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How to Run a Computer in a Sub-Zero Environment? 152

Posted by Cliff from the begging-to-be-overclocked dept.
Underdog asks: "I've seen tons of Slashdot articles on cooling hardware, but my company may be taking on the task of wiring a large sub-zero (as low as -14) warehouse with temperature sensors and the requisite network equipment and computers to read them. Our initial proposal includes at least a dozen acquisition computers, hung from the racks in the freezer. Does anyone have any experience with installing computers in extremely low temperature locations?"
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How to Run a Computer in a Sub-Zero Environment? More

How to Run a Computer in a Sub-Zero Environment?

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  • Heat it (Score:2, Interesting)

    by SlamMan ( 221834 )
    Run your network gear/servers in a heated environment. Temp controlled server room, spot cooler/heater feeding a rack, use the tools you like, but you're not going to find much that works properly (at the very least, doesnt void warrenty) in en environment that cold.

    • In addition ... (Score:4, Informative)

      by A nonymous Coward ( 7548 ) * on Saturday August 19, 2006 @08:37PM (#15942343)
      Putting heaters (computers) in an environment meant to be cold is just adding to the cooling workload. If the computer is at any decent operating temperature, it's going to be heating up the immediate surrounding area, and you don't want that.

      Put the computers outside. String sensors as needed. If you have to have electronics near the business end of the sensors, put those electronics under the floor or over the ceiling.

      Think of your refrigerator. Would you put even a small computer in there to keep your food warm?

      • Re:In addition ... (Score:5, Insightful)

        by theshowmecanuck ( 703852 ) on Sunday August 20, 2006 @04:33AM (#15943369) Journal
        I believe you are thinking too small. The OP mentioned the word warehouse. I doubt even several computers would make much of a difference in heat load. I have seen warehouse freezers the size of football fields. There is likely greater heat impact from people opening doors and gaps in insulation in an area that size than from computers. Even in a small warehouse.

        • Re:In addition ... (Score:4, Interesting)

          by zero_offset ( 200586 ) on Monday August 21, 2006 @07:03AM (#15947467) Homepage
          You're exactly right. My little brother drives a forklift in a 10,000 sqft subzero area of an even larger freezer warehouse. Different areas are kept at different temps. He works the coldest section which is used to store steaks and shrimp. He has to wear an enormous arctic-explorer-looking insulated coat, giant insulated gloves, and these military boots I bought for him that inflate (creating an air barrier). The workers are only allowed in the cooler for 15 minutes at a time. And this is in the middle of Florida where the outside temperature passes the 100 degree mark most days. I'd be worried about bearing fluid thickening or siezing up completely.
        • Build a small somewhat-insulated enclosure around the machines. Obviously you'd have to build it so that the machines don't overheat, but it should allow them to heat their own little areas over time, regardless of the overall warehouse temperature.

          • Re: (Score:3, Insightful)

            by theshowmecanuck ( 703852 )
            I made a reply to another comment that relates to this: Don't re-invent the wheel. :-) There are people who already make cold service computer (and other) equipment. Yeah, they probably just build enclosures with heaters in them, but at least they worked the bugs out already (if they didn't die from the cold :-). It is very rare to come across a situation that someone else has not already had to find a solution for and now markets it!

      • Re: (Score:3, Informative)

        by jackb_guppy ( 204733 )
        Switch view from computers in the warehouse to thin clients in the warehouse. Rack the actaul computers in a computer room, then run any of the KVM/VNC/Terminal on machines with NO moving parts that you want in the warehouse. This way cold or dust, does no effect the actual machines doing work and it lowers the heat build up in the warehouse.

        You want to look at ThinClients for this terminal feature. You may also want to look at ALL-in-One unit that has screen and processor built in to a single in closur

        • Re: (Score:2)

          by Cybrex ( 156654 )
          I don't have any experience with running computers in cold environments, but as long as thin clients are capable of doing the job that sounds like a great idea. Thin clients don't generally build up much heat at all, so there'll be less of a temperature differential stressing the components.

          It might also be wise to keep the components wrapped up as best as possible to keep air away from them. Otherwise I could see condensation becoming a real problem.

    • Re:Heat it (Score:4, Funny)

      by DarkMantle ( 784415 ) on Sunday August 20, 2006 @12:27AM (#15942950) Homepage
      Use intel Pentium 4's. They get hot enough to keep the rest of the electronics warm. ;) But seriously. Seal them off in a little cabinet. and keep that cabinet warmer. At least, say +5 celsius, that's about 40F so that conedsation doesn't form on the electronics and short it out. Remember, electronics run on smoke, when the smoke gets out they stop working.

