Fan differences?

[Tai Tze Hou \(Alvin\)]

What is the difference between sleaves fan and ball bearing fans?

thanks!

 

[Mike Walsh]

Sleave bearings are cheap. Ball bearings are reliable.

 

[Halfgaar]

What is the difference between sleaves fan and ball bearing fans?

thanks!

To be more precise, sleeve's are metal surfaces (with oil between them)
which slide over eachother. A ball bearing is two metal cylinders (one
small one which fits in a lager one) with balls between them. The latter,
obviously, is a better design. But, suprisingly, very-low-noise fans are
mostly sleeve's.

Halfgaar

 

[DaveW]

Ball bearing fans are heavier duty and last much longer.

 

[Lane Lewis]

What is the difference between sleaves fan and ball bearing fans?

thanks!

Never ever put a ball bearing fan in a PC

When it comes to small fans, sleeve bearings are the best. Ball bearings are
much more useful in larger motors.

The trick is buying quality sleeve bearing fans as many on the market
are just junk.

Try Panasonic Panaflo or Papst fans, they cost more than ball bearing fans
but will last much longer and run much quieter.

http://www.directron.com/papst.html

http://www.directron.com/panaflo.html

http://www.casecooler.com/vanstealquie.html

Lane

 

[kony]

Never ever put a ball bearing fan in a PC

That's a bit of an overstatement, isn't it?

Sleeve-bearing fans should NEVER be used in any application calling
for non-vertical mounting, and even the best sleeve-bearing fans
aren't suited for long-term use in high-heat, like a PSU exhaust. By
long-term, I mean the life of the power supply, which could be a dozen
years.

When it comes to small fans, sleeve bearings are the best. Ball bearings are
much more useful in larger motors.

Here is where I strongly disagree. Look at all the video card fans
and northbridges that fail because they're sleeve-bearing. Replaced
with ball-bearing fans, the user can expect 300% or longer lifespan.

It is not enough to relube the smallest of fans, their bearings are
significantly worn by the time the typical user notices anything is
wrong.

The trick is buying quality sleeve bearing fans as many on the market
are just junk.

Try Panasonic Panaflo or Papst fans, they cost more than ball bearing fans
but will last much longer and run much quieter.

Agreed, those two are great sleeve-bearing fans. For vertical mount,
any use other than tiny fans, or high-heat, either of those are very
good choices. On the other hand, Ball-bearing fans can be barely
louder, the difference can be slight enough to be unnoticable, and
narrowing yourself to only the above two fans will usually result in
paying a lot more per fan.


Dave

 

[ric]

Never ever put a ball bearing fan in a PC

When it comes to small fans, sleeve bearings are the best. Ball bearings are
much more useful in larger motors.

Horse pucky!

A ball bearing fan is better ANYWHERE that will be exposed to increased
temperature, like a PC exhaust fan or a PC PSU fan.

I have removed enough frozen and sticky 80mm sleeve bearing fans to
cover the walls of my house. I rarely (or never) encounter a failed
ball bearing fan.

I notice you didn't mention *why* one should never put a ball bearing fan
into a PC. Well? Why not?

 

[ric]

Agreed, those two are great sleeve-bearing fans. For vertical mount,
any use other than tiny fans, or high-heat, either of those are very
good choices. On the other hand, Ball-bearing fans can be barely
louder, the difference can be slight enough to be unnoticable, and
narrowing yourself to only the above two fans will usually result in
paying a lot more per fan.

And he completely ignores the fact that Papst (ebm) makes both ball bearing
and Sintec sleeve bearing 60, 80 and 92 mm fans, and the ball bearing fans
have longer MTBF (L10 life) than the sleeve bearing fans.

 

[Lane Lewis]

That's a bit of an overstatement, isn't it?

No there's no reason to.

Sleeve-bearing fans should NEVER be used in any application calling
for non-vertical mounting, and even the best sleeve-bearing fans
aren't suited for long-term use in high-heat, like a PSU exhaust. By
long-term, I mean the life of the power supply, which could be a dozen
years.

