Power supply fan airflow direction

Halfgaar Babbled on and on and on about:

Wheat Muncher wrote:

I would have thought the same, until I tried it. It actually caused
my case temp to rise a good 10 degrees celcius, which in turn made
everything a bit hotter. As it stands also, AMD's need the PSU to
draw the hot air off of the heatsink in order to keep the cooling
efficient.

Is that a fact? Hmm. Well, what about when you CPU is watercooled, as
is the case with mine. The heat of the CPU is cooled by the radiator
in the front-bottom of the case.

But keeping this in mind, I think I need to build in some kind of
extra fan at the top-back of the case, because the PSU is cooled with
a papst 12 db, which hardly moves any air (see my reply to Ken's
message as well).

Halfgaar

Water cooled? Cool. how is that working out? I have seen and read so much
about, but I am a little leary to try it.
As for building an extra cooling setup, here is one thing I have done:
First, if you can find an alternate fan that will match the size of
you're Papst, then change it, right away, and make sure the airflow is in
the right direction. Sometimes I have found that a little extra noise is
well worth it.
Also, on either the bottom or face of the PSU, where the grill is for the
intake inside the case, silicone/crazy glue/ JB weld a small fan blowing
air into the PSU. Just a thought.

--
Wheaty...


Gimme the ball... gimme the ball, gimme the ball, gimme, gimme, gimme.

kony wrote:

A passively cooled system needs air vents, but a actively (fan-cooled)
system shouldn't have any except in very strategically located spots,
and then only if the case is designed so that internal pressurization
forces air out those vents. Many systems/cases are designed just the
opposite, with a slightl depressurization inside the case, reducing
effective cooling of the fans, and pulling in dirt though every tiny
crack, crevace, and optical, floppy drive.

That's something I've noticed with my other computers, that air is sucked in
through the floppy drive and the like. I think one of the reasons why this
is not happening with this case is that is is packed with cables. It didn't
even do that with the original fan in the PSU.

Having air vents in top would result in the power supply pulling in
outside air, which again, would be good for the power supply, but
reduce system cooling. This is another area in which many poorly
designed cases are causing problems, drawing air in through vents
directly above and below the PSU, instead of the front face of the
case.

If I had your system I'd put a second fan on the power supply, blowing
in, perhaps slightly higher RPM than that Pabst you're already
using... the internal PSU fan's noise should be less noticeable than
an exhaust fan.

I'll experiment with that. BTW, do you mean by a fan with a slightly higher
RPM than the Papst that the intake fan should blow harder than the
"outtake" fan, or just that the Papst doesn't blow hard enough?

I'm testing an extra exhaust fan now (see my reply to Wheat Muncher's
message), inspite of what you said, the PSU seems cooler now. The case
definately is, but not enough (4-5 degrees C).

Halfgaar
--
To send email, change nospam.com into yahoo.com.

w_tom wrote:

Before anyone can make an accurate conclusion, you must
first supply basic facts. 80 mm Papst fan that only does 12
dB noise has minimal CFM - only about 20. Without fundamental
numbers, then every response is simply speculation. To
determine what is and is not sufficient airflow for a chassis
requires such basic facts such as fan's CFM, watts consumed by
system (which is be a number less than the power supply's
rating), and other such data.

Doing a rough calculation for a small system puts the fan on
edge of acceptable. More than enough for a computer in a 70
degree room. But your system must be sufficient for a 100
degree F room. Most systems are sufficient with a 30 or 40
CFM airflow. Yours is lower - unless of course that fan is
not the 12 dB version.

But we know this much. Responses are only speculation until
you first provide some fundamental technical numbers. So far,
insufficient data has been provided to properly answer
original point of your original question. Is fan direction or
CFM sufficient? We don't even know what the fan is? How can
anyone properly answer such as question? Is power supply too
hot? Your hand calls hot what a semiconductor calls
paradise. How hot is hot - a number is required?

My simple question caused a lot of discussion, that what not my intention.
Answers like "depends on the system" or "It was attempted once, but not
continued, because ....." was what I was expecting. I don't need to know
how my system specificly would react to it. I would have tried it if that's
what I wanted to know.

On Tue, 24 Jun 2003 00:35:53 +0200, Halfgaar
wrote:

snip


I'll experiment with that. BTW, do you mean by a fan with a slightly higher
RPM than the Papst that the intake fan should blow harder than the
"outtake" fan, or just that the Papst doesn't blow hard enough?

