How to quiten WH S-400-24 power supply? (From wei hao)

I bought a Nunus 24V power supply for 30€ that is actually a Wei Hao S-400-24, so far it looks great although a little big for my kossel mini.
My main problem is fan noise. It's not that loud but quite audible from across the room (much louder than my PC fans). What is a simple solution to reduce the noise? It says on the power supply that the fan is actually temperature controlled, but I'd like to see it switch off when there is only minimal load, or maybe use external cooling.

Should I replace the fan with a more silent one?
Can I add an potentiometer in series to the existing fan or just disable it and use an external, bigger and more silent fan?
Can I adjust the temperature control inside to be silent on low temperatures? I haven't opened it yet.

A simple and cheap solutions for an electronic newbie would be greatly appreciated, thanks for any tips

Sources:
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[www.amazon.de]
[www.ebay.com]

It should be simple enough to replace the fan with a quieter one. I would err on the cautious side and leave it disconnected from the mains for a few hours before opening it to give any high voltages time to dissipate.

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Ralph.Hilton
It should be simple enough to replace the fan with a quieter one. I would err on the cautious side and leave it disconnected from the mains for a few hours before opening it to give any high voltages time to dissipate.

Thanks. It's likely to be a 24V fan though, right? Should I simply add a resistor / potentiometer in series to limit the volt/amps the fan will get?

On a noisy desktop computer fan I placed an 8 inch flexible aluminum ducting commonly used on clothes dryers. Cut it to the length you need, don't obstruct the end. I just let it drop to the floor, the computer was on top of a desk.

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A2
On a noisy desktop computer fan I placed an 8 inch flexible aluminum ducting commonly used on clothes dryers. Cut it to the length you need, don't obstruct the end. I just let it drop to the floor, the computer was on top of a desk.

I guess this leads the noise away from the source. I thought about using something like this for an "exhaust" with an enclosed printer to lead away potential dust particles.

I've also noticed sound coming from the inlet, so I designed myself an inlet-shield and the noise was virtually gone.

Feel the inlet side of your fan, if there is air whirling there, chances are, you might be also getting noise from that.

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http://www.marinusdebeer.nl/

I have the same issue. I use Chinese made switch mode power supplies. I used to have s-350-12 clone which means 12v 350w (29amp) and I switched to s-350-24 (24v 14.6a).

The difference between them is 12v one used to turn the fan on when it was needed. It would kick in for 10-15 seconds every 5-10minutes if I had the heatbed on for more than 30 minutes. 24v ones fan is always and it is loud. Most loud part of my printer.

I considered changing the fan but didn't go with it. I will probably buy a quality one (meanwell) which costs 1.5x of this one but I have no idea how loud it will be.

Please write here if you ever find a good solution.

Thanks for the info Turutk! I'm waiting for new fans to maybe replace it, but I will most probably design an air flow for the whole bottom section of my Kossel Mini so that I'll just disable the fan inside the power supply and have 2 bigger fans cool the electronics, steppers and power supply..

I have a Mean Well SE-600-24, 24v 600w power supply and the fan kicks in 100% as soon as you turn it on and it is very loud.

By the way a good solution would be switching the heatbed to 110/220v and using a fanless power supply.