A quality sleeve bearing fan will last a dozen years. even in a PSU, even
horizonally mounted. Where did you get that "NEVER" from :O)

Here is where I strongly disagree. Look at all the video card fans
and northbridges that fail because they're sleeve-bearing. Replaced
with ball-bearing fans, the user can expect 300% or longer lifespan.

Cheap fans fail not high quality ones.

It is not enough to relube the smallest of fans, their bearings are
significantly worn by the time the typical user notices anything is
wrong.

Cheap fans yes. They can make sleeve bearing fans last twenty years if they
want to but most manufactures just buy cheap ones. The problem is not in the
design as it is in the cheap materials used, such as the quality of the oil
and the material of the bearing itself. Most manufactures buy low temp oil
and use a low quality brass alloy for the bearing.

Agreed, those two are great sleeve-bearing fans. For vertical mount,
any use other than tiny fans, or high-heat, either of those are very
good choices. On the other hand, Ball-bearing fans can be barely
louder, the difference can be slight enough to be unnoticable, and
narrowing yourself to only the above two fans will usually result in
paying a lot more per fan.

Ball bearing fans are reasonably quiet when you first install them and then
unlike a sleeve bearing fan get progressively louder as they wear, negating
the small difference in mtbf since they have to be replaced due to noise
anyway.

Sleeve bearing fans got a bad rap due to the large number of failures of
low quality fans. I recently pulled a panaflo from a PSU that was in a IBM
486 Valuepoint that cost $5000 at the time (94). It was still working
perfectly.

The only advantage of BB fans is noise. Usually before they quit all
together they will make one heck of a racket warning the user to replace it.

Lane

 

[Lane Lewis]

And he completely ignores the fact that Papst (ebm) makes both ball bearing
and Sintec sleeve bearing 60, 80 and 92 mm fans, and the ball bearing fans
have longer MTBF (L10 life) than the sleeve bearing fans.

Didn't ignore anything, Ball bearing fans do have their applications but a
PC is not one of them due to the noise factor.

Lane

 

[Lane Lewis]

Horse pucky!

A ball bearing fan is better ANYWHERE that will be exposed to increased
temperature, like a PC exhaust fan or a PC PSU fan.

Check the temp of the air coming out of the PSU, it's not even close to the
rating of panaflo fan. Panasonic even recommends their fans for PSUs, IBM
used them in their $5000 PCs Power supplies.

I have removed enough frozen and sticky 80mm sleeve bearing fans to
cover the walls of my house. I rarely (or never) encounter a failed
ball bearing fan.

Because the manufactures used cheap fans.

I notice you didn't mention *why* one should never put a ball bearing fan
into a PC. Well? Why not?

Noise, they get louder as they get older.

Lane

 

[kony]

A quality sleeve bearing fan will last a dozen years. even in a PSU, even
horizonally mounted. Where did you get that "NEVER" from :O)

Not necessarily, even Papst and Panaflo make ball-bearing fans, and
they spec the ball-bearing fans for high-heat applications, a far
lower MTBF for sleeve bearings as temp rises. There aren't any
high-end power supplies of typical PC wattage, that use sleeve-bearing
fans... ever wonder why?

Also consider, that you're not really arguing FOR sleeve-bearings, but
only two specific lines of fans... the "average" cost and quality
sleeve-bearing fan is quite inferior to the "average" ball-bearing
fan. If we're going to consider specifics, then we need also consider
chassis airflow, design, how this impacts fan selection, to the end
that when low-RPM fans are used, either bearing type can yield a fan
that's not the loudest part of a system.

Sleeve-bearings are not suited for any mounting position other than
vertical, it is inherant in the "sleeve" design, is not something that
even Panasonic's hydrowave can effectively counter. Sleeve-bearing
MTBF ratings are only applicable to vertical mounting unless
explicitly stated otherwise.

Cheap fans fail not high quality ones.

Where might one buy a high-quality sleeve-bearing fan for video card
or northbridge?

Ball bearing fans are reasonably quiet when you first install them and then
unlike a sleeve bearing fan get progressively louder as they wear, negating
the small difference in mtbf since they have to be replaced due to noise
anyway.

