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How to Run a Computer in a Sub-Zero Environment?
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?"
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.
Mod point free since 2001
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.
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Most important thing is to use a stable operating system, that way it doesn't freeze up.
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Just run regular Pentium 4 chips. You still may need a fan and heatsink.
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...
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)
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.
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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
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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.
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.
"Does anyone have any experience with installing computers in extremely low temperature locations?""
A small thermostat electric heater is required in an appropriete enviromental box (no condensation 'silica gel's your friend',thermally insulated).
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.
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Although it may be cost prohibitive, the concepts used when cooling a computer through liquid emersion 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 the refrigeration system as a whole and needs to be calculated into the whole power efficiency equation.
Good luck.
How about having them submerged in vegetable oil or some equally inert non-freezing liquid? It would prevent condensation problems, and I'd think that cooling (hah) wouldn't be a problem.
Have you looked for similar businesses to this company, to see what they did and how they did it?
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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 cars have the situation totally cased (pun intended). Get one of the little Pico power supplies which can run off a small linear fanless power supply.
You have much more to worry about the heat in the summer than the winter cold.
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.
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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.
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?
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
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?
Infuriate left and right
At least Panasonic Toughbook-29 seems to meet your temperature (and humidity) specifications:s t.asp#12
http://www.panasonic.com/business/toughbook/df_te
Though that is only part of the solution...
--Saval
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 ;)
http://kered.org
Overclock the hell out of them! You're running in an air cooler's wet dream!
This 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.
Friends don't help friends install M$ junk.
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 power outage could invove a nasty swing in temperature that might cause stuff to fail.
The weak point might be the hard disk, in which case it might be a good idea to use flash drives instead, or connect to storage over a network.
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Due to the location of the system being a sub-zero environment and the major problem being the extreme differences between the normally high heat of a computer with the arctic like temperatures in the freezer there is but a simple fix. Use an airtight, insulated box with a thermostatically-controlled liquid-cooling system preferably with a liquid that will not freeze at the temperatures. The initial start-up will prove to be interesting due to the intricies of being so cold at first. A space heater might be necessary until heat builds up inside the computer. USE NO FANS! All connections to be made should be routed through a single hole that is sealed immediately with an expansion insulating foam, silicone, or caulking. Any questions?
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I ran across this 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.
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.
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.
n entshop/sensors.asp
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 comfortable with the reliability, even. And you get a neat project.
http://www.parallax.com/html_pages/products/compo
I getto deal with things like this at work a lot. Here's the short of it.
In general, the "commercial" temperature range for electronics is 0 to +70 Celsius. Most of your off-the-shelf stuff will be in this range. Some embedded systems are available in the "automotive" or "industrial" temperature range of -40 to +85 Celsius; if you can get equipment in that range, you'll have nothing to worry about. You'll want to check the specs on all your equipment; some of those switches may well be industrial temperature range, since the parts in that temperature range don't usually cost that much more these days. (There's also the "military" range of -55 to +125 Celsius, but that's probably overkill for you.)
Failing that, I would recommend you keep the commercial-temperature equipment in an insulated enclosure (room, box, cabinet, whatever you can rig). Put a thermometer on that enclosure so you can check on it without opening it. Then put an electric heating element (oelectric blanket, maybe?) on the bottom and hook it up to a thermostat so it kicks in when the temperature gets near 0 Celsius. If you do that, you'll likely find that the heating element keeps it warm when the computer gear is off, then when the computer warms the place up, the heating element will simply stay off (that's why you want the thermostat). Also, it's important to let the heater get the enclosure up to temperature before you start up the computer; you want to give any condensation time to bake off.
Hope that helps.
I worked in the Arctic (-18F) back in the eighties' and we kept the computers indoors and ran cables to the sensors outdoors. Sensors are cheap and plentiful. Wires get brittle in the cold and break easily.
Enthusiasm diminishes with each trip outdoors: dressing for weather, exiting warmth, finding and fixing each problem, returning to warmth, getting coffee and food, finding out next problem.
