Hi to Everyone,
I have a smps from Meanwell that i like very much Unfortunately its fan runs very fast from the start and it is very noisy (pic attached)
I wonder what would be the best approach to follow in order to tame the noise
Can i mount it reversed ? i guess that know it pushes the air inside and this could be a reason of the noise ?
I understand there are also silent fans ?
Just taking it out worries me.
Any kind and welcome suggestion ? as i said above this is only the real issue i have with an excellent smps.
Should i move instead to a different model ? i am very willing to do it.
I am using 24VDC for some little digital amps that i am testing
Thanks a lot to everyone.
Kind regards, gino
I have a smps from Meanwell that i like very much Unfortunately its fan runs very fast from the start and it is very noisy (pic attached)
I wonder what would be the best approach to follow in order to tame the noise
Can i mount it reversed ? i guess that know it pushes the air inside and this could be a reason of the noise ?
I understand there are also silent fans ?
Just taking it out worries me.
Any kind and welcome suggestion ? as i said above this is only the real issue i have with an excellent smps.
Should i move instead to a different model ? i am very willing to do it.
I am using 24VDC for some little digital amps that i am testing
Thanks a lot to everyone.
Kind regards, gino
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Small fans are noisier than large ones.
Running a fan at a lower speed makes either ones much quieter.
There is no need for a hurricane flow, I gentle breeze is effective right away.
On a PC case with two case fans, I rewired their 12V normal supply to 5V, an easy mod at their Molex connector. All, I need is enough air movement to break eventual hot spots.
Now this PC is perfectly quiet.
Running a fan at a lower speed makes either ones much quieter.
There is no need for a hurricane flow, I gentle breeze is effective right away.
On a PC case with two case fans, I rewired their 12V normal supply to 5V, an easy mod at their Molex connector. All, I need is enough air movement to break eventual hot spots.
Now this PC is perfectly quiet.
Unfortunately there is no such thing as a silent fan as the air has to be moved.
I would look for a quieter fan; Axial Fans | RS Components
I would look for a quieter fan; Axial Fans | RS Components
Hi thanks a lot. I suspected that noise is related to the rotating speed. I wonder if reducing the voltage to the fan can slow it down. They sell small dc-dc converters that can decrease continuously the voltage to the fan
On the fan i see 12VDC- 0.13A
I will try one of those small variable dc-dc step-down converter soon
I would prefer to have a gentle flow than too much of it or no flow at all.
I guess that if they have decided to put a fan in there must be a reason.
Thanks a lot.
Hi ! thanks for the very kind and valuable advice. Actually i am thinking of two options
1) reduce in some way the rotating speed of the original one
2) install a bigger low profile 12VDC very silent fan and make some additional holes in the upper lid. This is more complex but also should improve hugely the ventilation inside the enclosure. The lid is very thin. Drilling it should not be a big issue
As i said i am very happy with this smps fan noise aside. It makes my little amps sound almost decent. 🙂
Hi ! i bought some of these to decrease the 12VDC to the fan ... just a try
1pcs DC Convertitore lineare buck Step Down lm317 basso ripple Modulo Alimentatore | eBay
I am so convinced about the high quality of this smps (great respect for the Meanwell brand) that i am even willing to buy a completely new enclosure that would allow to put a mighty but silent fan in it. Of course i hope this will not be necessary.
In order to isolate the converter from the metallic chassis i am thinking to use a big section heat shrink tubing Will the heat from a hairdryer be enough to shrink the tubing ? 🙄 I do not want to damage the plastic parts on the board
1pcs DC Convertitore lineare buck Step Down lm317 basso ripple Modulo Alimentatore | eBay
I am so convinced about the high quality of this smps (great respect for the Meanwell brand) that i am even willing to buy a completely new enclosure that would allow to put a mighty but silent fan in it. Of course i hope this will not be necessary.
In order to isolate the converter from the metallic chassis i am thinking to use a big section heat shrink tubing Will the heat from a hairdryer be enough to shrink the tubing ? 🙄 I do not want to damage the plastic parts on the board
Adding a simple zener diode in series with those fans can lower speed/noise easily.
For a 12 volt fan, try a 6 volt zener, or select one which gives the intended speed/airflow.
And clean the blades - the dirt on them affects noise and efficiency.
For a 12 volt fan, try a 6 volt zener, or select one which gives the intended speed/airflow.
And clean the blades - the dirt on them affects noise and efficiency.
Hi ! thanks a lot for the very kind and helpful advice. Problem is that i do not know how low i can go with the supply voltage to the fan. The regulators i bought are adjustable
Thanks ! actually i did not expect this dirt inside. I have a further question. What kind of impact the direction of air flow (i.e. inside-out or outside-in) will have both on cooling and noise ? 😕
I prefer to extract hot air from the inside if this is possible
There are advocates for "out" and others swear by "in".
I think it doesn't make much difference and to make sure to be a winner, I have two fans at opposite sides of the case, one that push, the other that pulls. Air moving through is the best.
Experimenting with variable speed you will see there is a very significant difference from no air flow to just a little, then not that much from fast to a fastest tornado.
