4.72inch 4Pin

Okay, so, I've been using this thing for about a year and here are my thoughts. In order to use this, I bought a barrel-jack/fan connector and an adjustable fan controller that fits said barrel jack connector. Upon opening the box the first thing that you notice is the sheer girth of this unit. I mean, it feels much heavier than it should. The build quality is amazing and it runs like a top. at low speed its nearly silent and cools my mid-tower cpu case and heat-sink to a comfy 45c. I want whoever reads this to understand, I don't have a fan on my cpu heat-sink, this thing is connected to the front inside top of my case so as to suck fresh air in and blow it. It blows enough air, from that position to not only cool my heat-sink on its LOWEST setting but to also hit the fan in the back of the case. On medium, the fan sounds like what I imagine a duck hitting a airplanes turbine hears before it becomes meat shrapnel. It's just, Incredibly loud. Like, you can hear it 30+ feet away at half speed. The cooling performance though, matches the noise. I'm able to drop from 71c post Vulcan shader render to 42c in 20 seconds at half speed. Now comes the complicated part. Depending on the heatsink you use, There's little to no point in using this thing past half speed. Let me explain. The heatink can only throw so much heat, and this fan moves air so fast, after half speed, it reaches a point where it just doesn't remove any more. I am able to hold a paper towel to a wall at 3 feet from the back of my case at the fans full speed though lmao. Bottom line is, It's stupid, overkill, and I'm in love, buy three. Just don't forget the adapter and external fan controller, this may kill your power supply.

Amazing air output and noise level! I found operating it at a low 3-6 watts, it is moving as much air as most of my other 120mm fans. Crank it up to full power of 20+ watts and it's like facing a 30+ mph headwind. Thankfully I purchased a speed control to go with this. Unless you are mounting this fan inside a sound proof chamber you'll definitely need one to restrain the noise. I purchased this fan for cooling under my tractor canopy so the noise isn't that bad compared with the tractor diesel engine spinning 2500rpm. Most of the time I'm using the speed control at about 1/2 of maximum. But it's wonderful to crank it up when the outside temps are getting high. Size is correct match for 120mm mounting. The speed control I used is 4 pin version so fan connected right up. I haven't had any problems with operation. Get a speed control that permits setting a minimum speed also helps. Overall I am very, very pleased. I've bought several other Wathai fans and this one is just as well built as the others. I will definitely to buy Wathai fans.

First of all, they can be very very loud if set to the highest level of speed. This is exactly what I wanted to replace the jet flow fan cases I got originally for my pc many many years ago. You can adjust the speed using the fan control in bios or any other fan control program. I have mine set to manual because trust me if I have it set to cpu temp it sounds like it will take off...lol. Anyway, I can feel the air move and it doing much much better than any regular cpu fan. These are server fans and they can move the air. I think the manufacturers setting is off because I think it moves more than they say. Which is great for me and i have them set at 35% in the front and 45% in the back and the sound is okay. I am very very happy with my purchase. I might end up ordering one more but for now these are fine

Sound is obviously going to be a problem @3k+ rpms. I really don't care. I always use headphones. I have five of these. Three for intake on a 360mm Radiator. Two for exhaust. Definitely dropped my thermals. I run them @4k rpms when production/creation. Keeps my 5950x below 70c under extreme loads. Whilst overclocking every aspect of my computer. I'd suggest these to anyone if your don't mind the sound. I also purchased sleeved pwm cables. So I didn't see the ketchup and mustard colors. Everything I've ordered has worked flawlessly from 1k rpm to 5k rpm. No issues. Extreme airflow.

These things are serious. I run them with an owltree 12v 4pin controller. Out of the box I stood them up on my desk to test them and they pushed so much air, they pushed themselves across the desk. They aren't quiet at all, but I need them to cool. Very pleased.

Moves a lot of air for its size but is noisy. Doesn’t use as much power as I expected.

