Panaflo FBA vs FBL series fans?

IceFire · Post by **IceFire** » Thu May 01, 2003 9:17 am

I am looking at the Fanaflo FBL series fans. FBL are "Louvered design increases air flow and decreases turbulent noise at standard rating conditions." While the FBA are "fans force air out in a 'funnel' type pattern and are ideal when cooling a specific area that is surrounded by numerous components with minimum ventilation available." FYI, the ones normal discussed on the forum are the FBA.

Specs: for 80x80x25.5 mm, 12 volts
input power: FBA-0.84w, FBL-1.2
Max. Air Flow: FBA-24, FBL-17.3
Max Noise (dB-A): FBA-21, FBL-26

So according the spec, the FBLs are louder while reducing airflow. But according to the discription of the FBL, it should be quieter and moves more air. Could someone enlighten me on this? Does anyone have FBL fans?

herosformula · Post by **herosformula** » Thu May 01, 2003 9:50 am

I assume you are looking at the Digikey page?

Look to the lower left and you will see a chart showing the noise/CFM curves for the two series of fans. Notice that the curve for the FBL series stays lower for a wider range of CFM values whereas the FBA series remains at low noise for only one flow rate.

If you choose your CFM vaues carefully, you can take advantage of this. For instance, at 24.7 CFM (where there is the greatest difference) a FBA will be 46 dBA, whereas a FBL is at 42 dBA.

This chart is valid for only one fan, and there is no way to determine which fan Digikey is referring to, but I am assuming that all fans in a series operate in a similar manner.

IceFire · Post by **IceFire** » Thu May 01, 2003 10:31 am

Yes I am looking at the digi-key page.

Using your example. A 80mm 24 cfm FBA fan is spec at 21 dB-A which is the L1 but a 80mm 24 cfm FBL is at 33 dB-A which is the M1. So is the chart wrong and the discription and the graph is right?

herosformula · Post by **herosformula** » Thu May 01, 2003 11:06 am

Neither is wrong, neither is right.

As I noted in the last paragraph of my previous response, we have no idea which pair of fans the graph represents. Therefore the graph gives us a relative idea of how two different styles of fans respond with respect to each other, but does not contain an answer for any specific fan that you may choose.

We can deduce from the graph that when the FBA series is that at a certain CFM, the noise is much lower than the the Max noise level given by the chart. The trick with the FBA is dialing in your CFM rate so that you are at that value.

The FBL, on the other hand, has a broader range of CFM values in which it has a much lower noise than the Max noise given by the chart.

IceFire · Post by **IceFire** » Thu May 01, 2003 11:31 am

God! I should have realize that that is max noise level and may not be the noise level at 12 v. It looks like from the chart that lower CFM is not always lower dB-A. Also according to the chart, it might be better to get a M1 or H1 or even U1 and adjust the voltage to get min. noise.

I wish they would also have a column for min. dB-A or a column with the range like 12 dB-a @7v and 21 dB-a @13.5v.

herosformula · Post by **herosformula** » Thu May 01, 2003 12:54 pm

Yes, the graph does show that the standard setup here, a FBA L1A runing at 5V, may not be the quietest solution.

Unfortunately, I downloaded some spec sheets from Digikey, and the Noise vs CFM graph is not repeated for specific fans. Perhaps Panasonic has a better spec sheet, but I have not found one yet.

Looks like trial and error may be the only option.

Panaflo FBA vs FBL series fans?

Panaflo FBA vs FBL series fans?

I should have know better