Inky
Beginner
Sorry for the double post chaps but this sounded similar to what you were discussing.I had a similar problem with fan noise but was worried about the fan warning and decided to see what I could do about it.
Initially I purchased an alternative 80x7.5mm 24v fan 2 pin fan since
I struggled to find a 3 pin fan in the UK. My idea was to leave the
original fan behind the new one so it would still spin and give the
signal required - but it didn't! So that was a bust. The fan warning
still came on. The new fan was too loud anyway despite being advertised
as a quiet fan.
My next idea was to use a resistor in series to lower the voltage to the
fan and thus the noise. I had a few Noctua NA-RC10 cables lying around
so stripped the wires and added these in series. They contain 51 ohm
resistors (I wasn't sure of the brand but every other 51 ohm resistor I
looked at had a voltage rating in the hundreds). When you calculate it
with the 24v fan at 0.1A it works out as a reduction to around 19.7v
overall. This dropped the noise by about 20%!
I figured the warning will have a fan speed cut off at some point but I'm not sure quite what this was.
I also replaced the original metal screws with the rubber kind to help vibration. Which cut the noise by another 10% or so. NB these were the really cheap silicon ones my Noctua ones didn't fit.
So now the Vewlix isn't silent but it sounds more like a desktop PC than
a jet engine. I suspect you could increase the resistor value higher
and drop the speed more, but I wasn't sure of the exact value and had
those Noctua NA-RC10 cables lying around which I figured means they've
been tested in a similar situation and I could make a tidy job of it.
I think the best solution would be a pair of Noctua 12v 80x15mm fans
with rubber screws put in series with a voltage regulator or resistors
in series - trouble is the speed may drop so low as to set of the fan
warning?
Anyway hope this all helps anyone considering some thing similar in the
future. I don't make any claim to the safety or longevity of this set-up
there's plenty of people who say a set-up is bad for your power
supply...I guess time will tell.
For now I'm much happier with the fans.