Re: How to choose the optimal 120mm fan?
 

My first wc build, and need help deciding on fans for u2 ufo case, with pa120.3 rad. Would like to keep it quite under 30db ( 9 fans,is it possible? ). Plan to get a performance board and a dual opty or amd x2). Will I be able to push this cpu using fans in the 47- 55 cfm range? (4412fgl or yl d12sl-12) or lower in the 37 cfm range (nexus 120), using pa120.3 rad?
also looking at t-balancer to undervolt any of the above fans during idle.

thanks

Re: How to choose the optimal 120mm fan?
 

I had the 3.5" version and it was noisy so I sent it back and shallowed 15% restock fee. Those old fan controllers are ancient and there are many new fan controllers that are better. Decent controller should go lower than 7V.
Zalman has one that switchs from 12 V or 5 V and PWM, makes life really easy.

I really like the T-balancer or crystal fontz reviewed by Joe. Haven't got my grimmy hands on one yet but I will soon. $$$ shortage.

Cathar's response to another post
http://forums.procooling.com/vbb/sho...134#post152134

SALKIN

9 blade fan = glacialtech silentblades.
I heard at low RPM these 25mm fans ~ nexus fan but degrade with age because of ball bearings. I never heard about 35mm fan but I bet it's similiar to panaflo or worse.

Re: How to choose the optimal 120mm fan?
 

I have one too. Silent. Totally silent. Unsure what was wrong with yours.

Heck, I even ran a Laing D5 pump off one of the channels at 12v for a while (~30 mins) before I realised what I was doing and how much load I was putting on the controller. It handled the load just fine, but the channel controller that the pump was on sure got hot. Extremely hot, but it coped.

Re: How to choose the optimal 120mm fan?
 

Salkin
Heatercores are not silent focused or even designed for WCing. Thermochill rads are and the PA series is focused towards silent WCing. Apples and Pears.

Look at the link and the PA fans have a very low fin density to the point I was shocked. Swiftech rads are not a bad choice and I would buy them myself but I would get a Thermochill rad if I had the money.

Re: How to choose the optimal 120mm fan?
 

Maybe an older vantec versions? Mine had a slighy buzz like a UV light module kit.

Re: How to choose the optimal 120mm fan?
 

BTW the Adda 1212LB is used by Lian Li for their high end V-Series cases, and by Seasonic for their high end 500W/600W PSUs. I got mine with the Lian Li :P
Here are the specs
adda 1212LB:
1800 rpm
72 cfm
pressure 0.095"
34.4 dBA
Nice noise/performance ratio in my opinion.
The Delta i cited is comparable to the Panaflo Bill is using for his tests (and yes i was surprised to find a 'quiet' fan with a Delta label !)
The best thing to do is what Bill said: buy several fans, compare them, keep the best according to your tastes, sell the excess

About fan controllers it's to be noted that Papst fans dont like PWM at all, they produce a hum. An adequate controller would be the m-cubed MiniNG (which is also adequate for Laing pumps btw), it's smaller than their flagship T-balancer controller and less expensive. It has only 2 headers though (still adequate for 1-fan systems :P) and you can choose between PWM and analog. It has a proper heatsink so it won't fry in analog mode :)

Re: How to choose the optimal 120mm fan?
 

Is there a general rule of how much static pressure mmH2O is enough for radiatorcooling or do I miss other factors?
There's a Coolermaster fan - 120x38mm, 1200RPM (wee), 56CFM and a static pressure of 1,40 mmH2O - is this good for a radiator like PA120.1 or Swiftech MCR120.
- Coolermaster fan link

Is the static pressure proportional so if it's "1" at 2000RPM it's "0,5" at 1000RPM?

Am I wrong if I assume that the more static pressure per RPM a fan makes the better is it for radiatorcooling?

I know, but the heatercores like Chevy86 where a good choice because they had low water and air resistance, but they are to thick for low CFM fans.

Re: How to choose the optimal 120mm fan?
 

The more pressure the better. The problem is that, in general more pressure means more noise. So, the question is how much noise will you tolerate?

Manufacturers don't publish RPM vs Pressure curves. Nore do they publish RPM vs Noise curves. Fans are designed to do a specific job. Most (non watercooling ppl) just buy the fan that fits and delivers the required CFM. Undervolting is not used in the "real world". This freekish community has discovered undervolting and thereby opened up a whole new world of fan choices. I see undervolting as a really, really nit pickey way of getting the CFM vs noise ratio to that ever elusive "sweet spot". IMHO, picking a fan that gives the max cooling at the rated voltage is the way to go. Then undervolt to get less noise for those times when you don't need max cooling. How much undervolting? how much noise? those are personal preferences. With the availability of PWM comtrollers it's hard to go wrong with any fan that gives you the cooling you need. I'm putting together a 2X120 Rad with 2 190 CFM fans, will it be loud...h@#% yes! can I get the fans to run slow enough to be livable and still provide adequate cooling for non intensive use? probably.

Is more static ressure per RPM better is a question like " Is blue bigger than 47 degrees celcius?" It doesn't matter. It's noise and cooling.

And I agree "thick" or anything else that impeeds airflow requires higher flow (higher noise and higher RPM) fans.

Re: How to choose the optimal 120mm fan?
 

