It seems like all the engineering effort from the design team has paid off. When you see the lengths that Noctua taken to inform the consumer, you expect the product to be quiet – and it is.
The noise from the FLX at 12v is audible but it seems to be the sound of the air hitting the struts holding the motor rather than any whine or motor noise. When you fit the 1050rpm NA-RC10 adapter it drops to barely audible; when you use the NA-RC11 noise adapter it gets pretty quiet indeed. We struggled to hear it at all in an enclosed chassis – there was perhaps the slightest sound of moving air in an otherwise noiseless room.
The ULN model is, for all intents and purposes, silent. There is a fan moving at 800 – 650rpm so it’s not 100% silent if you have your ear right near it but in an enclosed case, we couldn’t hear it from a metre away with the NH-RC11 noise adapter fitted. Note that for a minute or so, we stopped all of the other fans in the test rig to try to hear it in isolation.
We also plugged both fans into a molex connector and sat them on our desk so we could really listen close to them. We used the noise adapters to see the difference and were looking out for any ticking, buzzing, whining or whistling. In the end, we came to the conclusion that the fan mechanism is as smooth as you could ask for. There is wind noise as the airflow hits the 4 mounting struts that radiate from the centre of the fan but this noise is constant and not dominant. Once the blades are slowed down to about 800rpm, it was almost impossible for us to hear the unit.
As usual for PWM fans, we used the default ASUS Fan Xpert profile. When idle, we could not distinguish this fan from any other ambient noise in the room – case open or closed. Under load and at 12v, the noise was audible but as per the NF-A14, the noise seemed to be moving air rather than any motor related noise.
We also added the 120mm NF-F12 to the front of the NH-D14 cooler to test it in a fully PWM mode. We found that in all tests, the NF-F12 was the louder fan and the A15 was not clearly audible over the F12 – in other words, it was consistently the least audible fan in our test bench. In this configuration, the modified NH-D14 cooler was virtually silent at idle and noticeable when running Prime95. The thermal results are impressive and we doubt that the average user would notice this configuration over ambient noise in general day to day use or gaming.
Which one to choose?
When faced with 3 different 140mm offerings from Noctua, you could be forgiven if you felt spoilt for choice.
The outgoing NF-P14 with the round frame is the standard fan in the NH-D14, NH-C14, and C12 SE14. It’s quiet and has mounting holes for both 120mm and 140mm fan mounts. It will be very interesting to see what Noctua produce next as it stands to reason with the NF-P14 being replaced by the NF-A14 and NF-A15, these CPU coolers could be due for a facelift. Based on what we have seen with the NH-L12 and NH-L9i recently, we are speculating that a refresh of these coolers will see the introduction of PWM 140mm and 120mm fans to enhanced generations of the Noctua performance heat sinks.
The NF-A15 has a different frame again and is built using a PWM fan speed controller. The frame means that it won’t fit in many 140mm case fan spaces but it is designed for heat sinks like the NH-D14. See our review HERE.
When looking at the NF-A14 models it’s important to note that the NF-A14 ULN tops out where the FLX starts in terms of rpm, static pressure, airflow and noise. The ULN has half of the power draw of the FLX and is virtually silent.
The NF-A14 FLX would be our choice of the 2 models for normal use with radiators or heat sinks due to the higher static pressure configurations. If you had a need for serious airflow intake or exhaust, then this may also be a better option as case fan than the ULN.
The ULN is perfect for scenarios where you need to move air through your case but don’t want any noise – like a HTPC or audio workstation. Our Stryker build for example has a GTX670 OC graphics card with a Gigabyte Windforce 3x cooler that dumps the hot air inside the case. We don’t need to push the air out at high speed to keep everything cool so the ULN will be fine. On our Fractal R3 build, we could use 2 of the A14 ULN units in the roof to help exhaust the air quietly and still achieve more than adequate airflow without any noticeable noise.
If you need static pressure or high airflow, we recommend that you look at the specifications to see if the trade-off between noise and performance is something you can live with in your build. The NF-A14 series fans are quiet but they are also slower than some of the other options available.
Conclusion and Final Thoughts
Many gamers are building their rigs with windows, bling, LEDs and other funky kit. The Noctua colour scheme doesn’t exactly go with red, green or blue case lighting let alone some crazy UV. Whilst the beige and burgundy scream “Build Quality” and “Low noise” to us, this isn’t the same for all system builders. If you are building a pimped out setup with funky lighting, window panels and possibly a custom water loop – these don’t exactly look “Badass” nor do they light up or come in different colours. That said, the Noctua trademark colours don’t look too out of place when matched with an ASUS Sabre tooth motherboard and we’ve seen a couple of rigs on the forums where builders have matched them in nicely.
As per all of our previous Noctual reviews, the build quality, accessories and performance of the NH-A14 fans we received were in line with the asking price of AU$29. It’s true that there are cheaper fans available that move more air at higher speeds. – so that’s something for the consumer to weigh up depending on the requirement. I’m often asked if I think the ~$10 premium that we are asked to pay for Noctua fans is worth it. Based on what you get in the box and how quiet these fans are – absolutely, without a doubt. The interesting thing here is that we are not sure if the average system builder will need the 30cm extension cable or voltage reducer (especially on the A15) but they are a nice touch and of good quality.
Another thing to remember that a cheap fan controller for your non-PWM 140mm CPU cooler will set you back about the same price as a NF-A15. Personally, I’d prefer to have less cables and an automatic fan speed/temperature controller via PWM.
The Noctua NH-D14 costs around $85, so to then pay another $29 for an A15 and then $29 more for an F12 would make your new cooling solution cost about $143 – quiet but very expensive and probably not good value. On the other hand, if you already have a D14 and it’s the loudest part of your rig, a $60 upgrade to it doesn’t seem so bad if you are obsessive about having a quiet PC.
For silence freaks like myself who are happy to trade a few degrees for a quiet gaming platform, the NF-A14 series are great and I highly recommend them if they meet your airflow requirements.
If you are building a HTPC or DIY Steam Box and want consistent airflow from a 140mm case fan that you won’t hear over movies then grab the A14 ULN – hands down.
In our eyes, the NF-A15 has taken the NH-D14 (that we would argue was already very good), to a new performance/noise ratio. If you have a 140mm CPU cooler and it’s fan is either is not PWM or is louder than you are comfortable with, then the A15 would be well worth your money – just check the specs and make sure it will fit first.
These fans represent the continual evolution of the Noctua product line. As impressive and exciting as these fans are, we are even more interested in the coolers that will see the A15 and F12 fitted as standard in the future.
All “Noctua” fan and box images courtesy of Noctua