Noctua NF A4X20 FLX Premium 40X20Mm Review

I bought 2 of these fans to replace the stock fans in the Unifi USG Pro 4 Security Gateway after finding this model recommended for this fan on several forums. The standard fans in the USG Pro 4 are loud, but have an unusually high-pitched sound. The stock fans measured over 55-58dB after only changing the dropout sound by 8dB, however the high pitched tone was removed making the sound much less noticeable. Note. I didn't use either of the two optional noise canceling adapters as I wanted to…

If you own a Ubiquiti USG Pro 4, you know how annoying fans can be when this router is installed in your office or in a place where noise is an issue represents. These Noctua NF-A4x20 FLX fans are the perfect replacement and with the included resistor (lowest voltage) these fans are almost inaudible. My non-scientific test consisted of running the USG with stock fans and then the Noctua fans with my smartphone and the sound meter app placed about 4 inches from the fans. The results don't match…

Bought to replace the super free fan that came with the inverter I recently bought. Installs it with a universal quick wiring adapter. The inverter uses an all-on/all-off fan controller (digital on/off, like a thermostat) and the old fan bearings failed, dragged and overheated within a month of use. Noctua was the first thing I thought of. This is junk! It moves less than half the volume of air as the original (still in my second inverter running alongside). It's quiet, but that doesn't matter…

The fans are quiet, pump some air and the extra ports are nice. The "anti-vibration" mounts on the corners of the fan are just rubber pads glued to low-quality glue. Despite careful assembly, both pads of the two fans we bought fell out. In addition, they are of high quality and a good product. 4 stars for cheap pads and somewhat misleading product description. The product description states that they are useful to replace fans in network equipment. Be careful when choosing the type of fan used

I have been using Noctua fans for many years and have never had a problem with any of their offerings. Although they are not the cheapest in the long run, they are durable and good for continuous operation (CO). There seems to be some confusion surrounding 40mm fans, partly due to the number of offerings from Noctua in the 40mm space and partly due to differences in 40mm fan types. This fan in particular (NF-A4x20 FLX ) is a higher pressure fan designed to force air into a case where air is…

Maybe I was too harsh in my original review. I finally printed a mount where I could use the rubber mounts that came with the fan. Runs much quieter, even at full speed. I probably shouldn't have written a bad review after a failed install. However, it is far from quiet. It might be a little out of whack or something. I expected such an expensive fan not to have noticeable vibrations. It does come with some decent accessories though and if it lasts as long as they say it could be worth the…

Very high quality but very low throughput of 5.5 cfm. I tried them out in an Arista switch to replace my existing powerful but ridiculously noisy Sunon fans. They couldn't get the job done. The processor temperature has exceeded 50 degrees. I changed d to the pwm version which outputs a little more cfm but still not enough. The overall airflow was significantly less and the temperatures increased by 15-25 degrees Celsius. Just not enough air. My solution ended up leaving the original fans and…

Although they are quite expensive for their category and size class, I think they are worth it. I've heard a lot of good things about this brand and I had to replace the two 40mm fans in the Icydock 2.5" 6-sat hot-swap hard drive bay. The fans I replaced were just ordinary crappy low density polyethylene fans that had failed bearings and just generally crappy construction. As an experienced engineer who works at a high level in both several technical fields and information technology, I will…

I recently updated the case for my computer. The new case had significantly quieter fans than my old one. Happy as a peacock, I set about using it, but was interrupted by a high-pitched screech that quickly got on my nerves. A little investigation and I found that the culprit was an off-the-shelf 40mm fan that was helping to cool a component on my motherboard. So I started looking for a replacement. Enter the Noctua fan. I knew about Noctua from a study I did on CPU coolers a few years ago…