm not saying the Macintosh Apple is a better computer. I'm only saying that users of the Apple don't have to listen to fucking fans all day long.

    Maybe you like all those fans going constantly. If you do, good for you. I'm only saying, you don't have to listen to that non-stop noise on and on and on and on...

    • by Anonymous Coward
      Ah, if only you were right. Unfortunately, you're not.

      I'd love my G4 tower that much more if it were silent.

      Hell, even my powerbook has a fan, though that one rarely turns on. Wish it did, so it'd stop burning my lap.
    • I'll bite.

      Macintosh Apple users have no fans!

      Neither do PC users. Their computers might, though.

      I'm only saying that users of the Apple don't have to listen to fucking fans all day long.


      No, but at least our OS doesn't come with "eep!" as a system noise. I'd rather trade a fan whine, which you quickly don't notice, over fucking inane samples. Hey, if you wanna throw ad hominems, I can throw 'em right back.
      And ya know what? My Athlon 1.2 has one case fan, one PS fan and one heatsink fan. I was smart and didn't buy the 64 CFM models because they're FUCKING NOISY! Buy Panaflo L1A's, 7 volt them, and you don't notice the fan whine.

      And didn't the 'fanless' cube have to have a fan on the video card if you got the beefy video option?

    • Hm.. just fyi.. in case you ever get stuck with (heaven forbid) an AMD Athlon machine for whatever reason, you could simply go and buy a Zalman 'flower' CPU cooler - has a silent fan, and cools very very well.

      For more info, go here :

      http://www.amdmb.com/article-display.php?Article ID =133&PageID=4

      Just because some people are prepared to put up with several screaming Delta fans in the case, doesnt mean that ALL PC users do - the noise drives me up the wall.
  • Bah (Score:3, Informative)

    by SuiteSisterMary (123932) <slebrun.gmail@com> on Tuesday March 05, 2002 @10:49PM (#3115948) Journal
    Get an electrically inert liquid (they're expensive,) a cooling coil, and a pump system. Suspend your mobo over a large resivoir, fill place the cooling coil in the resivior, fill with the liquid, and use the pump to draw it up, and let it flow over your mobo. It's like a waterfall!
    • Re:Bah (Score:3, Insightful)

      by Hadlock (143607)
      standard motor oil is non-conductive. so is synthetic oil. get a water (turned oil) pump, an oil radiator ($30 new @ autoshop), and some copper tubing. put fan on radiator (~8"x8"), and you're ready to go. kinda messy, but it works once you have it all in a closed system. you have a failsafe that if the pump dies, the computer still has to raise the temp of the oil above operating temp.
      • by addaon (41825)
        The problem with mineral oil (/motor oil/unscented baby oil) is that, while it's non-conductive when pure, it's noticeably hydrophilic. Yes, I know we all think of oil and water not mixing, but if you leave a container of mineral oil exposed to the air for several days, the water content goes from effectively zero to about 0.2%, if my memory serves me correctly. Not a hell of a lot, but enough to scare me in terms of conduction and corrosiveness.
        • conveniently, wal*mart sells ~12 gallon "tupperware" storage tubs for under 10$, which are both easy to cut and epoxy things (tubes, heat exchangers). once you got everything worked out, go buy another 4 gallons of oil @ walmart in 2 galong bottles for 3$ a piece (my and my friend priced everything out once, about 6 months back, comes to like 40$ total), and drain the current oil and put in new oil. presto. oh yeah. and put the top on it ;-)
      • You could use water to cool the motherboard by immersion or a spray bath too... if you were brave (and lived in a clean-room).

        Pure water is non-conductive. Yes, it is. Really, it is!

        However, if you add impurities to the water (mostly salts), it rapidly becomes conductive due to the free ions in salt.

        So, as long as your MB didn't have any contaminants on it, and you sealed it into a container, you COULD cool your MB/CPU directly by spraying cold water on it.

        Now, as for actually trying this with MY computer... ah, no.

