[SOLVED] Can a Noctua NF-F12 PWM, 4-Pin Premium Quiet Fan (120mm) be used as a case fan?

[Send_Help]

TLDR: Sorry for the mess below. Basically, Noctua NF-F12 PWM, 4-Pin Premium Quiet Fan (120mm) does not fit as a case fan. Is it a problem with my case? It was a lot of money for nothing. Thank you...



Hello everyone. So, in the process of building a new pc I've made a number of purchasing mistakes. I dont know if this is one of them.

I originally bought a set of Antec fans for my case but after realizing they were 3 pin and this is bad, I panic purchased Noctua NF-F12 PWM, 4-Pin Premium Quiet Fan (120mm). However when I tried to install them into the case, the case screws wouldn't fit properly and the screws that came with the fans popped past the case inserts. So I gave up. Then reading the manual I realized these were meant to replace CPU cooler/AIO fans. However, some reviews seem to imply that people are using them as case fans. Am I confused? Am I reading about a different model? Thanks!

Edit: for reference, the Antec fans fit with both the Antec screws and case screws.

Edit#2: NO LONGER CORRECT: I can install the Noctua fans by removing the rubber attachments on the corner. I'm not sure if that means they're meant for case fan use or if I'm forcing it where it doesn't belong. Thanks.

 

[Paperdoc]

Yes, you are a bit confused. First, the mounting systems for fans all are pretty much the same. There is NO difference between case vent fans, fans to be mounted on a CPU cooler, and Rad fans as far as mounting is concerned. Of course, if a fan has extra rubber vibration pads on its corners that add a little thickness, that MIGHT affect how long the mounting screws need to be. But also, bear in mind how those screws are supposed to be used. You place the fan against the mounting plate and insert a screw from the metal MOUNTING PLATE side, then turn the self-tapping screw into the hole bored in the plastic fan frame corner. These are stiff when you first install them because the screw is cutting new threads into the bored hole in the plastic. It is better to leave those soft rubber pads around the corners to reduce the transmission of vibration and noise from the fan to your case.

The difference between case ventilation and CPU cooling applications is in the fan blade design, not in the frame. The most important performance item for a fan is Air Flow rate. Also realize that the actual air flow a fan can produce depends on the resistance to air flow it is pushing against - that is, Backpressure. There are two basic classes of fan designs. One type is optimized for max air flow against very little backpressure, and that's ideal for case ventilation. The other is designed to force air flow against higher backpressures, and that is best for finned heatsinks and radiators that offer more resistance to air flow. These latter typically deliver slightly less air flow at any speed than an "Air Flow" fan can against a SMALL backpressure, but against the typical backpressure from a radiator the "Pressure Fans" deliver MORE air flow. That is the point people are debating when they say which location the fan should be used.

Your Noctua NF-F12 PWM fan at its max speed (1500 rpm) can produce max airflow of 93.4 m³/hr against no backpressure at all, and less airflow at more backpressure, up until it basically cannot force any air to flow through a backpressure of 2.61 mm water or greater. At full speed it generates noise at 22.4 dBA. Now, within that product line, the "ideal" fan might be their model NF-S12A PWM, which can do 107.5 m³/hr max airflow (more) at no backpressure, but quits forcing air at a backpressure of 1.19 mm water (much less, but suited to cases). To do that, its max speed is only 1200 rpm and that generates noise at 17.8 dBA (quieter). Those are the specs, and why the latter model is slightly better suited to case ventilation. BUT the ones you do HAVE will most certainly do the cooling job you need. All that will mean is your system under automatic fan sped control (based on case temperature) by the mobo will run your fans slightly faster to achieve the required air flow, and that will mean very slightly more noise than if you had bought the "ideal" ones.

So, don't worry, be happy. Use the fans you have, and see if you can mount them correctly including the rubber noise reducers.

Just a small note of caution. I always recommend you use the mobo headers for fans and let them do their automatic fan control job that is the default setting. Noctua ships their fans with little "LNA Adapters" that are small resistors you can insert into the fan's connector to reduce noise. Well, they do that by reducing the voltage supplied to your fan, and thus its speed and air flow, reducing the cooling they produce. These are really useful ONLY when you can NOT connect your fan to a mobo header and are using a direct connection to a PSU 12 VDC supply; then the LNA is your way to reduce fan speed when it does not need to be full speed. But when you are using the mobo header and its automatic control system, the LNA just fouls that all up, so do NOT use those little things.

 

[Send_Help]

Thank you for all of your help, seriously. Noctua caused me so many headaches- I'm worried I crushed my cpu with its spring based mounting. So I'm switching to AIO/radiator. Thank you for your detailed answers.

Edit: just as a side note, both my antec fans and now an AIO radiator attached to my case with no problem but the noctuas just wouldn't. Again, thanks for everything.

 

[Paperdoc]

You're welcome, and I'm glad you have found a good dolution. Thanks for Best Answer.