    • Build the machine in a well-insulated enclosure. Add a heater. Arrange a thermostat-controlled requirement that the internal temperature of the enclosure be within the normal operating range of the computer before it is able to get power to boot. Require that it be within that range for a minimum length of time to allow for temperature stabilisation. Allow ventillation on demand (shutters) so that the computer can avail itself of the cooler outside environment if it gets too warm in the enclosure.

      I wo

  • Like in humid environments (Score:5, Insightful)

    by chriss ( 26574 ) * <chriss@memomo.net> on Saturday August 19, 2006 @08:00PM (#15942251) Homepage

    I have no experience with low temperature settings, but would assume that the main problem would be water condensating on the warmer parts of the computer. So the question would be how to make sure that the water does not short circuit anything. Experience may be taken not only from environments with low temperatures, but also from areas with very high humidity, which might cause similar problems.

    • I have no expirence in this either, but I wonder if submerging the non-moving parts in a non-conductive fluid or even just oil would work for you in keeping the electronic parts from water.

      Additionally, it may be best to do away with moving parts like fans (would you need them anyway?), hard dives (use flash storage), and CD-ROMs (maybe use a removable one just when you need it).

    • Re: (Score:3, Insightful)

      by Spazmania ( 174582 )
      Extremely low humidity is also a problem: you get static electricity which damages computers.

      The target humidity is 50% RH. Same as for human beings.

      • Re: (Score:2)

        by skogs ( 628589 )
        I disagree. I believe that is partially the point of that third prong on the wall plug.

        If you were opening up the computer and working on it, then you would need higher humidity or other ESD prevention mechanisms. However, just sitting there minding its own busines...as long as you and the other workers mind your own business, it will be fine. That big metal/plastic case is there for a reason - touch that part and you'll be fine. Don't touch the insides.

        Low humidity is perfectly fine for a computer to s
        • that is partially the point of that third prong on the wall plug.

          You're mistaken. The round third prong is strictly a safety device. Its actually tied at the breaker box to the same bus as the neutral (the long slot).

          The problem with the original two-prong setup was that if a device is plugged in backwards or if the socket is wired backwards (a common mistake) then the metal chassis of whatever machine is plugged in may be shorted hot instead of neutral. The machine would work as normal but if you touch it

    • Condensation shouldn't be a problem (Score:5, Insightful)

      by BobPaul ( 710574 ) * on Saturday August 19, 2006 @08:35PM (#15942337) Journal
      Since cold air has a lower capacity to hold water, warming the air should decrease the relative humidity of the air, bringing you farther from the dew point and make condensation less likely. Just let everything sit in the cooler to get nice and cold before you turn anything on and I think it should be just fine.

      It's just for things like water blocks with peletiers where the ambient air temp is really right and the heatsink is super cold that you have condensation issues (like a can of pop.) With the extremely cold (and thus dry) ambient air this issue goes away.

      My only concern would be if the freezer was often open for long periods of time letting in warm moist air, but even then I would expect it to condence on cold surfaces like the outsides of your cases, etc, and not on places that will short out.

    • Re:Like in humid environments (Score:4, Informative)

      by Schraegstrichpunkt ( 931443 ) on Saturday August 19, 2006 @09:53PM (#15942524) Homepage

      It's not just water that you have to worry about. Commercial-spec solid-state electronic components are typically rated for operation between 0 and 70 degrees Celsius. Electronic components conduct electricity better (or worse, in the case of many semiconductors) at lower temperatures, so even in a humidity-controlled environment, you could end up melting certain components.

      What you need is either computers that are built entirely out of industrial or automotive-spec components that are rated at -40 to 85 degrees Celsius, or you need a temperature-controlled server room that will keep the computers within the commercial-spec range. Both are going to cost money.

      • Re:Like in humid environments (Score:4, Informative)

        by (negative video) ( 792072 ) <me@NospaM.teco-xaco.com> on Sunday August 20, 2006 @05:06PM (#15945248)

        Commercial-spec solid-state electronic components are typically rated for operation between 0 and 70 degrees Celsius.

        Digital logic generally copes well with the cold, even if the manufacturer only promises down to zero Celcius (freezing point of water).

        The real problem is water-based aluminum electrolytic capacitors. They rely on liquid water for their electrical properties. Go below freezing and the capacitance drops by ~80%. Essentially all commodity computer equipment uses these caps in the power converters. If you take them below freezing, the power supplies flake out. Long-term reliability will be crap, even if they "seem to work".

        The advice in another comment is right: All the conventional servers and routers must go in a temperature-controlled room.