I do not complain about the cold anymore!
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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.
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.
p ?model_id=1-1TWNLI
& ArticleID=6191
You could plug pretty much any PC with a serial port in, with a converter like:
http://www.advantech.com/products/Model_Detail.as
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
We spent a lot of money on mil-spec cables, thinking they would be better in the harsh arctic environment. Hah! They would crumble if you even looked at them. That was our education in mil-spec. The mil-spec for the cable we bought was for whether it would mildew in the tropics. We ended up using rubber insulated consumer grade cable which worked great.
You forgot to mention that everything takes twice as long when you're working under adverse conditions. It's hard to hold a 'scope probe steady when you are shivering. You get clumsy and your IQ goes down under such circumstances.
If I had to install the equipment mentioned in the story, I would make darn sure it is easily accessible. Trying to change a board when you're standing on top of a ladder with your fingers freezing is a recipe for disaster.
I'm not really sure about the poster's specific needs, but why not just go with a mainframe-terminal setup? Keep the server in a room temperature enviroment and then run some CAT5 into the terminals that are in the subzero area.
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 producing chemicals specifically designed for this purpose: little thermal expansion, no electrical conductivity, high thermal conductivity, wide range of tempuratures at which it remains liquid.
Another problem I forsee is the cold air and low humidity may lead to static electric buildup.
Ummm. I don't think you have to worry about them being wet or dry. The article said sub-zero. The air will have 0 humidity. As for the cold I don't think it will be that much of a problem to keep them above freezing and they *should* work just fine. Since they generate their own heat use that to your advantage by restricting airflow from the PSU fan and plug up the additional fan ports then grab a can of glue and glue some insulating foam on the sides of the metal case. The foam is cheap 5 bucks at a home improvment store for a 4 foot bt 8 foot piece.
As long at the machine is on it should keep it's self warm enough and the isulation will keep the heat in and not warming your freezer. For further warmth just run folding@home on a P4.
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.
Unless of course you have workers in the sub-zero environment. Speaking from experience (Kroger Distribution Center Freezer), patches of thin ice are very common with so many people going in and out of the room. Several people (or dozen people) breathing in a room with cause a decent amount of ice buildup on various surfaces.
I came, I saw, She conquered.
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.
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 to reverse the heat/cool direction...
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.
Static Electricity is another major factor in any Arctic temperature, low humidity environment. Alway touch a grounded frame before touching any electronic equipment.
Other concerns: We had Scripto and felt pens dry out if left open in warm rooms. Frozen pens might recover and be usable, but not all!
Inspect and inventory everything! Decide what can and what cannot be stored in the cold!
The only thing new in this world is the history that you don't know.[Harry Truman]
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.
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.
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 antartics, yay!). But the company of the poster is running a business, and can not afford to fool around. Monitoring systems in food or chemical industry are a field on its own. There are huge industry expositions and specialized journals that focus just on this subject. Probably there is also a lot of regulation that has to be taken care of as well. If the company the original poster is working for is not in that field, it should either make a serious and costly effort to get into this field if they're interested, or just acknowledge that other people are better suited for the job. Just like parent here, I think that is the only way to solve this problem.
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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.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Of course, if the air is guaranteed dry, then it's another situation entirely. Dry air can be any temperature above the minimum functioning temperature of the components, and everything'll be just fine. A warehouse keeping things that could get damaged from condensation or ice, for example, is going to be extremely careful to keep the moisture out. If that's the case, you don't need to repeat the process. Let the computer chill out.
Immersion methods won't work well if you have mechanical components, such as hard drives. You also have a major problem of the bearings freezing up. So, if these are "traditional" PCs with mechanical devices, you have to go for a different approach. In these sorts of cases, you really want to have the computer lagged to the hilt (no, I don't mean run slowly) and have some form of active homeostasis - a heat pump that can transfer heat in or out as needed, for example. Under most conditions, a very passive form of homeostasis is sufficient - have cold air or a cold fluid pass by hot components. That's fine, because heat won't generally flow against the gradient, so the temperature of the air/fluid is the minimum temperature the system can ever reach.
