sorry for top posting but your text is long, but very useful.
I'll need a 120mm fan, space is plenty for 2 fans and my definition of quiet
is like having all your pc fans off, boot into bios and all you can barely
hear are the HD and the PSU. If temps are below 50-55C without fans, I'll be
glad, but if not, i would have a 120mm fan turn very slowly just to keep it
below that. But when I need to, I want a fan that will push enough cfm to
pass accross my rad which is a good 1.5in think. I was planing on using a
simple 3 postition switch with resistors to control the 1-2 fans. I could
have Off - Mid speed (7V) - high speed(12V).
I also used an aluminium reservoir, (
http://www.noiseisolator.com/wt-tb.htm ) to help in cooling. I'll pass the
water from pump-cpu-chipset-vga-reservoir-rad-pump. That way, the biggest
heat will be absorb by the reservoir and hopefully, I'll manage to run my pc
at stock speeds with no fans.
I guess im better off to start off with no fans at all, see how it goes and
try to use a temporary fan just to see how cool i can get it and see if a
really need these high cfm. I might be satisfied with a panaflo M but like
you said, some say its still loud even at low rpm. Ill see if can have a
shop around hear have me listen to the noise it make just to see. When
gaming, noise would not really be a problem, but when idle or like watching
a movie, I need dead silence.
(sigh) Not easy to have both silence and performance.

anyhow thanks for the great info kony.



"kony" <spam@spam.com> wrote in message
news:lrf6d1567hag4tf595uokdiiq8d3kvlj36@4ax.com...
> On Mon, 11 Jul 2005 20:33:06 -0400, "Frank"
> <Frank@hotmail.com> wrote:
>
>>Just want to know if anyone has one of these 100+ cfm sunon or panaflo
>>fans.
>
> I have both, have had/used/sold/etc several models and
> speeds.
>
>>I'd like to know how loud exactly they can be a full speed and how
>>quite and performing they can be at minimum revs.
>
> Which model, size, flow rate?
> Ideally you'd use the largest diameter and thickest fan the
> space allows. "Full speed" is relative to the particular
> model. If your concern is noise (as it should be, there is
> no need for max possible speed out of a large fan except in
> some kind of non-traditional system or extreme environment),
> then don't choose the fastest speed model in any give
> family. For example with the Panaflos, there's "L", "M",
> "H" and even higher in some models. Seldom is anything
> faster than "M" needed in a larger fan, and usually "L" is
> sufficient.
>
>>My application is to cool a watercooling HW Labs xtreme radiator.
>
> You seem to have left out a vital detail- What size fan it
> can accept.
>
> This can be signficant for the question posed in particular
> because Sunon's 120 x 38 mm fans don't respond well at all
> to voltage reduction. Far sooner than many, they begin to
> have too little torque to overcome the magnet and make a
> pulsing sound and far less linear RPM (& flow) reduction
> with no addditional noise reduction, even introduction of a
> new noise from the irregular RPM rate.
>
>>I went
>>watercooling to have a dead silent pc and not to overclock in general. So
>>the fan would always be at minimum revs and maybe turn it off if temps are
>>not too high. But when gaming, i'd like to have full power and noise would
>>be less of a factor but still, I don't want a vaccum cleaner in my pc.
>>I've
>>heard these fans a screaming loud.
>>Just want real life opinions about these. Other fan suggestions are
>>welcomed
>>too.
>
> The key to quiet is to keep fans at minimal speeds. If one
> fan at minimal speed isn't sufficient while gaming, add
> another fan, turning the 2nd fan on when heat rises.
> However, with an optimal fan strategy it isn't even
> necessary to control fans turning on/off or changing RPM at
> all. Remember that it is not at all necessary for a PC to
> always remain at a constant temperature, only to stay under
> your target temp. That's not advice against implementing a
> fan control of some sort, only that it isn't necessary and
> depending on the control method, could be less reliable in
> the longer term.
>
> Panaflo is your best bet. Papst are good too but pricy.
> This assumes vertical orientation of the fan, for
> non-vertical (horizontal or ANY other non-vertical angle)
> you may want dual ball-bearing rather than sleeve fans to
> prolong their lifespan in these orientations.
>
> Everyone has their own idea of what "quiet enough" is. It
> can vary based on chassis quality, mounting method for
> fan(s), and system placement in addition to other factors.
> Point being, some might find a 120x38mm "M" Panaflo quiet
> enough when undervolted. Most would find it louder than
> they "like" at full speed. Remember that you don't
> necessarily have to choose between the low-speed for idle
> and full speed, but could just as well choose between one
> undervolted speed and a higher undervolted speed during
> (gaming or whatever).
>
> This potential for never running at full speed unless you
> really need to, makes an "M" speed more flexible than "L".
> L speed is more tailored towards low noise though, and is
> sufficient for most systems especially if the case intake is
> large enough and mostly unobsstructed. Optimally more than
> one "L" speed would be used for the most control at lowest
> noise but if your case doesn't allow it, that may be the
> justification for the single "M" speed fan with more
> aggressive RPM throttling.
>
> Note also that to get fans to spin-up yet still be at lowest
> voltage, it helps to use a control method that limits
> voltage rather than current. For example, a simple 15 cent
> inline resistor does quite well for typical undervoltage
> needs, but to get a fan working reliably at lowest voltage,
> use series-diodes or perhaps one of the common integrated
> regulator chips such as a LM317. Using something like an
> LM317, you can also put a thermal sensor into the circuit or
> control it with a POT.
>
> While there are other fancier PWM based front-panel fan
> controllers, many produce a whining sound from their
> inductors, and those I've tried do not allow fan spin-up at
> as low a voltage, therefore higher final rotational speed.
>
> Some radiators place the fan a bit too close, producing
> additional turbulent noise. I'm not familiar with the one
> you mentioned but if that becomes an issue you might
> consider finding or making a shim to place the fan an
> additional cm away from the radiator. This will reduce the
> flow rate through the radiator, but even so, the slightly
> higher RPM needed to produce same flow rate can result in
> lower noise than having the fan too close- which again I"m
> not certain about on that particular radiator.
>
>