Question 1

Hi, should I get this or the Noctua NF-F12 for a case fan?   Thanks.

Accepted Answer

If your fan location doesn't have any filters or obstructions then the S12a will be what you want, but if it does have any sort of filter, or resistance the fan has to pull through, you'll want an NF-P12.  Several reviews have remarked that in a resistance based location the P12 works just as well as the F12, and does so with less noise.  The F12 would only be better for high temp heatsinks with its higher RPM range.I personally own all 3 types and have an F12 on my CPU heatsink, 2 P12 fans as intakes that are behind a dust filter, and 1 S12a as a rear exhaust.  I previously used 2 S12as as the intakes but they were really loud behind the filters.

Question 2

What is the difference between the PWM,  the ULN and the FLX versions?

Accepted Answer

PWM is the most standard version. People who want to push a little extra air but still stay quiet and keep up with a mild overclock, these are also 4 pin.ULN is targeting users who hate sound. These are lower voltage and push less air.FLX is the dynamic fan, you can run it a little higher or lower watt and push a littler higher or lower air.Personally I can't see any reason to use anything but PWM. They even come with a free adapter to lower the voltage if for some insane reason this already super quiet fan isn't quiet enough.

Question 3

What is the cfm at min and max rpms?

Accepted Answer

For a given RPM there is a performance curve; Maximum CFM at minimum static pressure, minimum CFM at maximum static pressure and all the points in between.

Question 4

Are these sealed bearing fans?

Accepted Answer

From the Noctua FAQ:In order to ensure flawless operation over many years of usage, all Noctua fans come with a premium grade SSO bearing, which is fully sealed to prevent the entering of fine dust particles. Please note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty.

ASIN	B00BEZZBFO
Air Flow Capacity	107.5 cubic meter per hour
Best Sellers Rank	#517 in Computer Case Fans
Brand Name	Noctua
Compatible Devices	Desktop
Cooling Method	Air
Customer Reviews	4.9 4.9 out of 5 stars (3,154)
Global Trade Identification Number	04716123314929
Item Dimensions L x W x H	4.72"L x 4.72"W x 0.98"H
Item Weight	6.4 ounces
Manufacturer	Noctua
Material Type	Fibre-glass reinforced PBT
Maximum Rotational Speed	1200 rpm
Model	NF-S12A PWM
Noise Level	17.8 db
Number of Items	1
Number of Packs	1
Part Number	NF-S12A PWM
Power Connector Type	4-Pin
UPC	808111663660 863121543098 731215276828 846764214297 807320183181 842431014252 809394261574 803982961709
Unit Count	1 Count
Voltage	12 volts
Warranty Description	6 year manufacturer’s warranty

NF-S12A PWM, High-Performance Quiet Fan 120mm

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