      • Re: (Score:2)

        by bbrack ( 842686 )
        Electronic components conduct electricity better (or worse, in the case of many semiconductors) at lower temperatures, so even in a humidity-controlled environment, you could end up melting certain components. better conductivity would lead to most parts running on less power than they would at high temp...

    • I believe you are correct (Score:3, Informative)

      by jd ( 1658 )
      All of the extreme cooling & overclocking sites talk about moisture prevention. Except at extreme cold temperatures (-40c or below), eliminating moisture should be the biggest problem. The solutions I've seen vary, but one popular method is simply to immerse the computer in a fluid that won't freeze, won't mix with water, won't conduct and won't corrode. There's a bunch of synthetic fluids (such as fluorinert from 3M) that meet these requirements. For a major corp, using "proper" tools is probably the b

  • Stable Operating System (Score:5, Funny)

    by QuantumFTL ( 197300 ) * on Saturday August 19, 2006 @08:02PM (#15942256)
    Most important thing is to use a stable operating system, that way it doesn't freeze up.

    Thanks folks, I'll be here all week!

  • Intel is your cold weather friend (Score:5, Funny)

    by Roadkills-R-Us ( 122219 ) on Saturday August 19, 2006 @08:04PM (#15942261) Homepage
    Just use any of the Intel processors produced in 2005. Of course, you might have to beef up the A/C to keep the warehouse from thawing...
    • Seriously--if you just insulated the case with a blanket of something, closing off the air vents, might the natural processes of the computer keep the internals warm enough on their own?
  • Use quad gpus and have them working (run a game in a windowed mode or something).

    Your negative 14 becomes a positive 114.

    (and since I don't know what unit of measurement you were referring to (fahrenheit or celsius?), let's just say celsius because that'd be hottest)

  • Close-ish I suppose (Score:5, Informative)

    by Artana Niveus Corvum ( 460604 ) on Saturday August 19, 2006 @08:07PM (#15942271) Homepage Journal
    I once worked for a company that had a computer closet on top of a mountain.It would often get -25 to -50F and sometimes much much lower. If you can find a way to enclose the computers they will keep themselves warm. We just put up some 1"-thick insulation inside the walls of the little shed and the two computers kept it at 40-50F in there at the worst times.
    • I suppose condensation could be a problem but we never ran into it (we had two P3 Deskpros up there along with a switch and a couple of IP-PDUs)
    • Most computers should work fine by sustaining themselves with their own heat, but I wouldn't power up a hard drive that I cared about if it was below freezing. I would try to find a tiered power-up system like hard core liquid cooled system use. These go between the power switch and the motherboard, so that powering on first pre-warms the components, and only when they got to an acceptable temperature does the system power on.

      Wonder if peltier pumps would be handy since you can simply reverse the current

  • Mac G4 (Score:5, Interesting)

    by LennyDotCom ( 26658 ) <Lenny@lenny.com> on Saturday August 19, 2006 @08:09PM (#15942276) Homepage Journal
    I left a Mac g4 dual Proc on my back porch in Connecticut for over 3 years summer winter and fall sometimes in winter the keyboard would be covered in snow and I would just turn it over anrd let it dry out it's still working today. I wish I had a Dell siting next to it for a comparasin.

    Sorry about spelling and grammer

    • Re: (Score:2, Interesting)

      by NMThor ( 949485 )
      This of course begs the question: WHY??

      • Re: (Score:3, Funny)

        by uncle_riley ( 655260 )
        This of course begs the question: WHY??
        Its something to do in Connecticut?

      • Re: (Score:2, Funny)

        by chill ( 34294 )
        Mac's probably weren't allowed in the house. He probably has a reputation to uphold and who knows WHAT would have happened if he was seen fraternizing with "one of THOSE machines". On the porch or in the barn is perfectly acceptable, though.

    • Re:Lenny's Mac G4 (Score:2, Interesting)

      by Announcer ( 816755 )
      That was just Lenny's way of getting attention. That's all. He's been posting about that incident here on Slashdot for... how long, Lenny? ;)
  • you might want to look into how phase-change cooling systems such as asetek (http://www.asetek.com/) deal with the problem. i think they use a heating element under the cpu to keep it above freezing, thus avoiding any nasty condensation problems. you might also have to watch out for contraction of the metallic elements involved - i recall hard[ocp] managed to destroy a chip with a phase-change setup because the heatspreader actually popped off due to the extreme cold.

  • Remote sensors (Score:5, Informative)

    by slasher999 ( 513533 ) on Saturday August 19, 2006 @08:11PM (#15942282)
    This may be missing the point of the OP, but why not install the computers elsewhere and use something like the Sensatronics sensors? The sensor device can be outside the freezer - only the probes need to be in that brutal environment. The device connnects via Ethernet. We monitor using Intellipool Network Monitor, although before we had that package I threw together a Perl script to poll the devices via snmp.

