New Grower Which makes more noise, four or six inch inline fan?

[poppycock]

Im in the process of building a stealth cab. I will be using led so heat removal will not be an issue while noise and smell will.
I plan on using a filter, muffler, speed controller and i do not mind lowering the speed to below 50% even though i will be replacing the fan more often.
I was wondering if a four inch will be quiet enough or should i just use a 6 inch at a very slow speed?
P.S. Im trying to have it quiet enough that 20 inch floor stand type fan could mask the noise.

 

[The Squid]

Hello. You'll still need air exchange no matter what light. And LEDs do put off heat. Just so you know.

My guess would be that the 6 inch would be louder, but perhaps if you have a bigger fan set low then that would be better. Can't say for sure. Hopefully someone else will.come along with more suggestions.
Take care.

 

[Gilbert Shelton]

FWIW, I run one of these: http://www.amazon.com/Panasonic-FV-...F8&qid=1357160118&sr=8-3&keywords=whisperline .

Moves enough air to keep a 400w HPS under 80F in a 4'x2'x6' tent. It's not cheap, and it's louder than a quiet oscillating fan, but it's quieter than a loud oscillating fan - if that makes any sense. Probably overkill for what you're doing, but maybe worth considering.

 

[tryptophan]

If you are talking noise levels caused by the air movement itself and not the noise of the operating motor, my suggestion would be to use the larger fan, the key question is which one? well you are going to have to do some research for that one, the things you want to look for are going to be the fans with lower normal operating RPMs and lower CFM ratings, this is because these two things will determine the amount of disturbance the fan is causing to the air being moved. Less disturbance=Less noise. The smaller 4in fan blades when chosen the same way will actually be quieter but will probably not move enough air. If you are talking noise of the motor itself you are going to have to check out the manufacturers’ dB ratings. (Decibel: a logarithmic unit of measurement in acoustics and electronics) the lower the rating the quieter it will be.:thumbs:

 

[poppycock]

I was thinking i.would have a 2x2x3 foot area, about 24 cubic feet. sub 100cfm would be plenty with leds. I may reuse my 250hps with cooltube Which should keep cool with 100cfm if im not mistaken. i worried about mainly the noise for the unit since i will use a muffler to reduce noise exiting the cab. I just need the noise to be quiet enough to where a fan (regular revolving multi speed fan outside the cab) can mask the noise.

 

[phoenix rising]

The sunleaves windtunnel 4" is the quietest i've found so far.Plastic housing to reduce vibration and pumps out 200cfm.They do make a 6" version,i bought mine from greners.com

 

[poppycock]

Thanks guys ill look into the whisper line. I think a four inch at half speed should work.

 

[poppycock]

Does anyone know how to rep+

 

[The Squid]

Click on the star down on the bottom left of someones post. You'll see what to do.

 

[cres]

4"...