Need help silencing exhaust

[SmilinBob]

So, I built another cab. This time I mounted the fan directly to the back of the box.

My fan is a Delta AFB1212SHE, which I can't find on their site. 120x120x38 on a voltage regulator. Stats for this model are: [FONT=verdana, arial, helvetica][FONT=verdana, arial, helvetica]151.85 CFM @ 3700 RPM, 53.0 dBA, 12.60 watts, 1.65 amps, Maximum Air Pressure 14.50 mm H²O[/FONT][/FONT]

My problem is the air rushing out the back of the cab. Even running at 4.5 volts the amount of air this fan moves is insane.

Does anyone have any ideas for quieting my exhaust? I just want to check to see if anyone has any proven methods before I start tinkering around and using up resources.

This was the idea I came up with first, because it's so simple. But would it decrease how loud it is?

There is a home made carbon filter on the inside of the cab attached to the fan. The extension on the back would either be cardboard, or 6" pvc elbow.

Any advice, comments, ideas, anything anyone can give me is very appreciated.

 

[OrganicOzarks]

I have used "mufflers" in the past, but I actually thought that they make it louder. The noise is from the rushing of the air. Something to try is to get some carbon filter sheet from Walmart and cut a piece and tape it to your exhaust outlet. The downside of this is that it will slow down the air flow, and can possibly raise the temps in your cab. The only way to find out is to spend the $10 to do it. In my veg closet I am running a 425cfm inline, and i had used a 3' "muffler, and I think that it actually made it louder. I ended up just ripping the wall out, and connecting the exhaust to my return duct for my ac. It now keeps my veg at about 75. Which works well for me, and now there is absolutly no sound from the exhaust because it is buried in an insulated wall.

 

[SmilinBob]

Thanks for the idea. I think I have some carbon sheet left somewhere. I also have some air filter sheets that aren't carbon filter, which won't slow it down as much. I'll give that a try before I start building anything.

Keep the ideas coming guys.

 

[SmilinBob]

I stuck several sheets of carbon filter over the exhaust. So many that it stopped pushing air out, but I still here this sound.

Which makes me think the fans hum is part of the problem too. Any ideas how to make the fan quieter? I'm already using a voltage regulator.

If I can't come up with any ideas, I might just put a radio on top of the cab, and have it playing all the time.

 

[VerdantGreen]

if you isolate the fan from the cab so it is not touching (or put foam or something where it touches the cab), you can reduce the vibration noise.

also moving the fan back a bit into the cab with a short piece of ducting inbetween fan and vent could help.

 

[PuReKnOwLeDgE]

I hang all fans with rubber bungee straps, try that

 

[IwannatokeNbone]

my solution is simple, put a computer fan or fans for exhaust that are cheap n silent, add a vapourtec disk inside for odor and problem solved, no odor no sound. in a micro grow having elaborate exhaust isnt needed

 

[OrganicOzarks]

I hang all fans with rubber bungee straps, try that

I second that. I hang my inlines from bungees, and I wrap the shit out of them with insulation and gorilla tape. I can cut the sound down by about half that way.

 

[BC Chronic]

These are all awesome ideas...I use that sticky foam and mount my fan onto that..dampens pretty well all the noise...
If you have a dryer hose coming out the back( I do, just an example), wrap the hose in that vent insulation..the stuff that goes around vent pipes in houses to keep noise down (and also it keeps the heat directed to the scrubber!)..works very well for me..
hope you find the idea that works for you bro..

 

[big twinn]

I'm having the SAME problem! I also, have a Delta fan ....ha you beat me to posting this thread=P

If anyone has any solutions...we'd very much appreciate it! that rear vent angle idea you posted, i tested out, albeit very rudimentary, but i found it only decreased air flow and did nothing as far as sound. maybe if the vent is made large enough to put sound dampening isolation that would work? But this idea as far as exterior goes REALLY compromises the stealth factor of my cab....then again so does the noise. My carbon filter is helping, but still very noticeable.

 

[SmilinBob]

I tried putting foam between the fan and the cab. Problem still there.

I believe the problem is that the fan is so close to the exhaust hole. Putting some distance between the fan and the hole is the only way I see that will help me.

Problem is rerouting the exhaust will be a pain. Looks like I'll be heading to the store for an elbow and some ducting. Wish they made 5".

Thanks for the help guys

 

[IwannatokeNbone]

bump

 

[Ordinary Joe]

Is this the fan you have?

http://www.sidewindercomputers.com/deaf12suhisp.html

and it is still that noisy?

Give us an update on your progress...