The difference in MTBF is a much larger difference that you'd imply if
the fan is used for anything more than a case intake or exhaust.
Ball-bearings typically get a bit louder, but not a linear noise
increase, and it also depends on the particular fan. We can't very
well compare only the two best sleeve-bearing fans to "any old"
ball-bearing fan. In a low-RPM fan the noise difference is very
slight, but at higher RPM the turbulent noise of either fan is louder
than a ball-bearing, again assuming we're talking about quality fans.

Sleeve bearing fans got a bad rap due to the large number of failures of
low quality fans. I recently pulled a panaflo from a PSU that was in a IBM
486 Valuepoint that cost $5000 at the time (94). It was still working
perfectly.

Sure, in a very low-heat environment. Today the power supply alone
can create more heat than that entire system did. I do not dispute
that a Panaflo or Pabst fan is a very good, perhaps best choice in a
low-heat, vertical mounting. Check out specs from any major fan
manufacturer, they all agree that ball-bearing fans are to be used in
an elevated-temp environment.

Lets look at it another way... back then, on that system they used
sleeve-bearings, but what about today, after years more experience and
with modern systems? All the major OEMs use ball-bearing fans AFAIK

The only advantage of BB fans is noise. Usually before they quit all
together they will make one heck of a racket warning the user to replace it.

That benefit is the time-frame, in that a noisey ball-bearing fan may
work for a long, long time before it actually fails. The similar
failing sleeve-bearing fan may not spin up at all the next time a
system is started, damaging component(s).

If I had to pick the *best* fan for a case inlet or exhaust I'd pick a
Panaflo, but by a very small margin over many different manufacturer's
ball-bearing fans, but also depending on the cost.


Dave

 

[ric]

Noise, they get louder as they get older.

Wrong again. Cheap sleeve bearing fans are relatively quiet when new,
but grow noisier as they age and their lubricant dries out. Ball bearing
fans do not suffer from this malady. You have it back-assward.

 

[Halfgaar]

Let's consider another application. Harddisks. Before oilbearing was common,
they used ball bearing, right? Harddisk get quite hot, so appearently ball
bearings are able to withstand the heat. And, harddisk bearings should be
quite reliable.

Halfgaar

 

[Lane Lewis]

Wrong again. Cheap sleeve bearing fans are relatively quiet when new,
but grow noisier as they age and their lubricant dries out. Ball bearing
fans do not suffer from this malady. You have it back-assward.

Note that I'm only referring to high quality fans, I think I made this
quite clear. Between a high quality BB fan and a sleeve bearing fan the BB
fan will make more noise and get progressively louder as it ages, the sleeve
bearing will not and it will not dry out for the life of the PC.

Lane

 

[Lane Lewis]

Let's consider another application. Harddisks. Before oilbearing was common,
they used ball bearing, right? Harddisk get quite hot, so appearently ball
bearings are able to withstand the heat. And, harddisk bearings should be
quite reliable.

The heat from a hard drive is several times that of a PC there just is no
relevance at all.

Lane

 

[ric]

Note that I'm only referring to high quality fans, I think I made this
quite clear. Between a high quality BB fan and a sleeve bearing fan the BB
fan will make more noise and get progressively louder as it ages, the sleeve
bearing will not and it will not dry out for the life of the PC.

Quality ball bearing fans do not get noisier as they age, no matter how
many times you claim that they do.

 

[Lane Lewis]

Not necessarily, even Papst and Panaflo make ball-bearing fans, and
they spec the ball-bearing fans for high-heat applications, a far
lower MTBF for sleeve bearings as temp rises. There aren't any
high-end power supplies of typical PC wattage, that use sleeve-bearing
fans... ever wonder why?

Marketing.

Check the temp of the air flow from your PSU, it's not even close to the
temp that would bother a well made sleeve bearing fan.

Note that they give identical ratings for BB and Sleeve except for decibles.
MTBF is 9 years at 40C, check your exhaust temps.

http://www.papstplc.com/downloads/DC/8300.pdf

Also consider, that you're not really arguing FOR sleeve-bearings, but
only two specific lines of fans... the "average" cost and quality
sleeve-bearing fan is quite inferior to the "average" ball-bearing
fan. If we're going to consider specifics, then we need also consider
chassis airflow, design, how this impacts fan selection, to the end
that when low-RPM fans are used, either bearing type can yield a fan
that's not the loudest part of a system.