I think it doesn't make much difference and to make sure to be a winner, I have two fans at opposite sides of the case, one that push, the other that pulls. Air moving through is the best.
Experimenting with variable speed you will see there is a very significant difference from no air flow to just a little, then not that much from fast to a fastest tornado.
I would not do this. I understand the converter would be thermally isolated....A best way to ruin cooling.
Shrinking with an air dryier should work fine.
I use a simple circuit to vary the fan voltage and speed like this : Modular active 3 way - work in progress
Makes it easy to find the speed that is quiet enough for you.
Makes it easy to find the speed that is quiet enough for you.
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Most PC users trying to silence fans seem to think that the the noise
is generated by the vibrating fan coupling to the computer and not
the air motion.They use these rubber dampers to reduce the coupling.
120mm Fan Silencers | Page 1 | Sort By: Product Title A-Z - FrozenCPU.com
Just an example.
Search for fan muffler.
is generated by the vibrating fan coupling to the computer and not
the air motion.They use these rubber dampers to reduce the coupling.
120mm Fan Silencers | Page 1 | Sort By: Product Title A-Z - FrozenCPU.com
Just an example.
Search for fan muffler.
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Bear in mind hat the protection grille construction also contributes to the noise. Test without it first.
Thank you very much indeed. You have very kindly answered all my questions.
I think in general heatsinks are a big issue. They are extremely expensive and huge in size.
With fans it is possible to go with much smaller heatsinks so the fans topic is very interesting to me.
They are the norm in pro amps and almost never found in home amps. With the results that i understand many home amps shut down for overheating when pushed hard 🙂
Thanks again, Kind regards, gino
I run fans on lower voltage than they are specified. Less air flow always results in less noise. Some fans can run on half the voltage, and still provide adequate cooling. This off course needs to be tested and optimized.
I take fan and power it with regulated dc supply, and start lowering the voltage. At one point, it will have hard time to start, thats too low, so I back up with voltage. For each fan I find its comfortable low voltage, at which it works reliably, quietly and still provides enough cooling.
thank you very much indeed. I will study where to place something like this.
I am waiting to receive a voltage regulator i ordered
Hi ! thanks a lot for the advice. Just to be sure to understand ... the source of noise is the air motion isn't it ? and actually reducing the motion reduces the noise 🙄
Thanks for the advice. But i would like to use the psu with the grille on.
I have to lower the fan speed for sure. And i will do in the next days.
this is exactly what i am thinking to do So i bought some voltage regulators
Would a cap put across the voltage rails help at the start ? like a 1000uF cap ?
A safe bet is running those PC style fans at half-voltage, AKA 12V fans around 6V.
Inserting a series 6V Zener in their line will bring about that easily.
The usual result is adequate airflow and a nice quiet fan.
The easiest solution, if not the cheapest, would be to replace the power supply with a
different, lower current Meanwell with an open, mesh type top surface. These have no fans. If heat is a problem, you could then use a small silent PC on top of the supply to move air through the supply. This solution is only workable if you have lower current requirements than what would require the LRS-350. This is what I did.
If you need the 350, the only workable solution would be to open the case and disable or remove the existing very loud fan, drill some vent holes in the sides and bottom of the Meanwell case, and place a small silent PC fan over the existing fan outlet to suck air through the supply. Many of those fans, including the Noctua brand that are popular here, include optional wiring harnesses that allow you to reduce speed to below the threshold of audibility, even if your ears are just inches from them.
different, lower current Meanwell with an open, mesh type top surface. These have no fans. If heat is a problem, you could then use a small silent PC on top of the supply to move air through the supply. This solution is only workable if you have lower current requirements than what would require the LRS-350. This is what I did.
If you need the 350, the only workable solution would be to open the case and disable or remove the existing very loud fan, drill some vent holes in the sides and bottom of the Meanwell case, and place a small silent PC fan over the existing fan outlet to suck air through the supply. Many of those fans, including the Noctua brand that are popular here, include optional wiring harnesses that allow you to reduce speed to below the threshold of audibility, even if your ears are just inches from them.
Another idea, that I used a few years back is to remove the fan and use a single larger fan for the case + power supply cooling. This pic is for a Meanwell 36VDC 350W PS. The internal fan is removed and cable is extended to the enclosure exhaust opening and a larger fan (80mm shown). Then a simple plenum is added to control the air intake to the PS and out the PS exhaust port to the case where the fan vents it out. Only works if you have a closed box with one air intake and one exhaust. This was still louder than I wanted so I added the speed control mentioned earlier. Reducing the speed to control noise, via many methods mentioned already, gives the best result.
My current project uses a similar strategy (one intake, one exhaust) now but I'm using an open mesh PS design described by ^@tubesguy.
My current project uses a similar strategy (one intake, one exhaust) now but I'm using an open mesh PS design described by ^@tubesguy.
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Hi thanks but sorry i am ignorant. You say that if i put a 6V zener on the positive wire in series with the fan it gets only 6V ? just that ?
Speaking of zeners i know that they are used very commonly as voltage regulator is a slightly more complex schema
