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I have a CNC (a computer-controlled milling machine) in my garage. The garage is not heated, and the temperature goes down to -25°C (-13°F) some days in January. If I keep my computer, an old desktop, on all the time, could the low temperatures cause problems or damage it? No drastic temperature changes occur in my garage; it's just that I never heat it, so it falls to the outside temperature.

I think cold components in hot environments can create condensation, because hot environments have higher humidity and cause condensation on cold objects. I don't think any similar effects affect hot components in cold environments, but I'm not sure.

In short, is it okay to put a computer in a really cold (below freezing point) environment for a long time?

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Check the documentation for your pc and see if it lists a safe operating temperature range. – Mitch Jan 17 '12 at 20:47
@Lord Torgamus Thanks for corrections. Sorry for my bad english , it's not my primary language. – Jean-Francois Gallant Jan 18 '12 at 13:27
up vote 6 down vote accepted


There are several issues with operation of electronic equipment in low temperatures:

  1. Sudden change of temperature causes mechanical stress as components thaw and freeze again repeatedly. This can cause electrical contacts to weaken, heatsinks to work loose, etc.

  2. Some components simply do not work or perform poorly in low temperature: electrolytic capacitors and other components change their properties; LCDs simply would not work in sub-zero temperatures, etc. Wikipedia says that:

    Additionally, low temperature is a problem for most aluminum capacitors: for most types, capacitance falls off rapidly below room temperature while dissipation factor can be ten times higher at −25 °C than at 25 °C

Military-grade laptops cost a fortune for a reason... This being said, I have an old computer in my own unheated garage, and it survived occasional use in Canadian winter for two years without a problem. I keep its cover removed to lessen a chance of condensation, don't know if it is feasible for you since you drive a CNC with it (I use it for 3D printer so dust is not an issue).

Some say it's better to keep the cover off, so there is no sharp temperature change when the computer is turned on, some say it's better to keep the cover, so the internal components heat up a bit. I know that some Wi-Fi routers designed to work outdoors are actually heated...


I think LCD minimum storage temperature is usually above -25C, that means it can cause permanent damage (but check your manual). Otherwise computer should be ok, as long as you thaw it gradually to prevent condensation.

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I run it in my old garage two years ago at 5C in the winter. At this temperature I got no problem. But now I buy a new house with unheated garage. Run it uncover can be a problem for the dust yes. When you said "occasional use" it's because you not always keep it on ? – Jean-Francois Gallant Jan 17 '12 at 21:25
@Jean-FrancoisGallant: Yes, I turn it on only when I need it. Also, updated about the cover... – haimg Jan 17 '12 at 21:32

The hard drives "breathe" more under these conditions if the drive is allowed to go through warming and cooling cycles. In the Pacific Northwest you can end up with moisture condensing out inside the drive housing. We keep computers running 24/7 inside a cabinet where they can keep it relatively warm. Lower temperatures hopefully alleviate this kind of thing with less moisture being in the air.

Also with the new lead-free solders, surface mount chips, the high tin content can lead to problems under extreme cold. It actually deteriorates. We had the cold pop a few chips on one of our HP printers controller causing it to be warrantied. The service tech told us that it was due to the lead-free solder having less flexibility.

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Few bits of information.

  1. I have seen company that produced military/industry grade PC components. .. what they did is they used commercial grade components and tested whole equipment in fridges before selling them as military.

  2. I think it might be safe to keep the PC running if the temperature in the case does not got below 10C.
    Certainly, I would not try to power up the PC under 5C.
    Check temperature reading of your mobo's chipset if it is 10C then you are OK.
    For very cold environments in my project I added additional circuit to keep temperature at 10C at least.
    The simplified version of it would be like this:

    • a circuit of thermostat coupled with car mirror heater(s) connected to 12V line of your power supply.
    • PC to be kept in its case to which the heater is attached (inside of course). All fans should be in smart mode (run at low speed in cold temperature), which is now standard.

Note: There should be no risk of humidity as long as your PC's temperature is ca 4 degrees above environment's one.

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Some people on forum have the idea to put a 10-15watts lightbulb in the case with a termostat to keep the case warm. I don't read about someone try it. – Jean-Francois Gallant Jan 18 '12 at 13:10

Low temperatures themselves are not a problem, it is when they are combined with humidity that you'll start to have issues.

Computers should generally function very well in low temperature environments, but when there is moisture in the air, and that moisture builds up as ice or condensation on the computer due to the temperature differential between the computer components and the surrounding air, the computer will be at high risk for electrical failure.

So, find some way to keep the air in your garage dry and you'll have no issues whatsoever.

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If you put that computer inside a small box (cardboard would be fine) for the winter, and never shut it off, it should be fine. The biggest issue you'll run into is solder joints breaking from repeated heating/cooling, which won't be an issue if you leave the computer on. The box should keep it at a reasonable operating temperature.

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