    • Re: (Score:2)

      by plover ( 150551 ) *
      Agreed. If you're simply looking to acquire data from sensors, there's likely an RF solution that doesn't involve operating a server farm at subzero temperatures -- just the sensors. Of course, you might be doing some really sophisticated analysis requiring precise timing, enoromous volumes of data, etc., but how much of that has to be both "precise" AND "real-time"? Can you collect the data offline with minimal hardware, and perform the analysis later?

      To me it sounds like you're thinking of an SPC-typ

  • Hard Disk (Score:4, Informative)

    by Detritus ( 11846 ) on Saturday August 19, 2006 @08:17PM (#15942301) Homepage
    The hard disk is the big problem. It will produce enough heat to keep itself warm and working if installed in an insulated box. It must be kept on at all times or an auxiliary heat-source like a light bulb must be provided when the drive is powered down.
    • Try using a Flash drive (Internal USB key?). Newer computers are capable of booting from USB, and this would remove the one primary source of failure (mechanical hard drive death). This would really only leave the cooling fans as possible points of failure, so good quality cooling fans would give you a very stable configuration.

      If you're using a Linux base for the acquisition computers, you can probably get away with tiny thumb drives (the lower bound today probably being set by commercial availability r

      • Re: (Score:2)

        by darkonc ( 47285 )
        Of course, even better than thumb drives would be just doing a network boot (depending on needs). Then you have thin clients with nothing in the box beyond power supply, motherboard and any necessary acquisition hardware.

        If you go with low power CPUs, you should even be able to run without fans, and allow the ambient temperatures to heatsink the CPU and power supply through the case. At that point you'll have the connectors as the only likely mechanical failure points.

    • Re: (Score:3, Informative)

      by nmos ( 25822 )
      It must be kept on at all times or an auxiliary heat-source like a light bulb must be provided when the drive is powered down.

      A decent heat source would be "heat tape". It's normally used to keep pipes from freezing. It's basically a long strip that works like an electric blanket with a thermostat that turns it on at temperatures around 40f.

       

  • Liquid Cooling/Heating (Score:2, Interesting)

    by wrfelts ( 950027 )
    Although it may be cost prohibitive, the concepts used when cooling a computer through liquid emersion [electronics-cooling.com] may do well in this sort of environment. If the expelled heat of the computers is not enough to keep the liquid up to optimal temperature, you can conserve some energy by utilizing the excess heat from the refrigerant system. This method can also be used to raise the "PC-tank" environment up to optimal for a "cold boot" (sorry, could't resist.) The expelled heat of the computers will add to the load of
  • Have you looked for similar businesses to this company, to see what they did and how they did it?

  • I've done this a lot. (Score:1, Insightful)

    by Anonymous Coward
    Electronics likes to operate in a cold environment. Mechanical stuff doesn't like cold temperatures because the lubricants usually get gummy. I used to put remote equipment in the Canadian arctic. Even commercial grade (as opposed to mil-spec.) ICs were happy to operate at temperatures below -40 deg. F.

    There are many boards available which can be passively cooled albeit at sub GHz clock rates. If I had to do it right now, I'd use Damn Small Linux on a flash drive. The guys who put computers in their ca

  • Overclockers have this problem (Score:4, Informative)

    by zaguar ( 881743 ) on Saturday August 19, 2006 @08:34PM (#15942336)
    When some overclockers use sub-zero equipment, condensation becomes a big issue. With stuff like LN2, some OC'ers dump the entire motherboard into a non-conductive tray of oil. You could look into something like that.

  • Thoughts (Score:5, Informative)

    by Spazmania ( 174582 ) on Saturday August 19, 2006 @08:36PM (#15942341) Homepage
    Transistors are designed to behave within a specific range of voltages and switching speeds for a particular range of temperatures. Most COTS electronics are targeted for an ambient temperature around 72F and work best at that temperature. When temperature extremes are needed, the transistors are actually doped and constructed differently.

    That having been said, there are some things you can consider:

    1. Do the computers really need to be in the freezer? If there is a way to build it so that they're not in the freezer, do it.

    2. Enclose the cases with no ventilation. At subzero ambient temperatures they'll lose enough heat through the chassis. Insulate until the internal temperature is reasonable but not so far that it'll retain too much heat.

    3. Install an electric heating coil in the case to bring the temperature up if it drops too low.

    4. Underclock everything on the system: the CPU, the PCI bus, etc. Stretching out the clock cycles should give you a greater tolerance to the change in how the transistors behave and lower than expected temperatures.

