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PostPosted: Mon Aug 12, 2002 2:32 pm 
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Hi, I am looking for a quiet case fan, and I happened upon the Panaflo FBL 80mm fans at <!-- BBCode Start --><A HREF="http://www.siliconacoustics.com" TARGET="_blank">SiliconAcoustics</A><!-- BBCode End -->. They say that the FBL series is just as quiet as the Panaflo FBA series, but can move up to 50% more air. Have any of you checked these out for yourselves? Would SilentPCReview be willing to test these fans to see if they really are as quiet as advertised? Thanks.
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PostPosted: Mon Aug 12, 2002 2:32 pm 
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So happens I just got one to test -- from Silicon Acoustics, in fact! <br> <br>It's too early for me to judge, as all I've done is plugged it in and listened / felt the airflow. My first impression: It does seem to blow more air and makes about the same level of noise. <br> <br>One caveat, which they mention: "it only has mounting holes on the label (outflow) side". SA also suggest not using it direclty against the HS because "high backpressure will defeat the effect". <br> <br>So perhaps the best way to use them mounted over the HS, Zalman fan style. <br> <br>
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PostPosted: Mon Aug 12, 2002 2:32 pm 
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Wow, thanks! Now when you say that the noise level is about the same as the FBA, what does that mean? In particular, how does the noise level of the FBA compare to the noise level of the Zalman PSU at 25C ambient temperature? <br> <br>Also, how do the FBL/FBA perform when put behind a fan grill? Does it create much turbulence (i.e. noise)? Thanks.
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PostPosted: Mon Aug 12, 2002 2:32 pm 
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The fan used in the Zalman is a 0.23A Globe Fan, basically the same one used in an Enermax. I believe the min. voltage is lower, however, as it starts out quieter than in the Enermax. <br> <br>The Panaflos are instrinsically quieter, as they are rated at only 0.1A and spin at 1900 rpm max (compared to 3000+ for the Globe Fan). But at such a low voltage feed, you might not hear the difference. <br> <br>If, on the other had, the Zalman fan spins faster as the PSU gets warmer, the Panaflos will definitely make an audible difference. <br> <br>Any / all fans make more noise behind a grill. That's not fan-specific; the airflow causes the turbulence and noise. At slow fan speeds, however, this turbulence becomes irrelevant as it is inaudible. <br>

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PostPosted: Mon Aug 12, 2002 2:32 pm 
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Hi, thanks for all of the info. By the way, do you know anywhere else that sells the Panaflo FBL fans? I can't seem to find anywhere other than SiliconAcoustics (and the $17 price tag is quite high).
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PostPosted: Mon Aug 12, 2002 2:32 pm 
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No, I haven't seen it anywhere else either, but Silicon A. has lots of other useful goodies -- you might want to get a bunch of stuff at once to make the shipping worthwhile.
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PostPosted: Sun Aug 25, 2002 10:43 am 
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I'm also curious about the FBL fan. I've tried to send e-mail to support@siliconacoustics.com and only get bounces. Their website claims the FBL is otherwise identical to their other 92mm Panaflo. However, in looking at the data sheets for Panaflo at www.digikey.com, I see no FBL model that corresponds to the FBA09A12L1BX.

MikeC, do you know the FBL model number?

I also note that NMB used to list a 92mm vented fan (3610KL -vented), but I haven't found a vendor selling them.

Thanks in advance.


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PostPosted: Sun Aug 25, 2002 4:29 pm 
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The photos at Silicon Acoustics sahows you the precise difference: the 4 sides have slits cut away in them. That's the difference.

What apparently happens is that in a normal fan, turbulence builds at the tips of the fan blades, which of course, have the highest velocity because they're farthest from the center. By providing access to "free" air at the edge location, these slots allow the high velocity of the blade tips to actually create more airflow & reduce turbulence noise.

It works something like that. :wink:

As I mentioned earlier, I believe much of this gain is lost if you're running the fan at low speed, the gain is only there if you're running the fans pretty close to 12V.


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PostPosted: Tue Aug 27, 2002 10:13 pm 
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You can also find the FBL series fans at Digikey.com. Just do a search for "FBL fans" They've got them in every size from 60mm to 120.

I also stumbled upon this pdf on panasonics site, it gives alittle more information.

Panasonic PDF


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PostPosted: Tue Aug 27, 2002 10:45 pm 
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Ok, now I'm confused. I did some more looking on digikey's site and pulled up their catalog page for panaflo fans:
http://info.digikey.com/T022/V5/0872.pdf

Now according to panasonic's pdf on the FBL series, "Newly-Developed Turbulenceless Structure brings higher volume of air lower noise and saving energy" (sic)

But when you compare the old FBA's to the new FBL's its kinda odd. Take for example 92mm FBA L1A, compared the 92mm FBL L1A:

FBA: Input power=1.32w Max Air=42.7 Max noise=27.0dba
FBL: Input power=1.80w Max Air=31.77 Max noise=33.0dba

And the comparison appears to hold true across the entire product line.

So the new "higher volume, lower noise, lower energy" fan actually produces less air, with more noise, at higher wattage?