        MadCow.
        • Would distilled water directly out of the bottle be good for this? I'd be interested in trying this out with an old junker PC that I have. Neat effect at parties.

          All hail the nerd!
          • Yes, distilled water would work for this. However, be careful about how "pure" the water is... if it's been sitting open for a while, I wouldn't trust it.

            Easy way to test: open the bottle, stick the two probes from a multi-meter in the bottle, and see what the resistance reading is. Ideally, it would be infinate. Try bringing the probes very close together in the water, but not touching, and see if it's still infinate.

            If so, you're good to go. The real question is, are there any contanimants on the MB itself that would make the water conductive?

            MadCow.
            • Hmmm the one thing that has always worried me about this is capacitence.

              Ever made a cap? Ill tell you *I* was tempted by the Capacitance constant of water man... 81!!!! Even some of the best plastics only have a constant of what around 5 or 6?

              Sure, the capacitence of two traces on a PCB is quite small... but add a dielectric with a constant that high and see what happens. It might be enough to make the capacitance between say... leads on a controller chip... become signifigant... and if you have a high frequency signal, then it could start to really suck, really fast.

              Anyway... this is all theoretical... Has anyone actually tried this?

              Will electrolosys happen in the water without salt contamination? If so, I might be worries about slow hydrogen buildup in the sealed case (and if the case isn't sealed, I would worry about contamination over time from dust particles)

              -Steve
        • However, if you add impurities to the water (mostly salts), it rapidly becomes conductive due to the free ions in salt.

          Pure water is non-conductive, but you won't keep it that way. During my PhD research, I tried cooling an electromagnet with deionized water. It works for a while, but it doesn't stay deionized for long. Once it starts to turn, things get messy and as well as shorts, you get corrosion and other problems.

          I ended up using paraffin, which I think you in the US call kerosine (not the stuff you put in aeroplanes!) It has a much lower heat capacity than water, but is at least easy to pump (I used a central heating centrifugal pump). It is not a fire hazard unless you make it into a fine mist or have something that could act as a wick.
      • I'm going to try it.

        Conveniently, I drive past two large scrap yards every day on my way to work. It just so happens that I want to pop into one of them to grab a central locking module, and the larger of the two has a fine collection of Citroens.

        So I'm planning on setting up a large tank of a light oil of some kind (probably diesel, it's pretty runny but not volatile - a bit hygroscopic though). I would use LHM or something but it's pretty inflammable, and *very* expensive (about £5/litre).

        So, pump it with a car fuel injection pump (about 20 gpm or so!) through a couple of oil coolers, blow through the coolers with a car radiator fan, and you've got nice cold oil...

        I need a PC to test it with, but I'll try overclocking the old P60 that's lying, dusty and forgotten, in a cupboard to, oh maybe, 66MHz? It should kick out plenty of heat...
        • aha! i'd never had thought to use a fuel injection pump. quite ingenious. the obvious is always the most elusive. i'm not sure if you'd want to put the power supply in the oil also, but that's an option. if you had a, say, 400w powersupply handy, you could submerse it in the oil, and run leads out of the oil to power the pump and fan, minimizing power cords/more efficent design.

          the p60's ran fairly warm, but the one i had running about 2 months ago never got too hot to leave your finger on the heat sink (w/fan), which tells me it's under 140*. if you were serious about running a decent (read:athlon) system, you might want to consider sticking a clear, small round 40w lightbulb in there. the type that powers/heats lava lamps, they're about $1.50 (a pound?) @ walmart. new athlons run @ about 45-60 watts, and this would better emulate a "speedy" computer, in addition to the p60.

          just a thought. email me and let me know how your project goes
          • I think I'd leave the PSU out, but if you put it in, disconnecting the fan might be an idea.

            You'll need a fairly hefty PSU to run the injection pump - the fairly small Bosch pump on my car is fused at 10A, and seems to draw most of that... The cooling fans, if you use radiator fans, will draw quite a high current.