    5. Don't forget to consider the impact of the heat load on the freezer. You said computers with an S. Each one is going to dump 200 watts or more of electric heat into the freezer 24/7. Does the freezer have enough excess capacity to handle that and still do its job?

  • Toughbooks (Score:3, Interesting)

    by Saval ( 39101 ) on Saturday August 19, 2006 @08:39PM (#15942347) Homepage
    At least Panasonic Toughbook-29 seems to meet your temperature (and humidity) specifications:
    http://www.panasonic.com/business/toughbook/df_tes t.asp#12 [panasonic.com]

    Though that is only part of the solution...

    • Re: (Score:3, Funny)

      by pimpimpim ( 811140 )
      I'm not really sure about those machines, it looks like they have some real problems coming onto them after being dropped, just look:

      Drop Test The Drop test was performed in accordance with MIL-STD-810F, Method 516.5, Procedure IV (Transit Drop Test). The Toughbook 28 was sequentially dropped in non-operating mode, onto each face, edge and corner for a total of 26 drops from a height of 36 inches. The drop surface was defined as two-inch-thick plywood over a steel plate over concrete. (...)

      Results
      The T

  • take a cue from nasa: they supply all their deep space equipment (from probes to rovers) with portable heaters. best way to keep them working would be to insulate the box and stick a small thermal element inside on a thermostat. (it should only need to come on btw, when the box isn't running - computers heat themselves just fine otherwise ;)
  • Overclock the hell out of them! You're running in an air cooler's wet dream!

  • This [lsu.edu] should give you a lot of help. They fly instrumented balloons in Antarctica. The server does not seem to be responding right now, but that should help you find what you need.

    • Re:ATIC (Score:5, Funny)

      by Anonymous Coward on Saturday August 19, 2006 @09:07PM (#15942415)
      Taking advice from people who can't keep their server running isn't advised.

      • Re: (Score:2)

        by twitter ( 104583 )
        Taking advice from people who can't keep their server running isn't advised.

        Yeah, yeah, they are using M$ for their server at LSU, so I imagine they don't know what they are doing webwise. They don't use that junk for their instrumentation or any other place they care about.

    • Re: (Score:2)

      by Tim C ( 15259 )
      Kind of ironic, linking to a PowerPoint presentation, given your sig...

  • One thing the OP didn't tell us is whether the temperature is going to be a stable -14 F, cycling up and down, or changing erratically. If the temperature is going to be changing between -14 F and room temperature, then probably it's not practical to put an ordinary computer in that environment. There's also the question of whether the machines are going to stay powered up 100% of the time; if so, then the temperature inside the case will probably be relatively toasty while they're on, but recovery from a

  • Google it? (Score:3, Informative)

    by martinde ( 137088 ) on Saturday August 19, 2006 @09:13PM (#15942423) Homepage
    I ran across this [bsicomputer.com] googling "industrial pc for low temperature environment" (without the quotes):

    It's specs say it has an option to go down to -20C operating temperature.

  • A Chicken Will Do (Score:5, Interesting)

    by KidSock ( 150684 ) on Saturday August 19, 2006 @09:19PM (#15942430)
    During the Cold War it was proposed that a live chicken placed inside of nuclear bomb would be sufficient to keep things from freezing up. In the case of a computer I would suspect the ambient heat of the electronics would be adequate to keep things at a reasonable tempurature provided the compartment and insulation was good enough.
    • During the Cold War it was proposed that a live chicken placed inside of nuclear bomb would be sufficient to keep things from freezing up.

      But they canned the idea when they realized that the chicken would have full access to the warhead's controls.

    • Re: (Score:2)

      by CAIMLAS ( 41445 )
      I don't know much about nukes (except they're not generally a good source of nutrition), but I do know that a cold environment with a warm source - or vice versa - will result in a great deal of condensation, frost, and potential hardware problems.

      • Re: (Score:2)

        by nmos ( 25822 )
        but I do know that a cold environment with a warm source - or vice versa - will result in a great deal of condensation, frost, and potential hardware problems.

        Well, a cold device in a warm enviornment will cause condensation (think glass of ice water on a warm summer day) but the other way around isn't a problem.
  • If you enclose your gear in an airtight box it still might get colder than you would like. You can just put a light bulb in the box (wattage would vary depending on the size of the box) attached to a thermostat. Light bulbs work just as well as a heating coil, and you can use photoresisters to instrument the box and tell you when the bulb burns out.