Re: How to choose the optimal 120mm fan?
 

yes this is not a linear relation

Here is an example of flow vs pressure curve - for instance the graph for the papst 4212 NGML (38 dBA @12V)
http://www.papst.de/images/public/co..._x251_y251.jpg
and the 4212 L (28dBA @12V)
http://www.papst.de/images/public/co..._x251_y251.jpg

And more interesting they have "variofans" so they publish speed vs pressure/flow curves:
http://www.papst.de/images/public/co..._x251_y251.jpg
this is for a 80x25 variofan, controlled by a thermistor, so it's temperature which varies, but basically the thermistor (with its control circuitry) varies the voltage between 8V and 12V. The only problem is the thermistor response to temperature linear ? Like billbartuska said we are a special population - when engineering products for the industry the provided graphs are enough, you just want to know temperature vs flow, the actual voltage / rpm is not relevant.

Re: How to choose the optimal 120mm fan?
 

I really like the Sunbeam Rheobus. It's a 4-channel controller with linear regulation up to 20W per channel. Construction quality seems a lot better than the Nexus and Zalman units I've seen. They're only $9 right now at Jab-tech .

Re: How to choose the optimal 120mm fan?
 

I think is goes 0-12 Volts as well. In general, there are many fan controllers to choose from that are better quality and more functional than old school nexus controllers.

Salkin
The panaflos M are very quiet at 7V. They vibrate a little bit but if you isolate them properly you can hardly hear them at 7V. The Panaflo M series at 9 V is about the same as L series.

Re: How to choose the optimal 120mm fan?
 

I wrote to Silverstone and requested performance curves for their 120mm fans (FM121 and FM122).

Now I have them I thought if you could read them? no values are written - there's just a curve.
Should I write them for futher information or does the curves tell if they are good fans for watercooling. The FM122 should be designed for high air pressure operation.

Re: How to choose the optimal 120mm fan?
 

noise vs. speed
need the other curves to consider

but only by comparative testing will you know
specs alone are not sufficient

Re: How to choose the optimal 120mm fan?
 

True.

1) Specs lie. Some more than others.
2) Ears are different.

Re: How to choose the optimal 120mm fan?
 

Okay, I think I have the correct graphs now. How does it look for the fans in theory?

The left graph is FM121 and the right FM122

Re: How to choose the optimal 120mm fan?
 

The Sany Denki San Ace 120mms I have modded to 7V are pretty damn quiet in comparison to my old Panaflos. I also tested them at 5V and they are virtually silent.

I only decided to use 7V for now since it seems to help keep things a bit cooler.

The Nexus controller I was using before seemed to make these particular fans buzz to all hell. No idea why.

Re: How to choose the optimal 120mm fan?
 

How much for the fans and can you provide a link from where you pruchased it if possible.

EDIT:
I went to Sanyo Denki website and saw some large fans. Is there any reasons why no one suggest larger fans like the 140 x 38mm fan or 140x50mm fans?

Re: How to choose the optimal 120mm fan?
 

I bought my fans from this guy: http://www.hardforum.com/showthread.php?t=974021

Re: How to choose the optimal 120mm fan?
 

Just my two cents.

I have some Sanyo Denkis that are wired for 7 volts and are fine. Never had a problem with them not starting. They dont have a motor whine but they do have a bearing noise and when combined with the radiator they make more noise. Right now my fan on my evga 7800gt is louder than the Denkis at 7 volts(at 12v they are unbearable).

I was thinking of getting M1as but at 7v they put out slightly less air than the Yates-Loon at 12v and the noise is about the same.

I have 3 Yates loon also and will test if there is any temp difference in my system between Yates at 12v and Denki at 7v with a PA 120.3.

Re: How to choose the optimal 120mm fan?
 

I was about to Post Panaflo... from personal experience they're silent and perform admirably.

Re: How to choose the optimal 120mm fan?
 

These coolermasters are very nice. I think Cathar may even think they are quiet :evilaugh:

http://www.anonforums.com/builds/bea...03/fullrad.jpg

Re: How to choose the optimal 120mm fan?
 

there seems to be a very large gap between the fans ?
if so is wasted fannage (put a cig there and watch the smoke)
whose rad ?

Re: How to choose the optimal 120mm fan?
 

Looks like a Thermochill 120.3, and it looks like he's not using the supplied spacer material that blocks off those gaps.

Re: How to choose the optimal 120mm fan?
 

It is a PA 120.3. There was no supplied spacer. Marci?

Re: How to choose the optimal 120mm fan?
 

Those fans are about $25 each at ZipZoomFly. So there is about $250 worth of rad and fans in that picture.

Seems rather expensive to me. Or am I way off?

Edit: Each fan draws 1 amp as well. So there goes 70 watts off the +12v line.

Re: How to choose the optimal 120mm fan?
 

Umm yeah but www.clubit.com was running a special on these fans a while back, $10.99 each and a $10.99 rebate (one fan only). So I bought 5 fans and got one free. Cost me less than $60 for six shipped.

Re: How to choose the optimal 120mm fan?
 

Very nice! :cool:

Was wondering....:rolleyes:

Thanks for the link I will have to check it out.

Re: How to choose the optimal 120mm fan?
 

He's referring to the neoprene gasket that should have come with the rad... s'on Thermochill.com as NG120.3 (http://www.thermochill.com/acatalog/...cessories.html)

Should have been one included with the rad...

Re: How to choose the optimal 120mm fan?
 

Marci I ordered the rad directly from Thermochill as soon as they were available... no gasket came with mine.