            I never thought of using a bulb as a "dummy load" though, that's a good idea.
    • Cray 2 (Score:3, Interesting)

      by Bob_Robertson (454888)
      I'm sorry I never took a picture of the Cray 2 that was upstairs. There was a very pretty fountain designed to give a visual indication that the coolent was in fact circulating.

      If you were lucky, you could see a little bubble rise off the circuit boards.

      Of course, the Connection Machine over next to the Cyber was more flashy, with 64K little red LED's flashing all the time...

      Why, yes. I am a rocket scientist.

      Bob-

      • by Zurk (37028)
        if you have a connection machine do you have access to the source of that AI paint program that is demoed on it ?
        can you upload it someplace if you do ? Thinking Machines Inc. is pretty dead so it shouldnt matter.

    • Might I suggest mineral oil. It's non-conductive, not that expensive, and doesn't have the wonderful smell of a motor oil. I have actually seen a whole motherboard immersed in the stuff before.
  • Argh (Score:2, Informative)

    by flikx (191915)

    Just use R-134a, an evaporator, a condenser, a throttling valve, and a compressor. Create a sealed system with the components in the right order, and you're set.

    It's called a refridgerator, and it's much easier to use to keep your components cool enough. Keeping liquid nitrogen liquid, plus the hardware to pump it is way too expensive. Seriously, what a silly idea. Liquid Nitrogen, pfft!

  • Read this article (Score:4, Informative)

    by TheTomcat (53158) on Tuesday March 05, 2002 @10:59PM (#3115987) Homepage
    This guy uses Fluorinert and Liquid N2.

    http://www.octools.com/index.cgi?caller=articles/s ubmersion/submersion.html [octools.com]

    S
  • by Wakko Warner (324) on Tuesday March 05, 2002 @11:06PM (#3116020) Homepage Journal
    Put down the crack pipe. What on earth do you need to do that requires liquid nitrogen to cool it. This has got to be the worst "ask slashdot" ever, except for the one where the kid wanted us to do his homework for him.

    A supercomputer your PC ain't. Cool it the sane way.

    - A.P.
  • by josquint (193951) on Tuesday March 05, 2002 @11:13PM (#3116050) Homepage
    As anyone that's worked with extreme cooling knows, its the condensation that kills. Ever look inside a chest freezer? There's ICE on the walls.

    I've seen (and tried) lots of peltier combinations, cases in mini-fridges, etc. But as soon as you get far enough below ambient, you risk condensation on the components. I've cooled systems to about 30F(ambient about 70F) and fried an AMD 'cuz its pins were soaked in water.

    With N2, its LOTS colder than ambient, so condensation turns to ice VERY fast. So you have to insulate the shiat out of your proc.mobo. But from what i've seen, the o/cing advantage isnt a whole lot more because you're limited by sheer quality of the silicon, and the design of the transistors. They're just physcally too big to switch that fast, etc.
    my $.02(.01CAN)
    • Hey,

      I've seen (and tried) lots of peltier combinations, cases in mini-fridges, etc.
      ...
      I've cooled systems to about 30F(ambient about 70F) and fried an AMD 'cuz its pins were soaked in water.

      Presumably you did this for fun. If you want a hack to get you on slashdot but don't care about practicality, you could probably get something like this working properly.

      If you go to a scuba diving shop, they sell compressed oxygen with the water removed. This is because the pipes and fittings are made of rubber, and if there was water in the air, it would make them rot.

      Take your bottle of air home with you, and put it beside your fridge. Get an airtight box to put your PC in, and connect it to the compressed air. Ideally, you want a fractionally higher pressure than the outside atmosphere, so if there are any leaks, air will leak out not in.

      Put the whole contraption in your fridge, and set it running. The lack of water in the air around the computer should prevent condensation, allowing you to achieve lower temperatures more easily.

