120x25mm OR 120x38mm which is better?

[bupkus]

I don't know if a speed control works equally well with either of these.

Both are YS-Tech fans and both are supposed to operate at 45dB(A).

The 25 has 7 sweeping blades, whereas
the 38 has 5 blades.

 

[cheapgoose]

i would go with the quieter one, but make sure that if you get the 38mm, make sure it doesn't run into anything. I used to have a 120 x 38 as a exhaust, but when I changed heatsink, the fan was in the way, just make sure there is plenty of room.

 

[Zepper]

All else being equal, the 38mm will move lots more air. Check the CFM rating. As -goose said, take clearances into consideration.
.bh.

 

[snowwie]

I have the 120x38mm, and it is a really good fan

it is kinda loud though, and I lower the voltage, though at some lower voltages a drone comes off from the motor.

I play with the voltage though and I can get rid of the drone

But it moves a LOT of air, more than any 25mm thick fan I know

 

[bupkus]

I was thinking of modding my case with a 120mm blow-hole. Also, I'm thinking of a 5.25" front panel with fan speed controls.
Quiet is my biggest concern. That 's why I would do the mod in the first place. Perhaps the 25 will better fill the bill.
I've got time to make that decision.
But according to YS-Tech's web site, even though they deliver with the same 45dB noise level, the 38 pushs alot more air.
How can they both have the same noise level?

Maybe a big panaflo is in my future?

 

[hardwareFan]

Don't know if this makes a difference, but I have the 25mm one, and its loud as hell.

 

[bupkus]

Is it just the YS fan that's bad?

Did you try to slow the fan down?

Think the panaflo could please?

Is this just a dumb idea?

 

[Zepper]

Many fans quiet down when you slow them down. Some have resonance points and can come up with some strange noises at various rpm points. Most of these small fans are designed to a fixed speed - no telling what you'll get when you change it.
. The angle of the fan blade at a given rpm has the most effect on CFM - open blade, more air - closed blade - no air. Ask any prop plane pilot. The 38mm depth allows for a much more open blade. Fewer blades allows ambient air to fill in better behind each scoop.
. Look up the fan's specs on the mfr's web site or in a good parts catalog like Newark or DigiKey. It will tell you the allowable voltage range. Most 12V fans will work OK from 7V up.
.bh.

 

[snik]

Originally posted by: bupkus
Is it just the YS fan that's bad?

Did you try to slow the fan down?

Think the panaflo could please?

Is this just a dumb idea?

Not a bad idea at all. But be prepared for either YS-Tech fan, they're loud AS HELL. I know I'm not knocking YS-Tech (I have 2 120s and 1 80) they're just loud. But hey, they move insane amount of air. If you want a quiet case, building/buying a fan speed controller is a must. That way you can control the speed/CFMs whenever you want. I have this controller for my 2 YS Tech 120x25s. Works very nicely and they're quiet. Svc has the controller starting from $14.99.

If you dont want a fan speed controller and want quiet, skip the YS-Tech ones and get low rpm 120mm fans. And I do mean LOW (1400-1500)

Whatever you decide to do, 120mm fans are still much better than 80mm ones. Quiter and push much more air.

 

[farmercal]

What about this Fan it pushes 84CFM at only 32 dB(A).

 

[Zepper]

farmercal et al.,
. That fan is something... But it has a relatively short TTF. Wonder if one could press the fan guts out and press in the guts from another fan when it quits...
.bh.

 

[snik]

Originally posted by: farmercal
What about this Fan it pushes 84CFM at only 32 dB(A).

I think the info is a little off. I've owned one of these and they're real nice, but it's sure is louder than 32 dbA. I have 33 dbA 80mm fans and the chrome 120mm is a lot louder.

 

[cheapgoose]

Originally posted by: snik

Originally posted by: farmercal
What about this Fan it pushes 84CFM at only 32 dB(A).

I think the info is a little off. I've owned one of these and they're real nice, but it's sure is louder than 32 dbA. I have 33 dbA 80mm fans and the chrome 120mm is a lot louder.

what he said. have 2 running on 7volts.

 

[amcdonald]

I had one of the aluminum fans, and they are louder than rated, but nowhere near 45db (thats REALLY loud).
Also i had it undervolted to barely on (i'm mainly concerned with silence) and while working inside my case it nicked my hand and broke a fan blade.
$18 gone because of cheapo plastic. I got a stealth to replace it and its a lot smoother in its audible noise. undervolted its almost silent.