On Wed, 19 Oct 2005 04:54:17 -0700, John Corliss
<jcorliss@fake.invalid> wrote:


>> Why? What case?
>
>Sorry, not sure what you mean by "what case?". In any event, I was
>referring to cutting a hole in the tower's side panel directly in line
>with the location of the hard drives.

I mean, what computer system case is this you are referring
to?

The typical case does not need holes in the sides of the
rack nor a fan pointed at it. Usually it is only necessary
to have ample intake area in front of the rack. "Typical"
and "usually" are of course not always true, there are some
odd cases out there. Installing such a side-panel fan also
has a liklihood to have a very high noise to flow (flow
actually through the rack itself) ratio.


>
>> That may have less benefit than you think.
>
>Not if the fan is one inch or less from and blowing directly across the
>hard drives, as will be the situation with my setup.

That's partly why it's such a noisey alternative. Holes are
but a minor flow, the typical front-mounted fan is bound to
move more air through the inside of the drive rack, enough
to make a side-fan in that location a bit redundant and
unnecessary with a fan fan in place. Since we don't know
the particulars of the case, that could vary if it were an
unusual design.

>Additional exhaust
>from the case will be assisted by a triple fan setup in the one
>remaining 5.25" bay.

Those also tend to be noisey unless undervolted, and often
short-lived if only 10mm thick fans.

>Operational temp range for the Seagate is 0° to
>60°C (32° to 140°F). For the Deskstar, it's 5 to 55° C (41° to 131°F).

Ok, but I wouldn't count on those for optimal lifespan as
the measurement ability of the drive depends on only a
measurement of one point inside one chip.


>
>> The typical solution, to have large passive intake vent or a
>> fan, in front of the whole rack such that the vast majority
>> of case intake is pulled through that rack, is quite
>> sufficient for cooling the drives.
>
>There are vent holes in front of the drives in my case behind the
>faceplate. However, obviously they're not doing the job adequately.

That is far too common a problem, with the ideal being to
cut out a larger area before building into the case. I can
see that some people might prefer to add a hole to side
panel if the system were already built, to avoid having to
disassemble it to control and remove metal particles formed
during cutting or drilling, though if you're going to be
drilling into the rack anyway you aren't necessarily
avoiding this situation.



>
>> While they need airflow
>> for cooling, they are not hard to cool given some space
>> between each in the rack.
>
>And therein lies my problem. That plastic cage I described is situated
>directly below the hard drives in the front of the case and restricts
>the amount I can lower the bottom-most drive to only an additional inch.

The cage just snaps in... might have a screw or two holding
it. There's no reason to leave it in if you aren't putting
a fan into it or using the speaker. Actually even if you
wanted a fan in that location it would do better to cut out
the appropriate sized hole into the case front wall. That
will tend to increase flow from such a fan by quite a bit.


>However, that should be sufficient to improve airflow. That lowering
>will be accomplished by fabirication of an extension to the hard drive
>cage. I don't know *why* it was built so that the drives are mounted
>only 1/8" apart. As I said in another post, it's just bad engineering on
>somebody's part.

It was engineered to provide the most drive positions on
it's paper spec without using more metal. It was also most
likely designed during an era when drives didn't produce as
much heat. Case manufacturers really don't care much about
how well their case cools, even when they add fans they do
so more as a *selling point* kind of feature towards
marketing, rather than an engineered solution for more
cooling. Apathy on their part, they don't care if your
parts bake.


>
>>> What I don't understand about my case is that there's some kind of
>>> square plastic cage that's 3" deep by 4.25" tall by 3.5" wide and it's
>>> located in the front at the bottom, snapped onto a ventilated metal
>>> portion of the case. There is a sensor of some kind in the cage and it
>>> has two wires going to it. I think this is supposed to be a housing for
>>> an optional case fan that I foolishly didn't order with the system.
>>
>> Standard front-case fan configuration, and the "sensor" is a
>> speaker, perhaps better called a buzzer since it's tonal
>> range is rather small. If your motherboard has an integral
>> speaker, you don't need it.
>
>I'll be hornswoggled. Thanks for the explanation. However, I don't see
>how a fan would need it. The rear fan is attached directly to the metal
>back of the case and I see no reason why the front one would need that
>plastic cage around it.

Rear fan can be attached with side-panel off, front fan
would require pulling off front bezel too which is more
work. Plus it incorporated the card-edge slots (usually),
and held the speaker. It was just a cheap multifunction
bracket that isn't used as often today because it was
sub-optimal for fans, and of course it costs more to have it
than omit it in a design.



>My intention is not to mount a fan in it though. Since heat rises *and*
>since I want additional cooling of my DVD drives, this unit or one like
>it looks to be what I want for that purpose:


The ideal would be to cut out a 92mm fan hole behind it, and
add another 4 position drive bay to the case right behind
it. 4 position so you can space out the drives. It's
possible to fab your own bay out of metal sheeting, but if
you're not used to doing metalwork it's probably not time or
cost-effective.


>
> http://www.casecooler.com/514slothardr.html
>
>As for cooling the hard drives, either my idea (side cover mounted fan
>and additional holes in hard drive or this unit:


Above linked fan bay cooler is better than some because it
has the 25mm thick fans instead of 10-15mm. Even so, they
show 6500 RPM per fan, it's going to be a little loud. I
suggest undervolting it quite a bit, 7V or lower. That will
also improve it's lifespan.


>
>
> http://proline.com/tech/stacker/
>
>will work. The Stacker unit though, would place the drives too far to
>the rear unless I remove the plactic fan cage.
>
>For the time being, I'm running my system with the side cover off and a
>desk fan blowing on it lightly. Monitored temps are definitely lower.

The stacker also uses less effective thin fans. The
time-tested ideal is still to have a 80+mm fan mounted in
front of the drive bay. If your bay is short and doesnt'
allow the fan frame internal to the metal wall of the
chassis, it might be possible to mount it externally behind
the front bezel, if the bezel is deep enough. I wouldn't go
below 15-20mm thick fans towards that end though.

It's not that the other various cooling solutions won't
work, but they do tend to be noisier and shorter-lived.