      Michael
      • The worst part is that it's the moisture in the air that helps cool things off... water can absorb a lot more energy than air can, so the more humid the air, the more heat it can dissipate
    • You could build a closed-system case where all the air is run through some de-humidifying gizmo...
      • It's case hack time!

        This sounds like not too bad a solution to everyone's concern of condensation. Build an air-tight case, use diver's oxygen as the atmosphere around the case, and have some kind of refrigerant for cooling.

        It seems to me from reading the above that the general concensus is that nitro is a no go. Too dangerous. But a case mod like the one mentioned above would solve the condensation problem.

        Of course it would make upgrading your cpu/vid card/ram/hard drive/etc an exercise in stretching the leevl of geek-annoyance to the max. But what a small price to pay for such a cool (heh) system!

        On the other hand, I'd never do it myself. Too much hard work!

        -JB
  • Give me a break (Score:2, Insightful)

    by NickDngr (561211)
    For the cost of the liquid nitrogen and the precautions needed to handle it safely you could just go out and by a faster CPU and motherboard. You're not running a supercomputer.
    • For the cost of the liquid nitrogen ....

      Actually, LN2 is really cheap. You can buy it for around $2 to $3 a gallon at some welding gas shops. You just need something to transport it in, a styrofoam cooler inside of a plastic tote would probably work, but you'd have to convince the gas dealer to actually fill it for you.

      You can make ice cream with it also without having to buy an ice cream maker. It's much faster too. Do a search on google if you want to try it, there are numerous sites about doing it.

    • What if you're trying to overclock the fastest processor available at the time? I'm assuming this guy wants to cool an x86 processor, so what if you have an XP 2100 or P4 2.2? I mean, really, who wants to overclock a 900MHz Duron? Well, OK, I guess some people do, but just buying a faster one isn't always an option.

  • by Snafoo (38566) on Wednesday March 06, 2002 @12:22AM (#3116389) Homepage
    Water is by far more easier to obtain and is harmless to boot.

    Sure, it's harmless to *boot* Aqua. But God help you if you attempt to install iTunes.....

  • some rather insane ppl (kiwi's too!) cooled the entire mobo using fluorinert (i probably spelled that wrong) and liquid nitrogen.

    There's two problems with this; one is condensation. The other is that your PC contains things like the CMOS battery and lots of capacitors which have some 'liquid' parts and die horribly when frozen.

    Also something else I just though of.. think about 'armies invading Russia, buttons becoming brittle and falling off' in terms of solder and board etchings..

  • by StandardDeviant (122674) on Wednesday March 06, 2002 @12:55AM (#3116514) Homepage Journal

    Speaking as a chemistry major who's spent entirely too much time in lab screwing around with the liquified gases, don't worry. Seriously. I mean, I guess unless you didn't have _any_ ventilation in the room where you were fooling with it. Still... You can hold liquid N2 in your hand, no problem. (there is an interface layer where your body heat has converted the N2 liq->gas, so it's "floating" on a cushion of gaseous nitrogen; basically just don't try to drink it or something retarded like that) I actually did the superconducting ytterium compound/levitating magnet thing once using superconductor pellets held in my hand with liq N2 poured on top. :-) So don't freak out, the liquified gases are pretty benign compared to some of the shite us chemistry f00ls mess around with... (as a still-not-so-evil example, 18+ molar mineral acids, so concentrated that they behave more like jelly than liquid) probably the only "liquid air" compound I'd be cautious around would be liq O2 and that's only because of the flammability aspect... I guess the main thing with these compounds is be careful about really really super cold metals because you could frostbite off of them (boiling, and thus gas interface, point is high)... wear work gloves or something if you're handling things in direct thermal contact with the gas (i suppose I should say liquid).

    sorry for any incoherency or bad grammar/spelling; very, very, very drunk at the moment ;-) wot can I say, chimay belgian ale is a great way to celebrate a radical success day at work...

