In article <11l9jlmns1jere5@corp.supernews.com>, John Corliss
<jcorliss@fake.invalid> wrote:

> My system is set up with two hard drives and I use XXCopy:
>
> http://www.xxcopy.com/index.htm
>
> to clone one to the other on demand. I do *not* use RAID because I want
> control over when a backup copy is made. Unfortunately, I recently fried
> my main hard drive and had to send it back.
>
> Yesterday, I received the replacement hard drive from Newegg.com and
> have installed it. Since I've now gone through two secondary hard drives
> in what I consider to be short order, it's time to figure out why this
> is happening. Kony (my thanks to you!) and somebody else (sorry, I can't
> find the thread now) suggested that I look into cooling the hard drives.
> This makes a lot of sense to me because they're mounted right on top of
> one another, and when I touch them after running the computer for a
> while, they're both rather warm - bordering on HOT.
>
> Time to cool those puppies.
>
> I've been looking at various fan additions and what I really want to do
> is to blow directly ONTO the hard drives in order to maximize heat
> removal. This, however, will blow dust onto the hard drives and as Kony
> mentioned, "while a drive is sealed, most have a filtered vent hole
> still." This means that dust still has a way into the drive, although
> it's a difficult path. Thus, I would think that it's better to suck air
> away from the drives rather than blow onto them.
>
> Mounting a hard drive in a fan unit that fits into a spare 5.25" bay is
> not an option, because I want to cool both hard drives. However, I'm
> thinking of additionally adding a 5.25" bay mounted case fan in the
> middle bay (I have three) to cool my two DVD drives and provide
> additional case ventilation.
>
> But back to the hard drives, I'd like to find something that will mount
> so as to suck the hot air right off of the hard drives and out of the
> case. I would prefer not to use something that will suck the heat off of
> the hard drives and distribute it into the case, but maybe that
> additional fan in the 5.25" empty bay will render that concern of no
> consequence. Any recommendations?
>
> TIA

If you look at this patent application, I don't think anything is
getting through that breather hole :-) The breather hole is only
intended for pressure equilization, when barometric pressure changes.

http://www.wipo.int/ipdl/IPDL-CIMAGE...EMENT_SET=DECL

Example of a commercial breather hole filter:
http://www.donaldson.com/en/diskdriv...ary/000610.pdf

Also, from an IBM disk manual:

"Do not cover the breather hole! Covering the
breather hole may result in loss of data."

I still don't understand why the pressure is so significant. If
you take a computer to Boulder Colorado, the air inside the HDA is
going to get thinner, so big deal ? I wonder if flexure of the
cover is the problem ?

http://www.storagereview.com/guide20...p/packAir.html

No matter how you move air over the disk, the air is a soup of
particles that are monstrous in size compared to the aperture on
the breather filter. A more dangerous situation, would be opening
a bottle of solvent next to the drive, as vapour phase is likely
to be a more effective poison than particulate (even if there is
a diffuser channel).

*******
I built a frame that fits over three 5.25" drive bays, and the
frame holds a fan. That is how the disk drives in one of my
computers get cooled. It pulls cool air from the outside over
the drives. Another of my computers has a fan mounted in front
of one of the drive cages, which performs the same function.

Here is an example of a module for a coolermaster CMstacker case.
It consists of a fan plus HD cage. Some other cases fasten the
fan to the case, and the cage is removable.

http://www.i-tech.com.au/products/item5641.asp

The two enemies of the hard drive, are heat and moisture. The
allowed temperature drops with increased humidity. At 60% R.H. you
are allowed about 35C. (IBM or Hitachi disk OEM manuals have curves
for allowed environmental conditions.) Now, if I am to believe that,
then how do people in tropical countries use these drives ?

http://www.hitachigst.com/tech/techl...Deskstar_7K250
"Deskstar 7K250 Specification v1.5 (Serial ATA)" - PDF pg.35
http://www.hitachigst.com/tech/techlib.nsf/techdocs/17351B59F3028F4486256D3D0065D995/$file/d7k250S_sp.pdf

Paul