Loud fan and negative pressure solutions needed

Heres my problem. Running an 8" ceiling mounted intake fan for a 150' sq. ft. room. WAY too noisy and can hardly open the entry door. Thinking of downsizing to a 6" fan or? Throw some ideas at me, im all ears. Thanks

Mount it with bungee cords! Solves the noise problem instantly Basically just let it hang there so it has nothing to reverb against. BTW Cubic feet matter way more than square feet, at least for CFM sake. Negative air pressure will be accomplished as long as your exhaust is stronger than your intake. Hope this helps!

Dreadheadgrow said:

Mount it with bungee cords! Solves the noise problem instantly Basically just let it hang there so it has nothing to reverb against. BTW Cubic feet matter way more than square feet, at least for CFM sake. Negative air pressure will be accomplished as long as your exhaust is stronger than your intake. Hope this helps!

Click to expand...

100% agree

a $20 speed controller and you can slow it down a little, which will also help with noise

If you can barely open the door have you considered changing your exhaust and intake to make it a negative pressure instead of a positive? (seems like your intake is larger, when the exhaust is larger it allows an neg. pressure) Obviously this is not always possible, but what if you just put your intake fan on your exhaust and your exhaust fan on your intake? Does that make sense? You could also (in theory) entirely reverse the flow in the room, intake threw your current exhaust and exhaust threw your current intake? Assuming that it is an inline fan i would agree with mounting it on bungees for the noise, or if possible kick it entirely out of the room. Using insulated ducting helps to isolate noise also.
I just reread the title, do you have an inswing (into) or outswing door on your room? I assumed inswing, if it is inswing you have positive pressure not negative, outswing then negative pressure is the issue and most of my post is stupid, hadn't smoked yet and now i have, thats funny, im smarter high.

Thanks Guys, both intake and exhaust are 8" fans. I will check out the bungee idea.

Excuse the sideways pics, dont know why it happens, mentally rotate all pics downwards to the left 90 degrees for accurate images. Left pic is vertically mounted intake with in main room with no fan which runs thru melonheads, middle pic is filter which is mounted horizontally from ceiling and has "8 exhaust fan, right pic is veg room exhaust fan with 8" exhaust fan which makes the run from the far left intake pic, veg room also has a 8" damper for fresh air.

Anyone know if Ostberg fans are dimmable? Trying calling them 3 times and on hold for days.......................

Mounting the fan with bunges will ONLY help with vibrations not with how load the fan is.....have you thought of trying a silencer? I use an 8"inline fan in an Aprtment grow i use a 4foot silencer on the exhaust end of the fan.... and i attached a carbon filter to the intake side of the fan this way i have silenced the fan from both sides one side using a silencer and one side using a carbon filter....... I also use a speed fan controller like the one guy said.....this allow me to run it at lower RPM making is even more stealthy if i need.......

wrap the fan in duct insulation!!! or any insulation.

put the fan in a cooler {igloo}

use insulated ducting

use a carbon filter or duct muffler

if you can hardly open the room door you have way too much pressure.

if its blowing out you need larger intake vents. 3 x 8" holes for passive intake.

if you use a fan speed controller, USE THE RIGHT ONE. different fans have different motors which need tobe controlled the right way...

Get a "VariAC" from MPJA.COM the highest amp model you can afford. as you reduce voltage amp draw increases from what is on teh label of your fan.

variac slows a fan by reducing voltage but NOT clipping HZ {frequency}

frequency is very important in an electric motor as it affects teh motors timing.

This is why ceiling fans on dimmers hum. and burn out prematurely.

Situation under control, thanks to all you who posted!