When you're varying the amount of heat you're generating, but the amount you're losing is fixed - particularly if the ambient external temperature is too cold for one or more components - then that is useless. The system will sometimes run too hot and sometimes too cold. That's not good. In those cases, what you want is somewhere you can dump extra heat you don't want when the system runs hot, and somewhere you can pipe that heat in from if the system starts getting too cold. Then you can always keep things just right.
The long and the short of it is this: It all depends on circumstances. Not all cold is created equal, nor are all machines the same.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
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.
-Tim Louden
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 problems. Like I said above, the only things that break are the fans, and they probably would have broken inside the house too (because of dust). But since it's cold the fans are next to useless anyway. My server + a three-disk RAID-5 pack have survived ~50C heat (next to no air circulation in that closet) and -36C winter. The only thing I've ever cared about is that if during the winter I take the server out of the closet, I make sure it warms up and dries properly before I put it back there. And I refuse to start the harddrives when they're frozen - so I take the server inside the house, warm it up, make sure it runs ok and then put it back.
So forget all comments about insulation, heaters, remote sensors etc etc - the people who wrote those comments haven't done sub-zero computing.
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 (iirc).
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
Man, I just heard about this incredible peice of equipment on New Scientist. It's called a "Heater." It has a coil and a fan and stuff. Not quite sure how it works, but I think for the amount of times a nearly always on computer will boot, it might be worth living dangerously and trying one out, in conjunction with one of those newfangled "Thermostat" things.
I have freaks! I did something right...
Use a Pentium 4. It will provide your computer with enough heat so that it will run at a good temperature, if the ambient temperature is below zero.
Yes, see here. Sorry, don't have the time to comment right now.
Non-Linux Penguins ?
Now try running that "heater" thingee on a remote site with no AC-mains supply, just a solar panel and batteries. Good luck with that.
but I know how to run Sub-Zero in a computer environment.
Forward - Down - Forward - low punch.
FINISH HIM !
Sub Zero Wins !
Not true. It will have low humidity, but not zero. However, if the air around the computer is heated from the computer itself, I would be surprised to see any condensation. Low humidity air being heated should be able to hold more water not less. Condensation happens from moisture in warm air coming into contact with cool or cold air. This would be the opposite of what is happening in the freezer. As someone else mentioned, different thermal expansion rates of the computer hardware is probably more of an issue than humidity.
Bottom line, shop for equipment built for the job. If you have a need for this now, it is a very, very good bet that someone has done the same or similar before. I'll guarantee that you aren't the first person to have a need to run computer equipment in low temperatures. You've heard this before, and now, once again: "Don't re-invent the wheel."
For example, in a past life, we needed a gas analyzer shed full of, well, gas analyzers (Gas Chromatography TCD/Mass Spec, associated remote computers, etc.) that would pull in and analyze gas from several process lines. It was basically an insulated hut that sat outside in what could be as low as minus 50 degree celcius temperatures (not counting the bullshit windchill people like to brag with). And yes, it had heaters in it to make sure a the inside temperature was at least around plus 5 degrees C. This is the first time we needed something like this, but yes, there were several suppliers with that kind of experience available who were able to provide bids for the work. Even though it was the first time for us, we weren't breaking new ground. :-)
-- I ignore anonymous replies to my comments and postings.
...be sure to install the Catalyst 6.8 drivers so the computer won't shut down if the graphics card measures negative temperatures.
No, I'm not kidding... ^_^
np: Yello - Ocean Club (Baby)
"I'm not anti-anything, I'm anti-everything, it fits better." - Sole
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..
---- Booth was a patriot ----
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? ;)
Willie...
There are plenty of blogs from Antarctica about people using standard PCs in very low temperatures who you can contact for practical experience if you need, but you're only in Alaska & Alberta territory. The silicon itself loves the low temperatures.