The FBA specs jive with those I've seen from other sites, so I'm assuming all of the fan specs come from Panasonic directly.

Mike, any ideas on this?

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PostPosted: Tue Aug 27, 2002 11:17 pm 
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IMO, trust Panasonic's own data: http://www.panasonic.com/industrial/app ... s_home.htm They should have correct info on their own products.


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PostPosted: Tue Aug 27, 2002 11:29 pm 
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Exactly my point, the FBA data on panasonic's site matches that on digikey's, which leads me to assume that digikey got all their data direct from panasonic. But panasonic's site doesn't even mention the FBL series. You can't even search for any of the FBL model numbers.

But I bet that if you could find the data on panasonic's site, it would match digikey's.

Which still doesn't answer the question as to what this new "FBL" technology is supposed to be gaining.

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PostPosted: Tue Aug 27, 2002 11:43 pm 
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Good point. All I've really read about it in any detail is here:
http://home.att.net/~alemont/noise1.html The detailed graph unfortunately is not available...


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PostPosted: Wed Aug 28, 2002 12:25 am 
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Yeha, I saw that too. I really wish their site was working properly, I about gave myself a migrain trying to read that graph. There's another little graph on the digikey catalog page that supposedly compares the FBA and FBL in terms of noise and airflow, but I don't see its numbers being backed up by the data.

I own a 120mm and a several 80mm FBA L1A's, maybe I'll have to add a couple of the FBL's to my fan collection and do a head to head comparison. I'll be sure to report back with any results.

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PostPosted: Thu Aug 29, 2002 2:32 pm 
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As you must have read, the FBL series fan is basically the FBA series fan with the "augmented" design licensed from Lemont Aircraft Corporation (LAC), as mentioned in the link to the Lemont's own site you posted Mike.

Panasonic and NMB have lincenced this technology for awhile and have sold them through OEM lines. They have been available from Digikey for awhile.

One current use of augmented fans that is well known in the silent PC community is Millennium Thermal Solutions, http://millennium-thermal.com/, known for their low-noise Glaciator series of heatsinks/fans designs the heatsink around a augmented fan. They even have a repost of Lemont's white paper on their site.

The noise reduction is mostly from tip-vortex alteration from the ringcage.

If you look at the data from Digikey's catalog, http://info.digikey.com/C022/V5/SectL.pdf, pp 872, for the 92mm fan, at the low and high CFM, the FBA does slightly better. But! at the middle range of CFM, the FBL is significantly lower dB-A, the best case at ~24 CFM, the FBL is 4 dB-A below the FBA.

If you look at the P-Q curves, the FBA significantly better perfomance in at 0 pressure, as much as 7 CFM more. But under realistic presure, the FBL performs same to much better starting around 1 mmAq and higher. The FBA outperforms the FBL at maximum pressure, but the FBL outpaces the FBA until about 3.5 mmAq. That means, the FBL should do better than FBA in most heatsink applications, but both are lousy under heatsinks that will generate a lot of backpressure(> 3.5 mmAq).

Because of this, most of us use Panaflos for low-pressure applcations, e.g., case fans, which they are well suited for. The question is, for case fans, does FBA or FBL perform better? Well, that depends. If the pressure is less than 1 mmAq, then FBA perform significantly better. Above that, FBL perform much better. I don't know what a typical case fan on a mid-case PC would see. Does anyone know this number?

One last thing: FBL have a disadvantage in clearance over the FBA. Because of the ringcage design, the side of the ring cage needs to be somewhat clear for it to be effective. For this reason, as well as the lower maximum pressure, the FBL would probably do horrible as powersupply fans. Also, to get maximum advantage from the ring cage effect, the fan should be mounted half-in/half-out. Standard cases do not provide this mounting mechanism. As you can see, the augmented fan, FBL series, performance is highly dependent upon the placement in the system.


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PostPosted: Sat Aug 31, 2002 12:08 am 
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So if I use an Alpha PAL 8045 cooling an Athlon XP 2200+, which is better, FBA or FBL?


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PostPosted: Sat Aug 31, 2002 3:18 am 
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probably FBA, and not because of the P-Q curves. if you look at the ring cage design and airflow patterns, the flow of air is not as directional as a monolithic housing of the FBA. therefore, even if the FBL was mounted on top of your alpha hs sucking air, the FBL would partially suck air around the heatsink instead of from the the center of the heatsink.


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PostPosted: Mon Sep 02, 2002 9:06 am 
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Thanks for the info Hyum. That clears up alot of my questions about these fans. That one of the great things about this forum, there's always someone who has the answers. :lol:

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PostPosted: Mon Sep 02, 2002 9:23 am 
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hyum wrote:
One current use of augmented fans that is well known in the silent PC community is Millennium Thermal Solutions, http://millennium-thermal.com/, known for their low-noise Glaciator series of heatsinks/fans designs the heatsink around a augmented fan. They even have a repost of Lemont's white paper on their site.


Lemont is actually the name of the family that own a helicopter (propellar design/mfg?) business, started by the father of the man who started Millennium Thermal Solutions. In other words, Lemont & MTS are basically one and the same, or at least part of one family. Just FYI. :wink:


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