I mean both, that a Papst fan with that low of a noise rating can
safely be assumed to produce too little airflow for heat removal in a
PSU producing significant heat as it will in a modern
(higher-performance) system.

Perhaps only changing the Pabst fan to a higher CFM fan would work,
but the rear fan in a PSU, being at the wall of the casing blowing
out, will cause more noise to escape the case. A lower-noise solution
would be to keep that fan but add a second fan, blowing into the PSU.
It's possible that another similar (low-airflow) Pabst fan would be
sufficient addt'l airflow, but only you can make that determination
and decide how hot you want to allow the PSU to be.


I'm testing an extra exhaust fan now (see my reply to Wheat Muncher's
message), inspite of what you said, the PSU seems cooler now. The case
definately is, but not enough (4-5 degrees C).

Halfgaar

Where are you taking your case reading? If it's the motherboard's
integrated sensor, the reading you get is from a chip, often the
southbridge, and is not directly related to actual ambient case temps,
can largely be ignored. The Southbridge will be fine running at ~45C,
but consider the other components like the HDDs, effecitveness of the
CPU heatsink, motherboard power supply area (capacitors temp).


Dave

Water cooled? Cool. how is that working out? I have seen and read so
much
about, but I am a little leary to try it.

It's working out great, but I would be better if I had a bigtower. If I
had
a bigtower, I could mount a 120mm fan an the top, let it run very slowly
and create a lot of airflow that way while still being silent.
My setup still requires a lot of tweaking. I've used silver paste against
Tomshardware's and Innovatek's (manufacturer) recommendations for example.

Check out http://www.tomshardware.com/howto/20020701/index.html. That's
the
watercooling system I use. Except that I only cool the CPU and GPU.
There's
also a divx movie you can download which shows how to build a watercooling
system.
And should you hastely decide to build a watercooling setup, make sure you
put anitcorrosion liquid in the water. Tomshardware doesn't mention
anything about it, which puzzles me. Look on forums and the like for what
happens when you use aluminium and copper in the same setup without
corrosion protection...

If I recall my Physics correctly, it is only a problem if you use different
metals in your system. An all Al or all Cu system shouldn't cause problems
and multi-metal systems should be avoided if possible.

Halfgaar Babbled on and on and on about:

Wheat Muncher wrote:

Water cooled? Cool. how is that working out? I have seen and read so
much about, but I am a little leary to try it.

It's working out great, but I would be better if I had a bigtower. If
I had a bigtower, I could mount a 120mm fan an the top, let it run
very slowly and create a lot of airflow that way while still being
silent. My setup still requires a lot of tweaking. I've used silver
paste against Tomshardware's and Innovatek's (manufacturer)
recommendations for example.

Check out http://www.tomshardware.com/howto/20020701/index.html.
That's the watercooling system I use. Except that I only cool the CPU
and GPU. There's also a divx movie you can download which shows how to
build a watercooling system.
And should you hastely decide to build a watercooling setup, make sure
you put anitcorrosion liquid in the water. Tomshardware doesn't
mention anything about it, which puzzles me. Look on forums and the
like for what happens when you use aluminium and copper in the same
setup without corrosion protection...

As for building an extra cooling setup, here is one thing I have
done: First, if you can find an alternate fan that will match the
size of you're Papst, then change it, right away, and make sure the
airflow is in the right direction. Sometimes I have found that a
little extra noise is well worth it.

Well, the thing is, I changed the original fan with this Papst . The
original one makes a whole lot of racket. Maybe I should try an
Enermax or something similair.

Also, on either the bottom or face of the PSU, where the grill is for
the intake inside the case, silicone/crazy glue/ JB weld a small fan
blowing air into the PSU. Just a thought.

When the cover of my case is off, the PSU stays luke-warm, so I think
I have to find some other way of removing the hot air. I'm
experimenting with a small Pentium-fan at the back at the moment. I
mounted it to a grill and covered all the holes of the grill not
covered by the fan. The case stays cooler, but I need a fanduct
because the fan being so close to the grill gives a lot of turbulence
and therefore noise.

Halfgaar

Thanks. I'll check it out.
Seen the two (aluminum and copper) used together in cheap assed poorly
repaired radiators back in my wrench head days. gets pretty ugly.

--
Wheaty...


Gimme the ball... gimme the ball, gimme the ball, gimme, gimme, gimme.

