Air filter on hard drive

[Guest]

Does anyone know if the breather filter used by hard drives blocks
moisture as well as dust? If it doesn't, what keeps the internal
dissicant bag/filter from saturating quickly? Does heat from the hard
drive dry it out?

 

[Rod Speed]

Does anyone know if the breather filter used by
hard drives blocks moisture as well as dust?
Nope.

If it doesn't, what keeps the internal
dissicant bag/filter from saturating quickly?

Very little air moves thru that filter.

Does heat from the hard drive dry it out?

To some extent but the moisture cant get out.

 

[Lil' Dave]

Dessicant is meant for enclosed areas with stagnant air. Non-ventilated,
that is. Normally used for shipping items or when an item is not
anticipated use for a lengthy period of time.
Dave

 

[Guest]

Very little air moves thru that filter.

But doesn't moisture get into the bag simply through diffusion, which
occurs even while the drive is turned off?

 

[Rita Ä Berkowitz]

"Rod Speed" <[email protected]> wrote in message

But doesn't moisture get into the bag simply through diffusion, which
occurs even while the drive is turned off?

We've removed the OEM filters from all our drives and installed K&N Filters
in their place. Now we have a 20% increase in performance.



Rita

 

[Rod Speed]

But doesn't moisture get into the bag simply through diffusion,

What bag ? You dont get much moisture thru an
antistatic bag if thats the bad you are talking about.

 

[Jim Jones]

We've removed the OEM filters from all our drives and installed K&N Filters
in their place. Now we have a 20% increase in performance.

Even you should be able to manage a more viable troll than that, Bigotowitz.

 

[Guest]

Very little air moves thru that filter.

What bag ? You dont get much moisture thru an
antistatic bag if thats the bad you are talking about.

I mean the bag inside the hard drive that serves as both the filter to
catch the internal dust blown off by the platters and to absorb
moisture. I've seen it in old 5.25" drives, at least one 3.5" drive,
and in a picture of a 6.4G IBM Deskstar, always tucked into a pocket
molded into the aluminum and located just beyond the platter stack.

 

[Al Dykes]

But doesn't moisture get into the bag simply through diffusion, which
occurs even while the drive is turned off?

Maybe it does. So what. If it's like the silica bags that we get with
equipment all the time, it doesn't get dripping wet when it's sitting
on the shelf, exposed to all the air in the world.

There is no net airflow into the case. A little goes in and out,
depending on barometric pressure and the internal temperature. When
your disk is on (or off) all the time flow might be about zero.

 

[Al Dykes]

We've removed the OEM filters from all our drives and installed K&N Filters
in their place. Now we have a 20% increase in performance.



Rita

No smiley on that ?

 

[Rod Speed]

I mean the bag inside the hard drive that serves as both the filter to
catch the internal dust blown off by the platters and to absorb moisture.
I've seen it in old 5.25" drives, at least one 3.5" drive, and in a
picture of a 6.4G IBM Deskstar, always tucked into a pocket
molded into the aluminum and located just beyond the platter stack.

OK, but I now cant see the point of the comment about diffusion.

I meant that very little air moves thru the filter thats
on the hole between the inside and the outside of the
'sealed' chamber thats there to allow equalisation
between the inside and the outside.

 

[Guest]

Maybe it does. So what. If it's like the silica bags that we
get with equipment all the time, it doesn't get dripping wet
when it's sitting on the shelf, exposed to all the air in the world.

There is no net airflow into the case. A little goes in and out,
depending on barometric pressure and the internal temperature.

It seems that there would be a net diffusion of moisture into the
drive, assuming that it's not hermetically sealed and the silica gel
hasn't saturated.

 

[Rod Speed]

(e-mail address removed) (Al Dykes) wrote

It seems that there would be a net diffusion of moisture into the drive,
assuming that it's not hermetically sealed and the silica gel hasn't saturated.

Nope, because there is only a tiny hole in the 'sealed' chamber.

 

[Timothy Daniels]

Nope, because there is only a tiny hole in the 'sealed' chamber.

"Tiny" in this case would imply "slow", not "nope".

*TimDaniels*

 

[Timothy Daniels]

I meant that very little air moves thru the filter thats
on the hole between the inside and the outside of the
'sealed' chamber thats there to allow equalisation
between the inside and the outside.

Why must the gaseous pressure inside and outside
a HD casing be the same? If you took it up in an
airplane, would it explode if it weren't vented? If
the airplane came back down, would the casing
crumple? What if the airplane went up fast or lost
pressurization, would the "tiny" vent hole allow
air to pass through fast enough to prevent bulging?
Indeed, is there any restriction placed at all on a HD
regarding the rate of altitude change? (Check out
the Maxtor design specification manual that is
downloadable as a .pdf file -


http://www.maxtor.com/en/documentation/manuals/diamondmax_plus_9_manual.pdf -
and look at the section in chapter 4 on Environmental Limits.)
I don't think you've thought the whole thing through.

*TimDaniels*

 

[Rod Speed]

Rod Speed wrote

Why must the gaseous pressure inside
and outside a HD casing be the same?

Its not essential, just done that way to be
more viable over the long haul, particularly
with shipping by air in unpressurised holds etc.

If you took it up in an airplane, would it explode if it weren't vented?

Nope, but it would move significant air thru the bearing
and its better to have a small hole with a filter instead.

If the airplane came back down, would the casing crumple?

Nope, but again, its better to have the air move thru
the small hole with a filter on it than thru the bearing.

What if the airplane went up fast or lost pressurization,
would the "tiny" vent hole allow air to pass through fast
enough to prevent bulging?

It wouldnt bulge significantly even with no
hole. Its just better to have the flow thru
the filtered hole than thru the bearing.

Indeed, is there any restriction placed at all
on a HD regarding the rate of altitude change?
(Check out the Maxtor design specification
manual that is downloadable as a .pdf file -
http://www.maxtor.com/en/documentation/manuals/diamondmax_plus_9_manual.pdf -
and look at the section in chapter 4 on Environmental Limits.)

Not relevant to why there is a filtered hole.

I don't think you've thought the whole thing through.

Not a shred of evidence that you are actually
capable of grasping even the simplest concepts.

 

[Rod Speed]

Rod Speed wrote

"Tiny" in this case would imply "slow", not "nope".

Wrong. As always.

What moves thru that hole aint due to diffusion, its due
to a pressure difference between the inside and outside.

 

[Timothy Daniels]

Wrong. As always.
What moves thru that hole aint due to diffusion, its due
to a pressure difference between the inside and outside.

The net transport of gas molecules, whether it is called
"diffusion" or "flow", is due to pressure differential (called
a "partial pressure" in the case of a specific type of gas in
the presence of other gases), and the rate of flow through
a hole is a function of the cross section of the hole. That
means "tiny hole - slow flow".

*TimDaniels*

 

[Rod Speed]

Rod Speed wrote

The net transport of gas molecules,
whether it is called "diffusion" or "flow",

The word diffusion has a quite specific
meaning, you silly little posturing wanker.

Reams of your desperate attempt to bullshit
your way out of your predicament that fools
absolutely no one at all, flushed where it belongs.

 

[dg]

Was that a measured 20% increase in performance or a "seat of the pants"
test? Aren't you worried about larger particles of dust getting into the
drive with that increased flow? Ha Ha.

--Dan