How is a PC effected in freezing cold?

[Colonal-Kohler]

I am looking at building a PC to use in my garage, and it's probably going to be on 24/7. Problem is it's a detached garage that is not heated or cooled, and I live in Ohio where winters get well below 0. Is leaving a PC running in that environment going to kill it, or even if it was off would be bad for it?

[DrMacintosh]

It will be fine unless you turn it on  when its freezing and this happens:

 

 

[SageOfSpice]

If it's running, it probably won't kill it. I'd imagine your largest issue would be any electrolytic capacitors, as I don't think they're rated for below 0 temps.

[EPPHO]

Just now, DrMacintosh said:

It will be fine unless you turn it on and this happens:

 

 

Yeah true, that's what i wanted to say.

 

If it's too cold don't turn it on.

[JeJaRaLa]

the only problem is condensation inside the case  that can kill your pc

 

[LogicalDrm]

Like said, since air is cooler than components, cold will condensate as water near hotter surfaces. You don't need much heat to get rid of issue. I would say 10-15C would be fine unless its some mining rig running at full load all the time.

[JacobFW]

Do NOT put any mechanical hard drives out there.  The cold will warp the metal and almost certainly kill it.  SSD's are kinda ok, but you should try to insulate them if possible.  The controller can that cold, but the NAND cells themselves will last longer if they're warmer (but not too warm).

 

As for the condensation non-issue.  This is NOT the same thing as a subzero cooler.  1)  The surface has to be cooler than the ambient air for condensation to occur.  2)  If it's below freezing, then there is no liquid/water vapor.  One of the driest places on earth are the polar regions, since, even though it's surrounded by snow and ice, all the H20 there is solid.  

[For Science!]

We used to have PCs running constantly in a 4 C cold room with no problems (although they weren't doing much in terms of load to be honest). The only real trouble was when we took it back out to room temperature, then it condensed a lot so we had to make sure it was really well dried. But in theory if its constantly cold and above frosting point, then it should be fine, but if below 0, i can't recommend it.