The two issues are insulation stiffening in the cold, and differential thermal expansion. Both of these cause commodity power supplies to be flaky in Antarctica, but I don't know how much power you'll be dissipating - are we talking full-sized PCs or little fanless embedded boxes? Wiring issues depend on how many wires you have, and what sort of motion or vibration they'll be exposed to. It boils down to, if you flex a piece of Cat-5 at low temperatures, you can crack the insulation and short it out. But if you can install it reasonably warm and not move it, you shouldn't have a problem.
Differential thermal expansion is a problem mostly when temperature cycling, turning equipment on and off. The fact that copper, silicon, ceramic, solder, and fiberglass have different coefficients of thermal expansion has an effect not unlike flexing the circuit board; components can pop right off.
However, as long as you ventilate (not, as others have suggested, insulate!) your equipment well, the temperature DIFFERENCE won't be any greater than at room temperature, and the stress likewise won't be any greater. Dissipating X watts will cause a rise of Y degrees over ambient, which is multiplied by a coefficient of thermal expansion of Z per degree. As long as you're dissipating X watts, the load on the freezer is the same whether your equipment is insulated or not, so there's zero benefit unless there's an alternate cooling path that doesn't go through the freezer's compressor.
You've seen the crazier overclockers pouring liquid nitrogen over generic low-budget PC hardware, so even equipment not specially designed for low temperatures can take temperatures way beyond what you're asking for.
As others have noted, condensation is only a problem when your computer is colder than the air aroud it; in this case, it's going to be the warmest thing in the room. Just keep it out of range of any warm humid gusts when the door is opened.
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?
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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://www.versalogic.com/Products/DS.asp?Product
Now, monitors can be a little trickier. To get that kind of operating tempurature in a display, you are either going heavy industrial equipment, or military, and you will pay a premium on those. If you don't need a display, or can get away with a small 4x40 LCD module or something, that would be a much better approach I think.
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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 devices; Diamond Systems 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. Industrial CompactFlash cards are a good choice here. Finally, put the works in a good enclosure. Diamond Systems makes a good one for their SBCs; TRI-M has a good generic PC/104 enclosure.Digital Electronic systems *usually* do just fine in the cold, even at -50C. Analog systems sometimes run into trouble because capacitors & resistors change value etc. You have to be careful about calibration issues here. Also mechanical systems, especially fans are prone to trouble. Disk drives do OK because they are hermetically sealed and no moisture can get inside. Moisture condensation is likely to be your biggest problem. Also, my experience with LCD displays is that they do not work well below freezing, so you may need to get some CRT monitors. A simpler soulution might be a dedicated data logger (Campbell Scientific mkes good ones).
Wrap the equipment in an inexpensive heating pad. As a field engineer working in inadequately heated lumber mills in Northern Canada, a heating pad kept the ink in the HP inkjet printers flowing and prevented condensation from forming in the disk drives. Not to mention it was a great way to keep your hands toasty between tests!
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.
Apocalypse Cancelled, Sorry, No Ticket Refunds
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 $5 worth of power a month in winter).
The wireless gear generates little heat itself (the wall-warts are probably hotter). Make sure you have a heating problem - the computers in the box might overheat in a -14F environment. You might need to instead rig a thermostat to a vent that would let in some of the cold air for cooling.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
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 rather than technical need) -- Unless, of course, you're expecting to store gigabytes of data on the warehouse acquisition computers (which strikes me as not a very good idea).
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
Change is bad.
I've installed computers in the outdoors, and what you want is something from http://www.campbellsci.ca/ such as a beautiful CR10X which has a temperature range of -25 to +50C or other models with extended ranges, such as -55 to +50C.
These things are great for weather stations, and have all the electronics for measuring temperature, among other things. They are a bit expensive, and not very fancy, but still great and indistructable.
You could also get a bunch of sheilded low-voltage pair cable, and make a 107 temperature probe ( http://www.campbellsci.ca/Catalogue/107.html see manual for electronics) from a bunch of high-quality resisters ordered elsewhere, and do the half-bridge resistance measurement outside of the cooled warehouse, but measure the end of the probe.