It's like a jet engine; both in good ways and bad. It's incredibly loud, mirroring the sounds similar to an overhead airplane taking off. Measured 74 DB on the decibel reader. CFM reading averaged about 178 with just the provided fan grill. It does put out a good amount of air, will blow papers off a desk across the room, but the noise is just overkill. Noise is about on par with my bounce house blower fan. Good price for performance if you have hearing protection though.

First, this "12V" dc fan's manual casually mentions that it can be damaged if run more than 20% above 12V rated voltage. It's *remarkably* thoughtful to design it to survive at the lead-acid car battery voltage 14.4V since most people I know call a cigarette lighter plug "12v." Now I don't need to add voltage regulation before hooking it up to to my car (or my 10 x AA Ni–MH power pack that runs between 13v and 14v)! They even include instructions on how to swap the wires in their plug if you have different polarity on your device. (I also bought the "Dual Ball Centrifugal Fan High Airflow" model from the same manufacturer, and it's equally superb, but as a "reasonable quietness outweighs sheer air flow" alternative, which also works beautifully even mounted flat against a solid surface.) I *almost* wired a PWM controller sharing the same power source, but I was in a rush so I used a simple power PWM controller as the power source instead of a constant 12V with PWM signaling speed and, while it doesn't get the fan below 50% power, that level isn't terrible if you have something else making noise in the room, so in a pinch that's an option for many projects using the fan. For those who are less comfortable with the details of electrical engineering the my amatuer self (but somehow have a 12v pulse-width modulation power regulator hanging around?), I should note that I get extremely non-linear scaling behavior using it (cut-in around 5% to 10% pulse width), ramp up to about 80% fan speed at about 25% pulse width, and the remainder of the speed is spread over the last 75% of the pulse width. As I write this, I realize the relationship is probably roughly logarithmic starting at the cut-in and I suspect (since I don't want to rip apart one of my two favorite fans of all time) there's a cap or inductor or something smoothing out my pulses before they hit the brushless motor controller IC so it's just seeing a very dirty reduced input voltage when I have a PWM wired in. At 100% speed, it's about as annoying as a vacuum cleaner (not nearly as loud, but much more piercing and distinct overtones). At half speed, the annoyance is about the same as an air window conditioner unit. I cranked it up to 100% and verified the advertised speed and discovered as some (possibly useful) characteristics. I recorded the sound of the fan and found the fundamental resonant frequency is 600Hz, which divided by 7 for the seven blades making each revolution, is about 85 Hz, or (multiplied by 60 to convert Hz to RPM is) 3600 RPM. If you are still reading, you must be looking for something wrong with it. Sorry, I can't find a single thing to complain about. :-)

Extrêmement puissant et donc bruyant à vitesse élevée. Très efficace

Wow.... Amazing fan!

Update: I've now had 3 of these fans fail in the same way only a few hundred hours after being put into service. They will fail to reach full speed and start making a noise. Eventually they will jam completely. After dissecting all 3 I found a failed capacitor can jammed between the rotor and the stator coils. Removing the can and reassembling (without replacing the capacitor) the fans will work at partial speed but not the full 5300 RPM. I'm reducing my rating to 1 star as these fans are NOT reliable and will fail prematurely regardless of the operating conditions. Whether it's a bad batch of capacitors or a bad design, I can't say, but a failed capacitor causing mechanical failure of the fan after only a few hours in service is unacceptable. Original review: I have a small single room ventilation system which was previously using Noctua industrial 3000 RPM fans. I bought two of these to try as upgrades, one for intake and one for exhaust in an HRV type setup. The exhaust fan seems OK after 2 weeks, but the intake (installed in a bottom to top airflow configuration taking outside air in via a filter) started making awful noises after about 48 hours and seized altogether after 3 days. I removed it and got it spinning again on its edge, reinstalled it, and within 2 hours it seized again. It’s seen air temperatures between about -2C and 10C, and would see a range from -35C to about 40C in that installed position, which the Noctua Industrial fan has handled just fine for over 2 years. So I’m rather disappointed, to say the least. I tried replacing the lubricant with some multigrade oil to see if this will help. As I said, the performance is exciting, but I can’t really stomach the prospect reliability issues in this system.

In accurate size - it’s actually 92-93mm not 120