Fan Silencers Worth It? And Fan Q?

[Sixty-Eight]

hey guys

 

ive never really had to worry about fan noise before but this past grow the fan i was using is a 100mm centrifugal fan with standard ducting and placed on the floor the thing i really dont like about the fan is its pitchy in noise and i get a real annoying woosh/hum all up the hallway to the front door!

 

im going to invest in a cheap little 150mm axle inline fan its specifically designed to run carbon filters and aircooled hoods this grow, it was quiet running on the floor at the shop but once put onto a carbon filter it was louder so with ducting it should quieten some

 

now im wondering about fan silencers are anyone running these? is it best to use two one on each end of the fan or is one sufficent? ive never heard one being used or tested so i donno

 

ive found a new set up i like its a 1.2x1.2m tent, 150mm aircooled hood, just waiting to purchase it

 

do u think i could run one of these (i wont be buying anything i link from that link) http://www.ebay.com.au/itm/231478283946?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT thru the tent than filter than the aircooled hood and out the tent

 

or do u think i should bite the bullet and pay big bucks for one of these with a inbuilt silencer http://www.ebay.com.au/itm/261783936587?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

i think im set on what i want just need reassurance

 

just thinking of some theiving bastard ripping off a $350 fan while im not home i would be shattered

[Sir PsychoHashy]

You can't get completely silent airflow, but there are things you can do to minimise the noise.

 

I wouldn't bother with that 1st fan, just doesn't look to be of a good enough quality, and if you are looking to reduce noise it's worth spending the extra on quality gear.

 

The whisper silencer fan?  I thought about it but couldn't warrant the cost, they are meant to be good though.

 

Best advice I can give is as follows:

 

• Go a larger fan with a fan speed controller designed to match, or built in.  200mm would be better than 150mm as you can run it at a much lower speed.
• Put the fan inside some sort of sound insulation to reduce the actual fan noise.
• Use acoustic or insulated ducting.
• Certainly no harm in using a fan silencer after the fan, but I'm not sure how much difference they make, especially if you have a couple of metres of duct after it.
• Carbon filter on the intake helps silence fan noise from that end.
• Find some way to diffuse the air as it comes out the outlet.

 

You'll still get some airflow noise, and maybe a little hum from the fan itself, but should be able to get it so that it's only noticable from very close by, and not overly obvious.

 

I ended up going with a 200mm Hyper fan and separate silencer and am very happy with the outcome.  I also got a 150mm Hyper Fan for the small veg tent, and found that despite having to move a lot less air it is actually making more noise overall, but it's still ok stealth wise for a 120*60*90 tent running 250w through a cooltube, with insulated duct and silencer.  If I had to run it any harder though, I would not be happy with it.  Hope that helps.

[Ozzy420]

IMO the fan silencers are a waste of $$.

 

I have one that i did use, dident notice any diff once i hooked it up wont be using it again.

 

I will be using insulated ducting my self in my next setup...

[cap'n yNg]

Aye agreed.

Silencers only work if it's the last item in the chain. IE, the air exits from the slilencer, but you will still get air noise inside the ducting, hood/cooltube, carbon filter. Insulated ducting is the way to go, when I installed some it reduced the air noise in the whole system by +50%!!

It is impossible to completely dampen the noise created by the air movement, so insulating it is the best way. Like you did wrapping ya fan in a doona

Another thing to consider is the vibration fans create. This 'rumble' will travel though the floor, walls etc, so mount them on top of something like rubber, foam even a towel, alternatively hang the fan using rubber straps.

Edited February 20, 2015 by cap'n yNg

[Sixty-Eight]

glad i asked i would have sunk a couple hundred in the silencers, do u think i could run a 6" fan externally from the tent

 

say run a carbon filter at the top of the tent than ducting to outside the tent connected to the fan on the floor than run the ducting back up into the tent than thru the aircooled shade than out the tent? sounds complicated

 

but having the fan on the floor outside of the tent i could chuck another 2-3 dooners over the fan to keep it quiet

 

this idea might be the go? this way i can run 1 fan and it'll be a 6" centrifugal

 

anyone got a good branded centrifugal fan they'd recommend? i bought a 100mm white version from ebay and found out it was leaking thru the two joints

 

new fan: less wattage = quieter centrifgal fan? i see some 6" fans are rated at around 60watts some other 120watts

[cap'n yNg]

Hey 68.

Yeah that configuration will work fine. I did mine a similar way in my wardrobe grow space. I had the fan on a shelf above the grow space and just ran the ducting out to the fan and back in again to the outlet. And, of course, covered the fan with a doona to reduce noise.

I also constructed a tight fitting jacket for the fan from a foam gym mat that worked a treat, still use it today

 

My current 6" fan is on its last legs, the bearings are going, so I've been looking about for a new one and like the looks and info of the Hyper fans. The 150mm, which I'm looking at is only$250 with fan speed controller. The latest dc motor, low db's, energy use and a snazzy blue colour . And just under 200 if you don't want the speed control.

Have surf man. https://www.sunlightsupply.com/shop/bycategory/fans-ventilation-ducting/hyper-fan

All the best!

Edited February 21, 2015 by cap'n yNg

[Sixty-Eight]

Hey 68.

Yeah that configuration will work fine. I did mine a similar way in my wardrobe grow space. I had the fan on a shelf above the grow space and just ran the ducting out to the fan and back in again to the outlet. And, of course, covered the fan with a doona to reduce noise.

I also constructed a tight fitting jacket for the fan from a foam gym mat that worked a treat, still use it today

 

My current 6" fan is on its last legs, the bearings are going, so I've been looking about for a new one and like the looks and info of the Hyper fans. The 150mm, which I'm looking at is only$250 with fan speed controller. The latest dc motor, low db's, energy use and a snazzy blue colour . And just under 200 if you don't want the speed control.

Have surf man. https://www.sunlightsupply.com/shop/bycategory/fans-ventilation-ducting/hyper-fan

All the best!

 

i may run with that idea thanks man, have u heard how loud the hyper fans are? ive heard one run from low to high a couple of times now and they are so bloody loud its louder than a 6" centrifugal fan but they move a shit load of air

[Sixty-Eight]

forgot to ask are u guys running insulated ducting or acoustic ducting?

[Sir PsychoHashy]

I'd have to agree that the Hyper Fans get a good jet engine whiney noise about them when you crank the speed up on them, and that the whine aspect at least is worse on the 150 than the 200.  By going a bigger fan than necessary you can use the speed controller to dial it down and dramatically reduce the noise.  My 200 running through insulated ducting with some insulation around the fan itself pushes enough air for my big tent at a lowish speed setting, there is air flow noise at the outlet which cannot be prevented, but overall the noise level is low enough for my high stealth requirements of a garden shed within a metre of 2 neighbours fences.  If I was using the 150 in that tent, the noise would probably be too much, but it's still quieter overall than the 150mm  centri I used to use.

[Sixty-Eight]

i may need to upgrade my carbon filter its only a 100x300mm type so ill need a 150mm filter and fan but now we are talking big bux $$$ a 150mm centrifugal is the cheapest option but probably the loudest

 

my 100mm fan is rated at 48db the same model but in 150mm is rated at 50db do u think there would be that much difference in sound going from 100-150mm?