computers and cold temperatures[OT]

[Billie Walsh]

On 11/11/2011 12:21 PM, Doug wrote:
> On 11/11/2011 08:32 AM, Colin Law wrote:
>> On 11 November 2011 13:01, CJ Tres<ctres at grics.net> wrote:
>>> IS it a bad thing to have a computer operating, say, in a garage
>>> during the
>>> cold winters?
>>> I realize there is some discussion on running 24/7 due to heat/cold
>>> expansion/contractions but it this machine were running 24/7 during
>>> winter
>>> is there any reason to believe it would be detrimental to the comp?
>>
>> I had a PC running all last winter in a shed down to -14C capturing
>> video from a wildlife camera. Along with the Linksys wireless router,
>> configured as a wifi repeater, it worked perfectly, rather to my
>> surprise.
>>
>> I don't think there would be any doubt that operating in a more benign
>> environment would be more likely to make stuff last longer though.
>>
>> Colin
>>
> Most ICs are rated to operate down to 0°C, which is 32°F. Below that,
> it's a toss-up. Many years ago I designed a circuit with an op-amp that
> was rated (I discovered after the fact) at 0°C. At -15°C it stopped
> working! I had to replace it with a device with inferior specs, but that
> was rated to -40°C.
>
> What may save your bacon is the fact that the computer generates
> internal heat, and may get warm enough to keep everything happy,
> particularly if the fan(s) have thermostatic control.
>
> --doug
>

This is all very simplified.

Electrical conductors lose resistance as temperature drops. At a certain 
point they become "super conductors" [ 
http://en.wikipedia.org/wiki/Super_conductor ]. That is, their 
resistance drops to zero. Electronic devices rely on resistance in one 
way or another. If their resistance drops below a critical level they 
just become conductors and stop functioning in the manner they are designed.

Conversely, as electrical circuits heat up they have a higher 
resistance. This has negative effects on electronic circuitry. Circuits 
can generate even more heat due to the rise in temperature. Causing 
circuit failure.

In theory, the colder the better [ as long as the resistance factor 
doesn't change outside normal function ]. At colder temperatures 
computer circuits should function better and be faster.

If you want to put a computer in a very cold area it might be best to 
have some sort of thermostatic control of case fans to maintain some 
heat in the case.

-- 

"Democracy is two wolves and a lamb deciding what to have for dinner. 
Liberty is a well-armed lamb."     - Benjamin Franklin -

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