How is this fan?

[Postal Dude]

Papst 4650N
106CFM
50dB

They are 240v. i wanna use them to cool my condenser. How loud is 50dB?

Can i run them in series so they run slower?

Sean

[jason str]

50db is not something you want right next to you maybe you can pick up a fan controller (potentiometer) or resistor to ease the noise.

Maybe equal to a running A/C unit or street traffic to your ears.

[Postal Dude]

well they'll be bolted to an ac unit so meh! would a dimmer for lights work? got one here capable of 400w control. from nothin all the way up2 full power. jus had one hooked up to mains. more of a purr than anything. didn't feel like 106cfm though

[jason str]

The dimmer will work as long as it is rated at or above the amperage draw of the fan so not to overheat.

If you hooked the fan up for a dry run and its not too noisy dont worry about the dimmer the more heat you dissipate the better.

[Sparky]

No, dimmer for lights will NOT work.

Most AC motors are inductive motors (and those are I'm 99% sure), the speed is actually determined more by the AC frequency and the number of coils inside. I won't go into the nitty gritty details. Basically, if you use a dimmer and drop the voltage, in order for the motor to keep its speed as determined by the coil number and AC frequency, it takes more current. However, the coils were designed to only take x amount of current, so you go too far and you can overheat and burn out the coils, killing the motor. The only real way to properly adjust the speed of it is to adjust the frequency going to it, which isn't easy or cheap. A dimmer may seem to work at first, but the motor will gradually speed back up to almost full speed again.

Some AC motors you can use a dimmer switch because they are not induction motors.

[Shadowtester]

You can use either a resistor, potentiometer, or rheostat to control the fan both the potentiometer and rheostat would allow you to vary the speed as you wish the resistor would be a fixed speed adjustment.

[Postal Dude]

i'll have to agree with SparkyJoe on this matter as the fan pushes slightly more cfm and draws more current when hooked up to a 60hz circuit at 110v. So thanks for that nugget mate. Theyre quiet enough to deal with on the long term. Especially compared to what they are replacing.

Does this also mean they cannot be ran in series?

[Sparky]

I do not believe you can wire them in series, because of the problem I mentioned above. I'd have to check more to be sure on that.

[Asgard_thor]

106cfm is weak
my yate loons put out 88cfm @ less then 40db's so get two of those if you want high CFM fans

[Postal Dude]

Yes but are your yate loons 240v?

[Polizei]

106cfm is weak
my yate loons put out 88cfm @ less then 40db's so get two of those if you want high CFM fans

Those Yates don't output 88cfm... 75 if you're lucky. (http://www.xtremesystems.org/forums/showpost.php?p=2641543&postcount=3)