    if you want to mess around with ReallyCold(tm) but don't have access to liquified gases, try dry ice + (alcohol, usually ethanol or something more esoteric than that but methanol would do in a pinch (non-chemist-speak: grab some dry ice from Kroger's or a party store and mix it with rubbing alcohol, waaaay colder than you'd get with normal ice and water. in a pinch, just find the cheapest nastiest grain alcohol you can... (everkleer, what?) ;-))). in lab I've hit the -20/40 F region using just dry ice and some not-to-uncommon alcohols. as I recall the F scale itself was calibrated using esoteric mixtures of dry ice and ethanol. which, if you think about it, highlights the total absurdity of the non-metric temperature system. always kinda wondered if the water-bases liquid cooling systems could be adapted to use this class of stuff as a coolant...

    Have fun, and play safe! (which, with these compounds, really means don't snort the vapors or drink the liquid)

    • First - my quals on this - I used to run an environmental test lab that used LOTS of LN2 for cooling - like 3000 gals a week

      I'll agree that LN2 is NOT as bad as some make out, but you DO have to be careful about O2 displacement if your using enough of it (I could tell you about the day the valve stuck, and we dumped 2000 gals of LN2 in a room in 4 hours), plus that vapor barrier can be pierced by splashing, or by dipping your hand

      That said, the item you cool to cryo temps is actually more dangerious than the LN2 iteslf

      If your only afraid of LOX, I guess you never got to play with LH2 - I never did, but a few of my friends did - it's the only stuff that scared them!

    • I had a physics teacher that used to put some on his tongue, in a similar demo. Once time, used a bit too much, and swallowed it. Gave a class a demo in the expansion of gas to liquid, as well as a belch fest.

      The problem with LN would be delivery and storage. I'm sure the local building codes will have a say, as well as for the delivery by semi-trailer.

      The Field Museum in Chicago switched to LN freezer units after a power failure cut electricity to them for many hours a few years ago.
    • Ah yes! Trust the drunken chem major :-D

      Actually I realy liked this guy's post - it has a playfulness that's all too lacking on /. these days!
  • by Mandelbrute (308591) on Wednesday March 06, 2002 @01:24AM (#3116623)
    I used to work with liquid nitrogen for metal testing, and it was also used to cool the electron microscopes. In a lot of movies, someone comes in contact with liquid nitrogen, then falls to the floor and shatters. Reality doesn't quite work that way. Anyone that has had a skin cancer "burnt" off with liquid nitrogen can tell you that it takes an uncomfortably long time to chill a small area of skin. I've had liquid nitrogen on my skin on occasion, and with breif contact it isn't the liquid that burns but any metal that the liquid has been in contact with. It takes a few minutes of immersion just to freeze a banana all of the way through. You just need to treat it with the same respect that you would treat a concentrated acid - keep it out of the eyes and off the skin.

    The big safety hazard is if you have poor ventilation and end up with low levels of oxygen in the room. Another hassle is that the liquid conducts elecricity. The biggest problem, however, would be your PC icing up. Thermal stresses could also be a big problem.

    Ultimatly, the question is why do it? If you have electronics that operate best at low temperatures then it makes sense, but PCs have components made to run at room temperature. Semiconductor behavior is temperature depenant, so the machine may not run as intended at low temperatures (the CPU may end up being made of a lot of resistors instead of transistors). Tin-Lead solder has known cracking problems at sub-zero temperatures, and not a great deal of strength anyway (Scott of the Antarctic got to stay there forever after the solder failed in fuel tins at low temperatures). Delamination of tracks from the fibreglass base could also be a problem if the board gets very cold - copper and fibreglass shrink at different rates.

    All of these things can be designed around. the easiest solution that I can think of off the top of my head is a great big lump of metal in contact with a resivior of liquid nitrogen under a feeder tank. When the CPU gets too hot, drip in a bit more liquid - just keep the liquid a long way from the CPU to keep all the ice and water away. a watercooled block would, of course do the same job if somewhat less efficently - or my favorite: airconditioning, big heatsinks and big fans. That way the user doesn't overheat either.