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 need improved moisture resistance for connectors and cables, if not the entire system. Besides condensation and frost issues, the word "freezer" suggests "food storage", which means wash-downs. Be sure to understand the client's expectations for such mundane issues, as well as the technical aspects.
>There is absolutly no reason to have your equipment in there.
Glad you know so much about the project.
Many single board computers also have ruggedized models which can operate in a wider range of temperatures. Often the ruggedized models can operate in from -40 C to +85 C or at least -25 C to +50 C. So use those. Most come with something useful like linux or QNX pre-installed. Many are designed for what you are describing and have many data ports.
You don't say in detail what types of data they will be collecting. But I'd try to keep as much equipment, especially power supplies, out of the chilled area as possible and have each unit run as many sensors as possible. The servers and workstations should definitely be out of the chilled area or at least in their own insulated locker. Going a step further, try thin clients if you need terminals in the cold area. No sense in adding extra heat where it's not wanted or needed.
Beta is broken and the link to classic doesn't work. Stop wasting our time or there won't be anybody left here.
the displays? I know that the lcd on my cell phone doesn't respond after being left in my car during the Minnesota winter, which gets as cold. Are CRT's acceptable in this cold environment? A suggestion - what if you made your server rack in an old deep freezer or refridgerator (not plugged in)? I know my deep freezer gets somewhere around that temp, and the outside DOESN'T feel cool to the touch. I assume that it the heat generated from the electronics would keep itself around typical room temp or higher, and you would have a nice sealed access door.
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.
There are a couple of good reasons to change your proposal, and both have to do with introducing heat sources into a frigid environment. Why run a computer in the freezer? And why send in humans to run it?
Keep the heat-producing logic units out of the fridge and in a controlled environment that is conducive to logic. Comfortable seating, air nicely dried and chilled, cigar in mouth and martini at the ready.
I've had some (physics lab) equipment operating at low temperatures, and
my coworkers have done it down to VERY low temperatures. The
problems are many and subtle.
First (as another poster mentioned) transistors (bipolar junction transistors) lose gain
at low temperatures, while MOS adds gain. Either is sufficient to cause problems
(the bipolar transistors lose drive capability and the MOSFETs oscillate at frequencies
you didn't think they could reach). Second, there are little wire connections that were
made at solder-melt temperatures and cooled to room temperature (with some
builtin strain). The further cooling to low temperatures, with applied currents and
possibly vibration, can cause mechanical stresses to go over the elastic limits.
'Storage Temperature" specifications on individual parts are usually going to tell you
something of the range that's permissible, and typically those specs bottom at -65 to -85 C.
A few old chips have lots of temperature variants; Z80s were available in 0 to 70C (S grade)
down to -55C to +125C (M grade), so some really simple computers can be had
that won't mind the temperatures you have in mind. Old-fashioned is good enough,
sometimes.
I had an odd failure in a liquid nitrogen dipstick processor (*) where the eventual resolution
was that the CMOS circuit would work fine in the bore of the liquid nitrogen dewar, but
its power supply kept blowing transistors. The CMOS conductance was extra high
because of the low temperatures, and the clock-transient during switching was high current,
enough to cause 'exploding wire' phenomenon in the pass transistor. Average currents
were very low (maybe half a milliamp) but the little short transients had such a rise-time
that they blew up internal wires (rated for 250 mA or more) by ultrasonic shockwave.
The wires inside the CMOS chip were in an epoxy package and that kept them stationary
so it was always the power transistor that failed, never the CMOS.
Temperature sensor ICs that have frequency output can be multiplexed with
grid wiring and diode+sensor at each crosspoint. That'd mean only 20 wires into the
cold box for 100 temperature sensors. You can run a few dozen wires into the cold
box, surely? Diodes, and most temp sensor chips, are cold-tolerant.
Even if your chips will take the temperature, it's possible that a BIOS won't like it. If the CPU has a temperature sensor, is -14 degrees gonna make it panic? Unless your computers are spec'ed for the temperature, you shouldn't assume they'll even TRY to work.