    You can even run the thing with a digital thermometer, BASICstamp (and board) and photo-resister, you can run the whole thing
    from an embedded system and be com

  • Do you *really* need that many cold computers? (Score:5, Informative)

    by munpfazy ( 694689 ) on Saturday August 19, 2006 @09:27PM (#15942450)
    For what it's worth, we've always built room-temperature enclosures to house electronics gear and PCs for the work we do in Antarctica. It's almost always easier and cheaper then trying to insure all your equipment can survive harsh temperatures.

    For the odd piece of gear that needs to survive out in the open, we test them thoroughly in a freezer ahead of time. Some things - in particular simple solid state single board gear with no moving parts - seem to do quite well down to -50 C or lower. But, as capacitor values drift and sockets and connectors contract, even some likely candidates fail. Anything with lubricants or precision mechanical parts (drives, fans, etc) are almost certain to cause trouble. Expect your batteries to die and a some read-write storage media to fail.

    But, is it really necessary to put a dozen full computers in this environment? It sounds like serious overkill to run a bunch of temperature sensors. If you absolutely need to use PCs, see if you can place them just outside of the cold space and run cables. Or, if that's not possible, put them all in a single, insulated, enclosed space with an active thermostat and some electric heaters. Make sure that when all the PCs are running at full tilt the temperature in the box is slightly below your target, so that you can control it with only a heater.

    Better yet, replace the PCs with small readout and control boards. If all you need is to record temperatures to within a few tenths of a degree, building a board that will give you dozens of channels and a straightforward digital interface should be a few day's work for a reasonably competent engineer - and fabbing them may well cost less than a dozen PCs. You can then hand pick parts and packaging that is rated (or tested by you) to low temperatures, or you can build in very small heaters that keep individual parts warm without dumping too much heat into the environment. You may even be able to find such a product off-the-shelf if you hunt around.

    If you absolutely must have PCs, see if you can't find a small single-board computer that will do the job. Test several over dozens of thermal cycles in a freezer before deciding to use it, and buy a bunch of extras.

    • Re: (Score:3, Informative)

      by gremlin_591002 ( 548935 )
      It would be silly to build a custom board for this kind of work. I deal with embedded PLCs all day, they are all solid state and can read sensors wired to them from hundreds of feet away, even longer if you use 4-20ma. Lots of different models with anything from 4 inputs to 128. This is the brand I use: www.kmc-control.com Ethernet connection available on several of the models, but for this kind of work, RS-485 is cheaper and more reliable.

  • RS485 Sensor Network (Score:3, Informative)

    by NoMercy ( 105420 ) on Saturday August 19, 2006 @09:40PM (#15942473)
    If I was riging it up, I'd use something like RS485 into sealed units with a small custom board in a sealed unit with the sensors hanging off of that. Then you only need one or two PC's outside plugged into the networks of sensors to read off the data and log it.

    You could plug pretty much any PC with a serial port in, with a converter like:
    http://www.advantech.com/products/Model_Detail.asp ?model_id=1-1TWNLI [advantech.com]

    The only dificulty left is working out what kind of connectors you can use, if it's all hard wired, then it might be fine to wire the cables though sealed gromits into the boxes for termination.

    The protocol could be quite trivial too, say send a couple of characters like R521,53 to say you want to read sensor 53 on unit 521, it'd run out over the bus, get picked up by the right unit, and reply a short time later with something shocking like V521,53,258 (where 258 is -15 degrees in kelvin).

    But don't take my word for it, just build a low temprature version of:
    http://www.elecdesign.com/Articles/Index.cfm?AD=1& ArticleID=6191 [elecdesign.com]
  • You're actually planning to massivly overclock arn't you?

    But I think the leading edge OC'ers have some of the same problems, Condensation, temperature changes warping parts (can pop IC's off boards.) So there may be common solutions. I recall a story of a fellow who suspended his computer in Mineral Oil (non-conductive, used inside electrical transformers) one advantage of which is to naturally exclude water; however I don't know it's freezing point, but there was also discussion about 3M or DuPont producin

  • Styrofoam building insulation (Score:4, Informative)

    by adminispheroid ( 554101 ) on Saturday August 19, 2006 @09:58PM (#15942535)
    I've done stuff like this with computers for balloon payloads that go up in the stratosphere, where it's around -50 C. Here's two tricks that should help. Trick number one is build a box out of styrofoam building insulation and duct tape. Assuming you're in the US, you'll see a number printed on the insulation like "R5" or "R10." That's the thermal resistance, in BTUs, hours, deg F, and square feet. No, I'm not making that up. Guesstimate the power dissipation of the computer and use that to make the first design, then test and iterate. You'll want to stick a thermometer on the case or other convenient location. If this isn't reliable enough, then trick number two is design your insulated box to run a bit cold, and build a thermostatically controlled heater. We usually designed our own, because we like to do things the hard way, but I believe at someplace like Newark Electronics you can buy a little package that contains a heater and a bimetallic thermostat, you just supply the power.

