[ricknroll]

Hey y'all,

I'd like to replace the noisy fan in the power supply for my Soundcraft Ghost but don't know what the requirements are for the fan.  I know it's a 12V fan and it's an 80mm size, which is a common computer fan size.  I recently bought a replacement fan for my HD24 and it uses the same size fan as the Ghost PS, but I don't know if all 12V fans of the same dimensions are really interchangable.  Are there other factors I need to be concerned with besides the physical size and the voltage?  For example, the new Silenx fan I just got for the HD24 is rated at less than one watt whereas the fan in the Ghost PS is 2.4 watts.  Do I need to look for a fan with a particular RPM, or will any 12V 80mm fan work?

Thanks,

Rick Hedges

[johnR]

The air flow specs are the important thing. If you can find one that blows the same amount of air as the original one but is quieter, use that.

[ricknroll]

John,

Thanks - I've noticed a CFM rating on some fans that apparently stands for "cubic feet per minute."  If I can figure out what the CFM rating is on the stock fan, is that sufficient for determining a suitable replacement, given the same size and voltage?

Rick

[johnR]

ricknroll wrote on Wed, 08 August 2007 22:38

John, Thanks - I've noticed a CFM rating on some fans that apparently stands for "cubic feet per minute."  If I can figure out what the CFM rating is on the stock fan, is that sufficient for determining a suitable replacement, given the same size and voltage? Rick

Yes.

Sometimes they are rated in litres/second. 1 cfm = 0.47 l/s.

[paully]

ricknroll wrote on Wed, 08 August 2007 13:24

Are there other factors I need to be concerned with besides the physical size and the voltage?

>>>>>>>>>>>>>>>>>
One more thing.. AC or DC. I didn't see it mentioned.

best, Paul

[ricknroll]

Paul,

The fan is DC.  I don't think I've seen any fans like this commonly used with computer power supplies that are AC, although it's not like I spend a lot time looking for these either.  

I was able to locate the specs online for the stock fan and it's rated at 40 CFU.  So far I have not been able to find a quiet fan that matches this output.  I bought a 32 CFU/14dBA fan to replace the fan in my Alesis HD24, but the Ghost power supply evidently requires more air movement.  I've looked at SilenX, Acousti, and other fans (also searched at digikey and mouser), but haven't found any rated at 40 CFU that are below the stock fan's noise spec (33dBA).  Does anyone know of any specific fans that would be a good replacement?

Thanks,

Rick

[garret]

If I'm reading this correctly, the Silenx 80mm fan w/ thermistor was measured as delivering 42cfm when fed 12v.  It's rated at 30cfm, but they measured it higher.

http://www.silentpcreview.com/article689-page4.html#silenx

If you are concerned with noise, installing a fan with a thermistor would be a good idea... there's a chance it will drop the fan speed to match the actual heat load, and the noise will drop significantly.

[ricknroll]

Garret,

Thanks, that's great info to have - I didn't know about the thermistor fans.  Like you said, I guess the noise savings comes when the fan doesn't have to run at full speed, which hopefully it won't have to do the majority of the time.  The Silenx running at 40 CFU has the same noise rating as the stock Sunon fan but as far as I know the Sunon runs at full speed all the time.  I'll probably order one of these and see where it gets me.

Rick

[Andy Peters]

ricknroll wrote on Thu, 09 August 2007 10:17

I was able to locate the specs online for the stock fan and it's rated at 40 CFU.  So far I have not been able to find a quiet fan that matches this output.  I bought a 32 CFU/14dBA fan to replace the fan in my Alesis HD24, but the Ghost power supply evidently requires more air movement.  I've looked at SilenX, Acousti, and other fans (also searched at digikey and mouser), but haven't found any rated at 40 CFU that are below the stock fan's noise spec (33dBA).

If you want a quieter fan that moves the same amount of air, it has to have a bigger diameter.

-a