Wow. That’s all I can say about the Nexus 120mm Real Silent Case Fan.
I’ve replaced a few computers in the last two months and have been reshuffling hardware around the office. I decided that my MWave Pentium D 830 PC (vintage mid-2005), which had previously been my main production system, would now take over server duties: shared files, web apps on an intranet, and virtual machines via Virtual Server 2005 R2. In the process of making the switch I noticed that the noise level of this system had become unacceptable, and it was especially noticeable in its new location. Even with the door shut, I could hear this PC running from 10 feet down the hallway. A little careful listening suggested that the bulk of the noise was coming from a single case fan in the back. The power supply and CPU fans were both inoffensive.
I decided to replace the case fan with the Real Silent fan ($12.99 from endpcnoise.com; the total with shipping came to around $20).
It took just a few minutes to replace the fan. Undo four screws, swap out old fan, use same screws to secure new fan. The power and fan connectors were easily accessible and the plugs on the replacement fan matched the original.
When I turned the system back on, I wasn’t expecting a huge difference. But the change has been profound. When I place my hand in front of the fan’s exhaust, I can feel warm air being pulled out of the case, but I can’t hear the fan at all. I’m sure the noise level is measurable, but it’s crossed well to the good side of the noise fatigue line and blends comfortably into the background.
Generic case fans are especially susceptible to this sort of deterioration. Over time, they seem to get louder and louder. Which is why this sort of replacement can be so effective. Next up, I’ll give the same treatment to a three-year-old Dell PowerEdge server that’s buzzing front and back. If it has the same effect, I’ll have a Real Silent office for the first time in years.
Ed Bott (@ wordpress.com) 
Yeah, these are pretty good fans.
It only takes a little muck to settle on the blades of a fan to knacker it though. It throws the bearing out of balance and that’s what causes the wear to start. I find that giving the blades a careful wipe over with anti-static solution like STATICIDE helps prolong life, as does fitting fan filters.
Enjoy the quiet office!
I built a quiet PC using (among other components) those Nexus fans. At the time I built it, I literally had to touch it to see if it was running, it was so quiet; 18 months later, it’s gotten a bit louder (it’s audible), but is still at a whisper level.
If you just now discovered those fans, you haven’t been to SilentPCRview.com. They are a bit whacko, but well worth it.
I replaced my case’s fans with Vantec “Stealth” fans a couple of years ago, and the difference was considerable. Later I was looking at the specs and found that the Stealth brand fans run at a lower speed than stock fans. If I remember right it was about 3000 RPM vs about 5000 RPM.
It turns out you can make any fan quieter simply by running it slower. My aerenautical engineer friends tell me that this is because most of the noise from a fan is cause by the air flow over the blades, not by bearing noise. Slow down the fan, reduce the airflow, reduce the noise.
Last year I moved my main PC (a dual-Xeon setup with lots of fans) into an Antec Performance One P180 case. It comes with three-position switches for the main case fans, letting you tune for the right balance of airflow vs noise.
The biggest improvement I ever made in my PC’s noise was to use a BIOS that can regulate the CPU fans and case fans based on system temperature. When the PC comes on, the fans all run at top speed and the box howls like a wind tunnel, but it quickly begins to ramp down and by the time the OS has booted the system is whisper quiet.