    • indeed, liquid N2 isn't all that dangerous. Just don't put your hand in a bucket of the stuff. What you CAN do is pour some of the stuff over your hand. Looks scary, but really isn't. Be careful though to pour it over, dont let it form a nice puddle in your palm.. that would be bad. But letting it flow over your hand was a favourite game back in the chem lab.. cos there's loadse fun with liquid N2.

      //rdj
      • Question for you: if I poured a bucket if liquid N2 all over an open notebook, would it cause the paper to wrinkle up like a bucket of water would?
        I'm guessing that it wouldn't smear ink, but I could be wrong. Have you ever tried it?
        • Question for you: if I poured a bucket if liquid N2 all over an open notebook, would it cause the paper to wrinkle up like a bucket of water would?
          The results are pretty boring - it would just get cold. I dropped a ball of crumpled paper in the liquid once, and nothing happened. However, it wasn't in there for very long, so there may have still been a gas layer between the paper and the liquid. There isn't enough water in the paper to freeze and shatter it like wetter plant material, and you don't have the glass transistion temperature effect that you have with some plastics (brittle at low temperatures).

          A lot of steels also become brittle at low temperatures (different mechanism) , but it's easy to order one that doesn't.

          As for pouring the stuff on my hand - I've done it during a superconductor demonstration, it wasn't deliberate, and it did hurt when I touched the bit of cold ceramic. By the next day the mark had gone.

  • Harmless? (Score:4, Funny)

    by andy@petdance.com (114827) <andy@petdance.com> on Wednesday March 06, 2002 @01:53AM (#3116724) Homepage
    Water is by far more easier to obtain and is harmless to boot.

    Ask Robert Wagner about water being harmless [who2.com].

    Visit dhmo.org [dhmo.org] for more information on the dangers of this all-too-common substance.

  • Yes, it's been done and, yes, you should've used Google [google.com].
  • by chongo (113839) on Wednesday March 06, 2002 @07:32AM (#3117406) Homepage Journal
    1. Use some reasonable ventilation

      While you may not need a ventilation hood, you should not store liquid nitrogen on a closed room.

      Pay attention to where the chilled nitrogen gas (that has just boiled) is going. Don't store or operate it near the top of stairs that lead down into a sealed room or basement as the chilled gas will flow downstairs and displace some of the air in the lower room.

      You should not have a problem if your rooms have reasonable ventilation / air flow.

    2. Be careful of chilled metal

      You can pour some amount of liquid nitrogen on your hand without a problem because the heat from you hand will form a boiling vapor layer and protect your hand for a while. On the other hand if you dunk something into the liquid nitrogen and chill it and then touch it, you can get a serious burn.

      A wire or aluminum plate that has been chilled to or near liquid nitrogen temperature will burn you almost instantly if you come in contact with it while it is still cold.

    3. Watch for icing and water hazards

      Ice and water can form around equipment where liquid nitrogen is boiling. The water runoff can ruin your hardware. The water can present a shock hazard as well.

      Be sure that your equipment is well grounded. Do not touch your system unless the power cord has been removed. Many motherboards and power supplies have electricity flowing in them even when the system is off. Always unplug before opening the system to reduce the risk of water condensation shock.

    4. Be careful around young kids

      The liquid nitrogen is a attractive hazard for kids. Be on alert of kids live or regularly visit where liquid nitrogen is in use. While you may take reasonable care, young kids may not. Young kids who see adults
      working with liquid nitrogen may get hurt if they try to play with it on their own.

      A young child can be seriously hurt if they try to touch or drink what they think is funny looking water.

    • An unexpected hazard may be present with liquid nitrogen. Oxygen condenses at its temperature and may accumulate. Materials next to it may combust and explode next to this wonderful oxidizer.