Not the point, why add noise to a system when there is no reason to. High
quality panaflow fans are as little as $5 and will last the life of any PC
even at several degrees higher than the average temp of a PC.

Sleeve-bearings are not suited for any mounting position other than
vertical, it is inherant in the "sleeve" design, is not something that
even Panasonic's hydrowave can effectively counter. Sleeve-bearing
MTBF ratings are only applicable to vertical mounting unless
explicitly stated otherwise.

Sleeve bearing fans can be mounted in any position and run just fine with no
loss of mtbf. Note that you are correct when you get into larger motors <
1HP but almost all AC units nowadays mount their sleeve bearing fan motors
horizonally on the outside unit.

Where might one buy a high-quality sleeve-bearing fan for video card
or northbridge?

I use 80mm fans to protect my video card and motherboard, though with many
high end vid cards this might not be possible. But even the ball bearing
fans on most vid cards put out way to much noise.

The difference in MTBF is a much larger difference that you'd imply if
the fan is used for anything more than a case intake or exhaust.
Ball-bearings typically get a bit louder, but not a linear noise
increase, and it also depends on the particular fan. We can't very
well compare only the two best sleeve-bearing fans to "any old"
ball-bearing fan. In a low-RPM fan the noise difference is very
slight, but at higher RPM the turbulent noise of either fan is louder
than a ball-bearing, again assuming we're talking about quality fans.

If the fan is making noise because of turbulence then you have a poorly
designed system, a bigger heatsink might help or a better case with more or
better positioned fans.

Sure, in a very low-heat environment. Today the power supply alone
can create more heat than that entire system did. I do not dispute
that a Panaflo or Pabst fan is a very good, perhaps best choice in a
low-heat, vertical mounting. Check out specs from any major fan
manufacturer, they all agree that ball-bearing fans are to be used in
an elevated-temp environment.

A PC is no where near a high heat enviroment for a sleeve bearing fan. Check
the temp of the exhaust of the PC or the PSU. In most cases its just a
degree or two above ambient. If its not then the system is poorly designed.

Lets look at it another way... back then, on that system they used
sleeve-bearings, but what about today, after years more experience and
with modern systems? All the major OEMs use ball-bearing fans AFAIK

All Marketing and cost cutting.

it.

That benefit is the time-frame, in that a noisey ball-bearing fan may
work for a long, long time before it actually fails. The similar
failing sleeve-bearing fan may not spin up at all the next time a
system is started, damaging component(s).

Yes but who can put up with the noise.

Lane

 

[kony]

Marketing.

Check the temp of the air flow from your PSU, it's not even close to the
temp that would bother a well made sleeve bearing fan.

Note that they give identical ratings for BB and Sleeve except for decibles.
MTBF is 9 years at 40C, check your exhaust temps.

http://www.papstplc.com/downloads/DC/8300.pdf

It's not hard to have 40C exhaust. High-end P4 with similar high-end
video card, a few drives, etc, will create over 160W of heat at full
load. If the user has a giant case they can fit all the fans they
want and easily achieve ~22CFM needed to keep temp rise at 10C, but
they'll need minimum of two fans to do it since fan's free-air rating
doesn't correspond to realized airflow, and beyond a certain point the
additional openings in the chassis are counter-productive, will allow
more noise to escape. That 10C rise isn't always in a perfect
air-conditioned environment, some systems are in sunlight or near a
heater/vent or clustered together.. for a variety of reasons there
needs be a margin enough to tolerate moderately elevated temps.

Not the point, why add noise to a system when there is no reason to. High
quality panaflow fans are as little as $5 and will last the life of any PC
even at several degrees higher than the average temp of a PC.

But you are only adding sound energy, the "noise" is what we hear. If
the difference isn't audible outside of the chassis...

Sleeve bearing fans can be mounted in any position and run just fine with no
loss of mtbf. Note that you are correct when you get into larger motors <
1HP but almost all AC units nowadays mount their sleeve bearing fan motors
horizonally on the outside unit.

Nope, every time mention is made of mounting position and how it
affects lifespan, the mention is that it does reduce MTBF. If you
know of a manufacturer that claims otherwise please disclose this.

