NNL DBTB0428B2G 40mm Powerful Cooling Fan for AVC 4028 12V 1A High Speed Server Fans 40 * 40 * 28mm Dual Ball Bearing 4-Wire 4Pin PWM

Good quality.. and fast. But very loud motor

I am using for a diy 12715 peltier cooling plate. As you know the 12715 module can pull 12v and 10-15 amps. It's a monster of a peltier. With a single albeit huge aluminum heat sink, plenty of thermal grease and just this singular fan mounted to a PWM controller, I was able to consistently get the semiconductor stable at around 3° f with only this tiny fan cooling the hot side. That was stable temperature too, not peak. Big difference. I could run that 3° f all day long without the heat overpowering the fan. This was achieved with the fan at full power and the semiconductor pulling around 10 volts and 6 amps. Nowhere near its peak, but impressive as all hell. It's the positive pressure design of the fan with almost a built-in duct because it's so thick as well as the RPMs which I've heard is around 18,000 at full tilt. It's pretty much a cold air hair dryer at full throttle it can blow papers off my desk from across my room which is quite large and actually has some kickback, that's how powerful this fan is. With the setup I mentioned above I was able to achieve about a quarter inch thick layer of ice on the cold side heat sink on the semiconductor within 35 minutes of 6 amps of continuous draw from my 300 watt adjustable power supply. From what this singular fan proved to me, I figure if I order three more and a much bigger heat sink to accommodate, I could run that semiconductor close to full capacity with no cooling issues whatsoever. I thought for sure I'd have to go water cooling for a 12715 but these fans have proved otherwise. They are extremely loud when at full throttle but for my application, which is intermittent fast cooling of electronics on a cold aluminum plate, this is just fine as it runs for very short periods so the turbine like sound of this fan doesn't bother me too much. It is very much a turbine sound though, it's almost ear piercing if left on for a long time, thank God for my Galaxy buds 2 pro with active noise cancellation for the longer sessions because this sucker really screams but it puts out the CFMs to back it up so I don't mind the noise. I've been using it a few times a week for around 3 months now with some sessions having the fan run full throttle for close to 2 hours at a time with absolutely no issues whatsoever, the most I've ever experienced is after about 2 hours the fan will be slightly warm to the touch but that could be from the peltier as well. All in all it was a great buy and it blows just as much air as it did on day one as it does now. It's become old faithful for me and moves easily 5 times the air as my 120 mm 12 volt 0.25 amp fan. Granted the 120 mm is nowhere near as thick so there's no ducting whatsoever and I don't believe it's meant for positive pressure like this is but still these little things seem to be the way to go if you want to successfully cool off a ridiculously angry power-hungry peltier module. Just make sure you get a really high-end heat sink. The heat sink is the most crucial part of any semiconductor setup. Mine is milled from a solid block of aluminum with copper vapor chambers at each corner running down to the hot side ventilation blocks, there are four copper vapor chambers running to two cooling blocks I plan to have two of these fans on each cooling block and I have no doubts I'll be able to run my chip at it's a rated maximum without any overheating issues since I can run it more than half of its capacity with just this single 40x40 fan

Great fans for the R/C hobby! So, great I bought 4 more, for my Traxxas XRT, the fans are paired with a quad mount from HyperFlow Fans. I'm running an 800kv G2 Motor and Max 5 G2 ESC. Just cut the blue and yellow wires and use the black and red wires to run off the reciever, you could wire them up to run off of a 4s lipo, or you could set the up )Not Recommend, in my opinion) to run off of your lipo's balance leads. These things move a lot of air, definitely loud. But!!! Loud is awesome!!! Right?!

First of all. a small fan moving alot of air is going to make alot of noise. Anyone who knows 1U servers knows this. This thing is a mighty little beast. At first I thought it was overrated because it only drew about 650ma at 12v vs the 1000ma (1A) the listing says. usually power draw is directly proportional to speed and therefor airflow and pressure follow suit from there. BUT then I put a tach on this thing and it hit 22,500 RPM!!! its only listed as 18000 RPM.. So to get more speed with less power means this thing is very efficient (at least in that regard). I wish I had a way to measure CFM and static pressure. I dont. But it does move a heck of alot of air for a tiny fan. Also, FYI if its helpful, blue is actually the tach out while yellow is the PWM in. Also the fan will modulate its speed without the PWM lead at all simply by varying voltage from about 4v to 12v will vary fan speed pretty linearly which makes this fan great for analog controls where you dont want to go all the way for PWM (although it will do PWM too if you want!) Great little beast of a thing!!

The fan i was sent was not new. It was a takeoff from a server or a previously used fan. You can see that it was mounted and the screw holes were used on 1 side. Aside from that, it works and moves a decent amount of air, similar to the ones used in my Dell power edge servers.