hey guys! this board is always a real treat but im only here

>>1189619
electrical motor can make a quiet hum, but most of the noise is in the bearings.
the motor can make noise if the bearings/bushings in the motor, or from the carbon brushes if it's not a brushless motor.
fans also can get loud if they hit a big piece of dust and chip or bend, so they're unbalanced.

Usually the best quiet design is water cooled and a very quiet external pump motor that can be heavily insulated. (which you can't really do with fans without screwing up the airflow.

Sound propogates through air. Noisy fans are usually because of turbulent air coming of the fan blades themselves. There isn't much you can do to change the shape of the blade and make it quieter.

Even the most expensive fan blades only seem to have little notches cut from the trailing edge. They are better than the cheapos but they still make noise at full tilt. Less noise also means less airflow.

Go buy better fans of you want a quieter PC

>>1189619
Simple.

Buy brushless 120mm fans and instal them with a speed controller.

Choke it down to 7-9 volts instead of 12 volts.

Better airflow and quieter.

Alternatively you can do like i did and just throw a heater core from a dodge durango ina deep freeze and hide a pump behind it in the other room. Mix 100% antifreeze 50/50 with distilled water.

Not sure if antifreeze leak would fuck my shit uo but its an older system so idgaf

Apart from the fans themselves, look at attachment points, case integrity/airflow and getting relatively unobstructed airflow to/from fans. Anything the fan does, no matter how minimal, can still propagate to the rest of your system. I have a front door on my case, and closing it slightly helps reduce transmitted sound.

If you really want to redesign a fan for complete silence, set your bench/standard, such as 120mm, motor rpm, 12v, then work from there. The noise is a combination of bearing, turbulence, vibration, and propagation, and perhaps many others I have missed.

I'm starting to question your knowledge because you didn't post any of it. Start by understanding the problem, have a control, look for variables, understand the variables, work with those variables, approach from multiple angles, culminate, produce, test, repeat until outcome is desirable. Your results are as good as your methodology. If you say that I'm blaming the tools, then I'm holding the chisel the other way around.

>>1189619
Buy a noctua fan

Use fire to pull air through the case

stick whole computer in oil tank

>>1189619
>computer manufacturers
REEEEEEEEEEEEEEEE
Stop buying prebuilts.

Buy a bigger case that uses 120mm fans and 120mm fans.
Buy a bigger heatsink for your cpu. or fuck around with a peltier plate.
Fucking with custom cooling for your gpu isn't worth it. Just go for a design with passive cooling


>>1189773
The bearings don't make noise unless they're dying/dead. Most of the noise is airflow.

>you can't really do with fans without screwing up the airflow.
Not true.


>>1189800
>Buy brushless 120mm fans and instal them with a speed controller. Choke it down to 7-9 volts instead of 12 volts.
Or... Get a motherboard made in the past 5 years.

>Not sure if antifreeze leak would fuck my shit uo but its an older system so idgaf
Why didn't you just use dried alcohol? It's non-conductive, and they make alcohol inert orings.

>>1190159
Dried alchahol. Nice :)

Thanks anon.

And sorry. I havent had internet till last month. Been a decade in the sticks. Dont meet the minimum requirements to play world of warcraft.

Building $3,000 battlestation soon as i fix my shitty house next month.

Its gonna be yuge.

Sheet metal 100 pound pc case when!

>>1189778
>There isn't much you can do to change the shape of the blade and make it quieter.
Sure there is. Scimitar blades are quieter. Scalloped trailing edges can reduce noise. Tip geometry can have a huge impact on noise, especially with unshrouded or loosely-shrouded fans. Irregular blade spacing can help break up and "whiten" resonant noise (assuming measures are taken to preserve balance, of course).