  • Doing it all wrong (Score:5, Informative)

    by grozzie2 ( 698656 ) on Saturday August 19, 2006 @10:16PM (#15942577)
    The first step is to go back and re-visit your overall design. You only need sensors in the freezer, you dont need to put the computers in there. What you really want to do is go shop around in the industrial supply channels, and you will find all sorts of sensor equipment ideal for the job. You probably want temp sensors that speak ethernet out the other side, then either wire the place with ethernet, or use some wireless gadgets to further bring that data out of the freezer. For the life of me, I cannot fathom a system that needs a dozen computers to handle the sensors in a freezer. How many thousands of sensors are you putting in ? One computer (in an office outside the freezer) should easily be able to process the data from a few hundred sensors, all arriving in real time over a dedicated ethernet run.


    I've done lots of industrial installations, in places where -14 would be considered 'toasty warm' compared to outside temps in the middle of winter. If I saw a proposal that includes putting full blown computers in the freezer, the first thing I'd do, find another vendor, this one obviously has no clue when it comes to embedded industrial equipment. Mil grade sensors that are good to -40, may not be a dime a dozen, but, there's lots of them out there that you can just buy and install, which will happily feed the data back to a computer sitting in an office somewhere.

    The bottom line, if you are going to put rack mount pc's inside the freezer, do your customer a huge favour, and reccommend they find an expert in the field. You will be saving yourself a long term support nightmare, and your customer a whole big pile of money, because the proposed solution is kind of like taking money and flushing it down the toilet.

  • There is absolutly no reason to have your equipment in there. There are units that can scan quite a few thermocouples in various areas. Then there is now also equipment that can be driven directly over tcp(pw on unused pairs) think two wire sensors. I could tell you several ways to do it. But really, get a good industrial electrical contractor to do this for you. There are many things your not even thinking about, such as sensors getting hit etc.
    • Please, get somebody that knows what their doing

      I should paste one of these standard "Ask Slashdot" forms here, like: "I work for a top 500 company and am responsible for the new e-mail system, should I use some obscure undocumented mailing system because an 18yr old on slashdot has good experiences with this on his home server?"

      I'm a nerd as all of you, and the subject is pretty cool (pun!) and interesting. Also there are nice reactions from people that actually dealt with situations like this (in the

  • Ok first look in the right place (Score:4, Insightful)

    by WillRobinson ( 159226 ) on Saturday August 19, 2006 @10:44PM (#15942663) Journal
    You looking on slashdot, you dont need a IT guy, you need a good controls guy.
    This is cakewalk for them.
    You will want a HMI for instance google for Wonderware.
    Field sensors can be done is several ways.
    PLC's with say up to 128 thermocouples, which would be in enclosures to keep out moisture (nema 4) talking to ONE
    pc or mutiple (MMI) (Man Machine Interfaces) vi tcp.
    If I knew your layout, I could tell you completely. But really, get a good controls or I/E guy.

    • PLC's with say up to 128 thermocouples,

      I would not use thermocouples. They need expensive wiring and they are not particularly accurate if you want to measure differences of less than 1 C. A thermistor with a four-wire cable (2 for voltage supply, 2 for measuring voltage over the thermistor) is more suitable for such applications. With a thermocouple will need a thermistor anyway for the cold/warm junction compensation. There are companies that make cheap USB thermometers ($30 per piece) based on thermis

  • Hard Drives don't like cold (Score:3, Informative)

    by MichaelKaiserProScri ( 691448 ) on Saturday August 19, 2006 @10:48PM (#15942677)
    I had the pleasure of setting up a couple of systems in an unheated office in Maryland, in Februrary. It was "only" 20 in the room, but the hard drives did not want to spin up until they warmed up. Aparently there is some sort of lubricant on the platters that turns to GLUE at 20 degrees. So.... Put the servers outside the cold area. Make everything in the cold area diskless. My father used to work for a company that made cockpit voice recorders. The bay the recorders get mounted in is unheated and unpressurized, so it gets 30 below and very low pressure. To compensate for that (and for condensation) they burried the entire circut board in a block of epoxy. If you run terminal server, you may be able to find a dedicated terminal server client that you can just bury in epoxy. The hardest part will be the monitor. As far as I know LCD will freeze at that temp and just not work. CRT will potentially have condensation problems. I don't know enough about how plasma works to know what that will do.

