Noctua NA-FK1 Redux, Second Fan Upgrade Kit for NH-U12S Redux Cooler

Not much to say here. It improved the cooling on my 9700x about 5C. Not bad for the price, and came with everything needed to install. If I had to critique one thing it would be that the vibration dampeners included are thicker than what came with the cooler.

Just added this thing to my NHu12s Chromax cooler (non Redux) as a second fan, and idle temps are down 6-8 degrees c. Gaming temps are down too. I barely notice any difference in noise levels with the second fan. The cooler seems to not spontaneously ramp up as often it did with one fan. All noticeable good stuff, well worth ~ $16.

I recently purchased this product. I found it to be a great product. It is made sturdy and works well. It is easy to use and looks great. The price was fair and the item was as described in the ad.

So as others have stated I used this as an add on fan for the NH-D15 cooler. My ram was too big to fit the 140mm fan in a push configuration in my meshify C case so I had to set my 2 larger fans in a pull pull configuration as seen in the photos. That was fine for a while with no problems until I upgraded to a 12700k and started to dabble in overclocking it. The cpu puts out a ton of heat when overclocking starts and before my cinebench r23 would quickly push my cpu to 97c and hold steady at that temp until the run completed. After throwing in this fan without changing anything else my temperature dropped the 89c under load with r23 pulling 230 watts with my nh-d15. That’s an incredible 8c drop and way more than I was expecting. Obviously ymmv depending on your use case. I already had 7 fans in my case as it was and this would make 8 and I wasn’t expecting this much of a difference but I think adding the push fan made the difference.The fan itself is incredibly quiet and my system doesn’t sound any louder than it did without it. It seems to be well built and is doing the exact job I was hoping it would do. 10/10 thank you Noctua.I’m considering replacing my other cheaper fans with more of this one because of how quiet it is. No RGB but these fans really do work.

I bought this fan in addition to the NH-U12S cooler, with the single fan the cooler comes with my temps were around 38-45 at idle and around 60-65c under load. With this fan installed in a push-pull configuration, it dropped to around 35-40 at idle and around 50-60 under load. So for $16, it did help to drop my temps a few degrees, which i think is well worth it.It was just as easy to install as the original fan the cooler came with, the only really difference was that the anti vibration pads on this kit were a little thicker than the original fan, but this didn’t make any difference in the install or operation.Noise wise, it is a slight bit louder with this additional fan, but not enough to make a noticeable difference and bother me. It does come with adapters to reduce the noise if you need them, but it’s at the cost of fan speed, so i ended up not using them.Happy with my Noctua products so far, and ill for sure be using them again for any future cooling i may need

Quality fans. Yes they are a little pricey but you know what you’re getting with reliability. Better than those stupid RPG LED fans!

This kit is suppose to be a secondary fan to the NH-U12S Redux Cooler. First, let me say that this is my second Noctua purchase. Their fans and accessories are top notch. They are the ROLEX of the PC Fan industry and don't skimp on quality of their products. The fan upgrade however is not what I expected, the fan blades are entirely different than the one that comes on the Redux cooler. Although, the same size, different blades and the rubber grey sound dampeners are even twice as thick as the fan that comes with the Redux. Not sure if this was a mistake or if Noctua intentionally allowed this variance in product types, but the sound dampener on the upgrade fan makes it very difficult to install and the noise from the second fan is more pronounced which I can tell between the original and upgrade fan.Overall, I am happy with the cooler. It keeps my i5 13600K nice and cool around 27C idle and never peaks above 87C with Cinebench running at 100% multi core test. I have been building alot of custom PC systems over the past 25 years, and this is one of the best air coolers you can buy. I would use this air cooler on i3, i5 and i7 core CPU's only. The i9 12th and 13th run too hot from this air cooler and should be used on a 360mm radiator or AIO cooler at a minimum.

I got this little kit to replace a 140mm fan on a G2 so it would clear my ram. It fit on the G2 and works nicely. No complaints.