Changed noisy fan to turbine , 24 v system, works great and it is quiet for now. We will see for how long, previous /made in china lasted a month only to develop horryfiyng sound , unbearable. I found it hard to get any proper fan that would not be noisy - this turbine does it well.
The turbine is twice the thickness of the previous fan, and seems to respond nicely with onboard speed controller.
Yep, cheap China ones don’t seem to last very long before they make a lot of noise. I have been putting a drop of oil on the bearings under the sticker to keep them going but that is tedious.
Here are my solutions for the regular low profile fans. Very quiet.
The 1053-1211-ND is the quietest.
The 1053-1210-ND is the tiniest bit louder, but still PLENTY quiet, and nearly half the price.
The differences between them are minimal and both are well below the background noise of the motors.
Those are Digikey part numbers.
Unfortunetly, the fan is now noisy again, the bearing is gone, used machine oil too, I am tired of replacing all of those, I am going to install voltage regulator from 24v to 5v and install noctua fan turbine like in prusa. Expensive solution but it will save me time and hassle with changing them over and over again