Noisy power supply

TerryK

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Would it be reasonable to assume these are cheap off-brand supplies? Regardless, My opinion is one or more of the following: supply fan bearings bad or fan is low quality (blade design and/or bearings), no supply fan control (the fan is always full on), rigid mount to base, base is acting as a sound board, and/or the enclosure itself is amplifying the sound (an acoustic resonance as it were).

If these are yours and you are trying to fix the problem I would first replace the fans. Find one with the same mounting size/pattern of course but a fan with a low db noise rating. Also keep an eye on the cfm (air volume throughput: Cubic Feet Per Minute) that is try not to sacrifice cfm to gain lesser noise. Least favorable choice is an acoustic sealed enclosure which will be a pain to deal with.
 

algerdes

Al Gerdes
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Where are your supplies exhausting? Bottom? If so, there may not be enough room for the air to escape as it looks like the supplies are flat on the surface. (This is only on observation of the video and may be off base.) If air can't escape, then the fan blades cavitate. Much noisier than a fan in free air.
 

Jon_101

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Mar 5, 2019
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Where are your supplies exhausting? Bottom? If so, there may not be enough room for the air to escape as it looks like the supplies are flat on the surface. (This is only on observation of the video and may be off base.) If air can't escape, then the fan blades cavitate. Much noisier than a fan in free air.
Exhaust at top left, at time of recording the lid wasn't on ( no cover).
 

Jon_101

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Mar 5, 2019
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Would it be reasonable to assume these are cheap off-brand supplies? Regardless, My opinion is one or more of the following: supply fan bearings bad or fan is low quality (blade design and/or bearings), no supply fan control (the fan is always full on), rigid mount to base, base is acting as a sound board, and/or the enclosure itself is amplifying the sound (an acoustic resonance as it were).

If these are yours and you are trying to fix the problem I would first replace the fans. Find one with the same mounting size/pattern of course but a fan with a low db noise rating. Also keep an eye on the cfm (air volume throughput: Cubic Feet Per Minute) that is try not to sacrifice cfm to gain lesser noise. Least favorable choice is an acoustic sealed enclosure which will be a pain to deal with.
If I have to replace the fan, should I chose bearing or sleeve type?
 

TerryK

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West Central Ohio
Low noise fans will typically have sleeved bearings. Roller bearings create more mechanical noise from rotation of the balls and races. Sleeved bearings will be a type of oil impregnated brass or bronze (and in some light duty situations, delron or similar). Kept clean and lubricated roller bearings being steel on steel will have a longer lifetime.

To answer your question, I would not pay much attention to either but rather look at the cfm and db noise ratings. Although not previously mentioned, perhaps also MTTF (Mean Time To Failure). Essentially, let the manufacturer choose a combination that gives the purchaser what is wanted.
 

David_AVD

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I avoid sleeve bearing fans as I've found they don't hold up very well over time, especially with heat.

The ceramic or "mag-lev" bearing type are what I use.

The blade geometry can play a big part in the noise. Make sure to check the dB rating.

You don't always need the highest CFM (air flow) rating as long as it moves enough to exchange with cooler air.
 

lithgowlights

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Like David I am now moving towards the maglev fans for inside the PSU's, and use the cheap sleeve ones I still have for case ventilation as they are easier to swap out when they fail.
 

Jon_101

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Like David I am now moving towards the maglev fans for inside the PSU's, and use the cheap sleeve ones I still have for case ventilation as they are easier to swap out when they fail.
Do you buy them from ebay?
 

algerdes

Al Gerdes
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Exhaust at top left, at time of recording the lid wasn't on ( no cover).
Sorry, I wasn't clear. Where are the fans on each of the power supplies (not the one in the box)? I see the grill work just above power connection screws (probably air intake) and the power supply body appears to be solid. I have several power supplies similar within which the PS fan is on the bottom, pulling the air through and then shoving the air down.
 
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