I was wondering if anyone knows of a good 120V AC mains fan replacement for our old rigs? One of my S100 computers sounds like a jet engine. These old fans blow a lot of air but they're so loud. Anyone know of a good 120mm X 38mm fan that's quieter? I seen this one on Amazon but it says it's "Low Speed" so not certain it'd be the appropriate replacement.
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Good quiet 120VAC Case Fan Replacement
- Thread starter nullvalue
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I found the high speed version of this fan but its rated at 47dB, not much quieter than the one I have in there. There's this one which claims to be 41dB @ 2800 RPM... Am I better off going DC or at this high RPM rating will that not really matter in loudness?
Chuck(G)
25k Member
To reduce fan noise in a couple of old computers, I set the jumpers on the fan (multi-voltage) to 220V and ran it at 120V. Still pushes enough air, but much much quieter. My experience is that non-"muffin" fans are better for this; the problem with AC muffin fans is that the motor is at the center of the thing and takes up quite a bit of area, meaning that the fan has to run faster for a given air volume.
You may want to consider an appliance fan or just use a DC fan. One of those things--DC fans are far more efficient than AC ones.
You may want to consider an appliance fan or just use a DC fan. One of those things--DC fans are far more efficient than AC ones.
Hugo Holden
Veteran Member
The 120V FAN in the SOL-20 is reasonable for low noise an has good air flow. It is a solid item with a cast alloy body and the exact part is still available on Ebay. It makes a modern plastic fan look like junk. I bought one a little while back as a spare for my SOL. I would have to hunt out the part number.
Plasma
Veteran Member
- Joined
- Nov 7, 2005
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McMaster-Carr has some nice fans. Not cheap but they are made in the USA.
Hugo Holden
Veteran Member
I could tell some interesting Fan stories.
One is a fan from a vintage Avionics VDU. The whole thing ran off 400Hz airplane power. See attached.
The thing is, designers forget, the higher the drive frequency, the more likely it is, that frequency is in the "audio spectrum".
The 400Hz fan in the attached photo, made an excellent 400Hz speaker.And you would swear you were in a high powered plane.
The designers of modern air con units, thought they were smart; "Hey lets make a pwm controller for a DC fan motor for an air con unit". So efficient it will be, compared to the typical AC motor and phase shift capacitor running off 50 or 60 Hz that lasted 50 years in the old air con units.
No, we will make an electronic controller, with a power IC and a few thousand semiconductor junctions.
But guess what, the fan blade behaves like a giant speaker, you will get very annoying 700 HZ to 1500 HZ "tones" out of your pwm controlled air con fan that will drive you & your neighbors up the wall. And when it fails, you won't be looking around for a simple 20uF motor run capacitor, but a highly complex pwm controller IC.
One is a fan from a vintage Avionics VDU. The whole thing ran off 400Hz airplane power. See attached.
The thing is, designers forget, the higher the drive frequency, the more likely it is, that frequency is in the "audio spectrum".
The 400Hz fan in the attached photo, made an excellent 400Hz speaker.And you would swear you were in a high powered plane.
The designers of modern air con units, thought they were smart; "Hey lets make a pwm controller for a DC fan motor for an air con unit". So efficient it will be, compared to the typical AC motor and phase shift capacitor running off 50 or 60 Hz that lasted 50 years in the old air con units.
No, we will make an electronic controller, with a power IC and a few thousand semiconductor junctions.
But guess what, the fan blade behaves like a giant speaker, you will get very annoying 700 HZ to 1500 HZ "tones" out of your pwm controlled air con fan that will drive you & your neighbors up the wall. And when it fails, you won't be looking around for a simple 20uF motor run capacitor, but a highly complex pwm controller IC.
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Thank you, looks like they have an 80CFM model @ 34dB - not bad, pretty pricey but I may give that one a try..
hornbetw
Experienced Member
An avionics company I worked for built a "Bingo Fuel" display for the F18. Bingo Fuel is the minimum fuel a Naval Aircraft needs to return to the carrrier. When we fired up the display in the lab, it sounded like a small jet engine. They needed high airflow because the display sits right next to the HUD, fully exposed to the Sun coming in the canopy. The pilot couldn't hear the fan over the jet engines.