CK Babbled on and on and on about:

Water cooled? Cool. how is that working out? I have seen and read
so
much
about, but I am a little leary to try it.

It's working out great, but I would be better if I had a bigtower. If
I
had
a bigtower, I could mount a 120mm fan an the top, let it run very
slowly and create a lot of airflow that way while still being silent.
My setup still requires a lot of tweaking. I've used silver paste
against Tomshardware's and Innovatek's (manufacturer) recommendations
for example.

Check out http://www.tomshardware.com/howto/20020701/index.html.
That's
the
watercooling system I use. Except that I only cool the CPU and GPU.
There's
also a divx movie you can download which shows how to build a
watercooling system.
And should you hastely decide to build a watercooling setup, make
sure you put anitcorrosion liquid in the water. Tomshardware doesn't
mention anything about it, which puzzles me. Look on forums and the
like for what happens when you use aluminium and copper in the same
setup without corrosion protection...

If I recall my Physics correctly, it is only a problem if you use
different metals in your system. An all Al or all Cu system shouldn't
cause problems and multi-metal systems should be avoided if possible.




But corrosion is a boon of copper. Look inside you're radiator of you're
car for example. If you have an older model, the core is probably copper
( a good thing) but the corrosion that builds up is horrible. They are
aptly named "Tin Worms" because they are just that.... little worm like
chunks that resemble tin. Once this starts, you had better believe that a
rupture is soon to follow.

--
Wheaty...


Gimme the ball... gimme the ball, gimme the ball, gimme, gimme, gimme.

CBFalconer Babbled on and on and on about:

CK wrote:

... snip ...

And should you hastely decide to build a watercooling setup,
make sure you put anitcorrosion liquid in the water.
Tomshardware doesn't mention anything about it, which puzzles
me. Look on forums and the like for what happens when you use
aluminium and copper in the same setup without corrosion
protection...

If I recall my Physics correctly, it is only a problem if you
use different metals in your system. An all Al or all Cu system
shouldn't cause problems and multi-metal systems should be
avoided if possible.

And don't build things out of mating threaded aluminum parts.
Those will inevitably sieze and need to be chopped up to separate.


Thanks for the heads up. I am actually thinking of using a braided
hydraulic tubing joined to small copper tubing at the heat points. The
braided tubing is high stress, so I shouldn't have trouble with it, and
it is coated inside for corrosion. I have used it before in cooling
setups for my oil cooler. Tough stuff. Might have a good use for it now.
i am going to build my own radiator inside to make the best use of a
MASSIVE case, so the airflow won't be an issue and I need an excuse to
play around with my new rig. I have a small duct job I am working on that
will run outside for fresh air, then into a filter to keep out the
critters. I just have to figure out a way to construct a proper heatsink
for the whole works, and I'm laughing. Might get the local welding guru
to melt down a bit of copper for me to make something out of.

--
Wheaty...


Gimme the ball... gimme the ball, gimme the ball, gimme, gimme, gimme.

CK wrote:

If I recall my Physics correctly, it is only a problem if you use
different metals in your system. An all Al or all Cu system shouldn't
cause problems and multi-metal systems should be avoided if possible.

Using one kind of metal usually prevents corrosion, true. But using
destilled water with corrosion protection is a must, and it improves heat
tranfer as well.

Halfgaar
--
To send email, change nospam.com into yahoo.com.

kony wrote:

Where are you taking your case reading? If it's the motherboard's
integrated sensor, the reading you get is from a chip, often the
southbridge, and is not directly related to actual ambient case temps,
can largely be ignored. The Southbridge will be fine running at ~45C,
but consider the other components like the HDDs, effecitveness of the
CPU heatsink, motherboard power supply area (capacitors temp).

The motherboards sensor, that right. I'm not sure where it is located, I'm
running a topic on it on a MSI group . I don't think it's the southbridge
temp, because my linux sensor tools can read a third sensor which is called
the southbridge, but it is normally disabled because it mostly gives bogus
readings. Someone on the MSI group said that on the K7T-Turbo2, the sensor
is below the AGP. I have a K7T-Turbo.

BTW:
HDD Temperature_Celsius 39
CPU Temp: +41.7°C
Sys Temp: +32.2°C

As I said to my reply to your other message, I made some changes. This is
the exact result. It' the result from hours of mostly being idle.
Unfortunatly, I don't know the temp at the top of the case.

Halfgaar
--
To send email, change nospam.com into yahoo.com.