[nzlug] Fans?!?

[Daniel Pittman]

cr <cr at orcon.net.nz> writes:
> On Wednesday 28 February 2007 08:32, Vik Olliver wrote:
>> On Wed, 2007-02-28 at 04:45 +1300, Nevyn wrote:
>
>> > Unfortunately the fileserver is in my room, and a 12cm fan is just
>> > way too noisy.
>>
>> There is the ultimate bodge: The use of a desk fan, fixed to a hole
>> cut in the case with a chassis nibbler...
>
> Or, of course, you can (specially if it's a tower case) just leave the
> side panels off completely, thus giving heaps of gentle flow-through
> ventilation for your drives, 

Actually, watch out for that.  Many cases are designed to work correctly
only if the side of the case, the drive bay covers and most of the PCI
slot covers are present.

Disrupting that airflow path can have significant effects; in the
specific case you suggest the effect is normally to *reduce* airflow
past the hard disks:

Normal design has an intake at the front of the case, toward the bottom,
where air is drawn in over the hard disks.  It then flows up past the
GPU and CPU, then out exhaust fans in the power supply and
(occasionally) on the back of the case.

Without the side panel in place air can be drawn in through the open
side of the case by the power supply fan, so you have less air motion
past the CPU and GPU -- and practically none, only convection movement,
over the hard disks.


This can nicely cook your hardware for you.  My server case, for
example, has close to fifteen degrees hard disk temperature difference
between the case closed and open, purely due to airflow changes.

Regards,
        Daniel

> and allowing a nice view of the motherboard (some of these things are
> almost works of industrial art, which is better than I can say for the
> stylists' ghastly efforts on many cases :) It also facilitates
> fiddling with boards and stuff....
>
> I've just felt my drives and they're barely warm to the touch.
>
> The CPU fan makes a bit of noise, of course.
>
> Umm, my tower case lives on a high shelf, which means it's fairly safe from 
> being accidentally kicked.    It might not be quite such a good idea for 
> floor-mounted tower cases   ;)
>
> cr
>
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