I use 80mm fans to protect my video card and motherboard, though with many
high end vid cards this might not be possible. But even the ball bearing
fans on most vid cards put out way to much noise.

Almost no video cards come with ball-bearing fans, is a large part of
the reason they have such poor failure rates. Any video card I've
owned in the past few years of any significant value had it's fan
replaced with a good ball-bearing fan, BEFORE those junk
sleeve-bearing fans had enough wear to ever approach failure or
elevated noise from wear.... all of those fans still work today and
have lower noise than original, lower noise than would be audible in
most PCs considered quiet.

If those vid cards had started out with a Panaflo or Papst fan, I
"might've" considered leaving the fan on, but would still be more
concerned than with the more appropriate ball-bearing counterpart.

If the fan is making noise because of turbulence then you have a poorly
designed system, a bigger heatsink might help or a better case with more or
better positioned fans.

A nice idea but most people don't want to replace their cases or do
any more modifications than necessary. A side-by-side comparion of
two Panaflo H1A fans outside of a case, one ball bearign version and
the other the sleeve bearing version, shows negligable noise
difference. The free-air turbulence is by far louder than the
bearing. It's also true of the M1A. I don't know if L1A was made in
a ball-bearing version though so I can't compare them, but I can
compare to slighly higher RPM NMB fans, which are slightly louder, the
difference is only noticable in a very quiet system. The NMB fans
have similar MTBF rating at low temp (and when the L1A is vertically
mounted) yet the NMB typically costs a lot less. It brings up an
important point, in that these Papst and Panaflo fans are often
low-RPM, but users compare them to far higher RPM ball-bearing fans
then draw the wrong conclusion.

A PC is no where near a high heat enviroment for a sleeve bearing fan. Check
the temp of the exhaust of the PC or the PSU. In most cases its just a
degree or two above ambient. If its not then the system is poorly designed.

Almost every PC made in the past few years has a higher than 2C temp
difference. It would take more airflow than two quiet (low RPM) 80mm
sleeve-bearing fans realize to keep the temp difference under 5C in a
well-designed system producing 100W heat. I think Papst's master fan
catalog has some details to compare to their models, but unfortunately
they can't begin to predict how much the free-air rating will decline
in a chassis. The last info I recall suggested that airflow is more
than cut in half in a common, properly arranged system.

All Marketing and cost cutting.

How could it be marketing when the OEMs don't advertise which fans
they use, when the buyer may not know even after they have the system?
Quite a few OEM systems are quiet, yet they use ball-bearing fans.
I should probably repeat that as it's worth repeating:
Quite a few OEM systems are quiet, yet they use ball-bearing fans.

It's not cost-cutting to use ball-bearing fans when you're an OEM,
they buy enough fans to get a more accurate volume price making their
decision to use ball-bearing fans a minor extra expense. They are the
preferred, high-volume customers, who can spec ANYTHING they want, and
they choose ball-bearing fans more often than not.

Perhaps the Pabst would be more expensive, but I know the Panaflos are
cheaper in the sleeve-bearing version.

Yes but who can put up with the noise.

The quality ball-bearing fan runs fine for a decade or two, then near
the end of it's lifespan there is the noise increase I refer to above
as "noisey", NOT during the servicable years, so the user then has a
few weeks or months to act, instead of (possibly) a single power-cycle
of the machine as with a sleeve-bearing fan. Granted that's more
common with cheaper sleeve-bearing fans, but again you didn't disclose
where someone might buy a good sleeve-bearing fan for video card or
northbridge... not everyone can fit 80mm fans in odd places.



Dave

 

[Lane Lewis]

Quality ball bearing fans do not get noisier as they age, no matter how
many times you claim that they do.

http://www.comairrotron.com/Engineering/CoolingFan.htm

Note that it does mention heat at the end of the article but PCs do not
generate the high heat that would affect a sleeve bearing fan which is rated
at up to 70C and still have a life expectancy of 4 years cont. PCs run
nowhere near that temp and are generally below 40C with a fan life
expectancy of 9yrs.

http://www.papstplc.com/downloads/DC/8400n.pdf

Lane