Pulling a computer component out for maintenance will practically guarantee
it gets condensation at first contact with warm moist air. Condensing moisture is not
kind to connectors and switches, and does violate most warranties; you can work around
this (put the cold component into a baggie with some dessicant, keep it shut for
a few hours with dry air as it warms up) but it severely complicates the maintenance
issue. And, the 'correct' procedure is unlikely to be the one the customer uses when
you're not around.
(*) The long story: Carol wanted Chuck home in the evenings, but Chuck's
experimental apparatus could only keep running if he refilled the cryogens at few-hours intervals on
multiple-day experiment runs. So we cobbled up a capacitive sensor for nitrogen level
using two coaxial stainless tubes, a 74HC14 Schmitt trigger to oscillate it, and frequency-
triggered relay driver to allow compressed gas to push more liquid N2 into the reservoir.
When it got to working, we retired the laboratory cot.
I'm a design engineer at a temperature monitoring company (not a sales guy, I asked 'em not to bug you) and could probably give you a suggestion or two for your wiring etc. (A sales guy saw your post and asked me "how Slashdot worked" so I told him I'd contact you.)
Of course, I think in terms of our devices - we have a 16-channel monitor that's rated for installation down to -40 C (-40 F) and isn't terribly expensive ($499, I think, but since I'm a tech guy I don't know for sure) plus $50 per probe. Max run on a probe is half a mile (2600' or so) over cat5 (or you can buy more expensive long probes.) If you use someone else's hardware, look for industrial-temperature rated hardware if the PCB is going to be inside the cooled area. Mechanical parts (e.g. hard drives) should be avoided at all costs.
If you have any more specific questions I'd be happy to answer, even if you don't use our hardware. Our stuff is all Ethernet interfaced, for an example look at:
For humans:
http://em1.sensatronics.com/
For computers:
http://em1.sensatronics.com/config/
http://em1.sensatronics.com/data/
XML for computers:
http://em1.sensatronics.com/xmlconfig/
http://em1.sensatronics.com/xmldata/
Perl scripts are available that grab data from the devices. Note that they don't log data (normally... there's an HTTP POST feature that does log up to 18 hours of data) but are designed to get the data into PC-land as quickly as possible. They run a tiny embedded OS, Linux is a bit heavyweight for cheap 256K flash hardware. (uCOS/2, not that it matters.)
--Drew Van Zandt
Hardware Engineer
Sensatronics LLC
http://sensatronics.com/
Hard drives and fans fail when really cold. To get around this panasonic makes a toughbook with a tempurature sensor, and no fans. The Sealed Hardened Toughbook 29 will not operate until up to tempurature. I support a number of Police cruisers in a cold climate. The toughbook solution works well. Another alternative is to buy solid state thin clients and run Terminal sessions back to your server of choice. I have not personally seen any thin clients setup in a cold environment....but it may be worth investigating.
"I myself am made entirely of flaws, stitched together with good intentions."
If you want to perform temperature measurements in a cold storage warehouse don't use PC's at all. Instead use an Adam 6018 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 sample applet included with the device only works under Java 1.3.0_04. The Adam technical help will not be able to tell you this. Your best bet is to use the MODBUS/TCP protocol to query the device. You don't have to know much about MODBUS/TCP nor industrial network protocols. Just use Ethereal while the sample Java applet is working and you will sniff the correct addresses, commands, etc. I'm not a programmer and I got a PHP Modbus/TCP class (with all documentation in French...which I don't speak) to call the device and display the correct temperature in about 5 minutes.
Also, the temperature is reported back in as a 16 bit integer (0-65535). 0 corresponds to whatever you set as the lowest limit for the thermocouple and 65535 corresponds to the highest. Everything in between is linear. Again, its like pulling teeth to get this information from the manufacturer.
Simple people talk of people, better people talk of events, great people talk of ideas.
The first thing I would do is build a test system and just run it in the cold environment sans any kind of help at all. Especially with a Netburst P4, computers generate so much heat that I doubt it'd get any colder than 40 degrees or so inside the case.
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