      Put an empty test tube in a flask of liquid nitrogen to collect oxygen. Then watch the pyrotechnic experiments of destruction...
    • My chemistry prof. at Va Tech (I forget his name) gargled liquid nitrogen repeatedly in front of all 400 of us in class. The vapor easily shot 12ft above his head. I was in the front row when he spit and the boiling beads vaporized at my feet.
  • First install your mobo and proc inside this custom case [nasa.gov]. Then use the patented location cooling system [nasa.gov] to lower the temperature to 4Deg about absolute zero [solarviews.com]. Now you only need to find 7.5 billion miles of CAT 5 ( and some batteries [nasa.gov] that last longer than 2 hours). Sure you can play Qake at 900fpss, but the latency is a bitch.

    SD
    • Launch your PC into the frozen wastes of space?

      Nope.

      If I'm thinking this out right, your PC will run hotter then hot itself.. Sure, the temperature is low, but there's very little or no heat transfer medium. Sure, when you leave it out for a week, it'll be near zero, but the second you start generating heat it'll just go up and up and up and...
  • With some simple parts from an old fridge, you can use somewhatsafer propane to cool your comp for a low price. You can even rig up some sort of grill to cook some burgers or something, plus mod your case to keep some beer cold and have a BBQ in your PC room
  • Liquid nitrogen has lots of uses around the lab, farm, shop and home. Cooling production computers isn't one of those uses and never was.

    Search google for liquid nitrogen ice cream for recipes.

    Try the string liquid nitrogen amateur scientist for experiments you can try at home.

    Unless you've got a farm, farm uses aren't interesting. However, if there are farms near by that use it, there may be a liquid nitrogen vendor who delivers to your neighborhood.

  • I still wouldnt.
    Nitrogen is quite expensive. is it really worth it to gain a few hundred MHz if the same affect can be made with a good watercooled setup?

    water cooling is safer. for you and the computer.
    no special handeling, if you run low or spring a leak or evaportaion becomes an issue just grab a glass from the sink. Nitrogen well not quite.

    you can also use inert (nonconductive) fluids, still slightly expensive but once again safer. and easyer to handle. You can just submerse your entire system in the fluid. And you wont need fans so it could also prove to be a silent or near silent machine depending on what kind of pump/liquid used etc....

    if you have the money to burn on nitrogen have a great time. but you could put it towards a nice system with one of the other cooling methods.
  • When exposed to the atmosphere, liquid N2 condenses liquid O2, which appears as a bluish fluid.

    Oxygen has a higher boiling point (-183 C) than nitrogen (-196 C), and forms highly explosive mixtures with many organic materials.

  • My primary work machine is a water cooled athlon. It runs pretty damn near ambient, and it runs cooler than it did with a heat sink even if I turn off the fan (e.g. silent running). This has been running 24/7 for about 4 months now with no problems whatsoever, so just go with that.. I have the chip overclocked as high as the motherboard multiplier will let me.

    http://www.nyx.net/~smanley/watercool

    That said, this has to be the most pointless ask slashdot I've ever seen. Why would you ask that? Niquid N2 is expensive and dangerous. Most motherboards and memory can't clock high enough to overheat a watercooled system. If you're going to spend 5 large on a N2 cooling system, why not just get a half dozen watercooled machines and cluster them?

    My next box is a Powermac on OSX, and the linux box can move to the closet. Quiet, and clustering is as easy as 1-2-3.

  • Get a small household air-conditioning unit, the kind where you have the big noisy part outdoors (on a balcony, window-ledge, or on the patio). Run some flexible tubing around the edge of the wall inside the room, leading to your computer case. Blow cold air directly in to the case.

    If you live somewhere humid, you might want to pump the air through a dryer unit. You could make this using the packs of crystals that you use for room de-humidifiers. I forget the name of these crystals (maybe anhydrous calcium carbonate? quicklime?), but in Europe they're sold under several brand names, Rubson is the one that springs to mind.

The superior man understands what is right; the inferior man understands what will sell. -- Confucius

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