  • Don't (Score:2)

    by XNormal ( 8617 )
    Convert the temperature readings with voltage-to-frequency converters. This digital signal is very robust and can be carried over long distances on unshielded wires with no loss of accuracy. The frequency counters and computers can then be mounted outside the warehouse. You can put a DC power supply and an AC signal on the same wire pair with AC coupling for the signal.

    I'm pretty sure it's easier to find a V2F converter to run at these temperatures than PCs and networking equipment.
  • if you need something like this then you can afford to pay for somebody who knows wtf they're doing and avoid asking a large group of anonymous persons who'll give no warranty.

    I once had a guy ask me to install security cameras in his shop (i do this so no problem) but when he took me to the freezer as said he's had trouble with employee theft and wanted a camera in there I sent him to a group that can do that type of installation, you should too.
  • How to run a computer a sub-zero temps? Place the computer in a really f***ing cold place, connect the cables and fire her up. After about a year the fans start breaking up because their bearings can't handle freezing. Other than the fans, the computer will just run forever...

    Don't know whether you're talking about F or C, but it really doesn't matter as they're pretty close to each other near -35 degrees...

    I've had my home server sitting outside in a Finnish winter/summer for the last five years with zero
  • Why would you want to subject the computers themselves to potentially hostile environments? there are dozens if not hundreds of solutions out there which would meet this need. I personally know a guy who writes software to control and monitor temperature sensors placed in grain elevators. as far as I know the technology would work just fine in a freezer (though its targeted for an outdoor grain elevator - not much of a difference i nterms of hostility). it communicates with the servers over shortwave band (
  • Yes, see here [gdargaud.net]. Sorry, don't have the time to comment right now.
  • Cant you just isolate the sensors from the computers? Even the displays can be run remotely..

    Put the computers/network stuff in a heated closet and run long lines out to the sensors?

    Bar that, dont use any moving parts in your computers that *have* to be out on the floor at least..
  • All of the top modded posts seem to be advocating using off the shelf computers, and keeping them warm. The question I ask, is how much processor power do you really need?

    If I were looking for a computer for that environment, I would be looking at Rugged off the shelf (ROTS) (As opposed to commercial off the shelf - COTS) products. Single board computers are your best friend in these conditions. Yes, you will pay a premium for them, but extended tempurature models operate down to -40 C. For example:
    http [versalogic.com]
    • This is good advice, to which I'll add a few more points.

      LCD displays have slow response at low temperatures. Be sure any you use is rated for the cold environment you're dealing with. Standard (less expensive) ones aren't suitable for sub-freezing temperatures.

      Avoid moving parts. Consider a flash-memory card instead of a hard drive for the cold room systems (check the temperature specs for the flash, as well). If there must be disks, put them on a server located in a more forgiving environment.

      You may also

  • Find yourself a good single board computer with an extended temperature range. Within the PC/104 and PC/104+ families it isn't hard to find SBCs with an operating temperature range of -40 to +85 C, and they're built to handle humidity. I've had good luck with Advantech [advantech.com] devices; Diamond Systems [diamondsystems.com] makes SBCs with data acquisition systems built-in which might come in handy for your application.

    Whatever SBC you get, be sure to pair it with an extended (aka industrial) temperature range boot device. Industria

  • it will not be sluggsh hard-drives or condensation causing shorts, both will be a problem given time, but before they do, what's mostly likely to blow out the computers is the electrolytic capacitors freezing and shorting out due to ice swelling. Make sure the motherboards cards and power supplies are rated for the temps expected and expect them to be very expensive mill-spec stuff. Otherwise keep them in a heated enclosure kept above freezing.
  • I have a NEMA box full of network gear out in a swamp in New Hampshire (for a wireless network) and it can get to -30 here.

    We put an AC-thermostat gizmo in the box, put in a ceramic heater, and set it to 30 degrees F. When it gets too cold, the thermostat kicks the heater on - when the box gets warm enough it shuts off. The box's insulation means the heater doesn't stay on for too long (it uses about $5 worth of power a month in winter).

    The wireless gear generates little heat itself (the wall-warts are pr
  • You'd be amazed at the very wide operational temperature ranges in which you can operate many devices, if you can just maintain BOTH the internal moisture level and ambient temperature (plus/minus 5% relative humidity, plus/minus 5 degrees Fahrenheit).

    Change is bad.

  • If you want to perform temperature measurements in a cold storage warehouse don't use PC's at all. Instead use an Adam 6018 [advantech.com] in a Nema 4 or Nema 12 electrical enclosure with a thermostatically controlled heater. The cost of this implementation versus PC data acquisition will likely be an order of magnitude less. Wire the devices together with Cat5 made for low temperature environments. The insulation on regular Cat5 will become very brittle in the freezer.

    Some tips for dealing with the Adam 6018... The sa

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