Vent intake size - noise differences

[JoeRocket2]

I am venting a 5'x5'x6' room with a 170cfm vortex type fan sucking thru a carbon scrubber. My problem is that I am VERY restricted as to intake vent placement/size due to stealth issues.

Basically, my exhaust hole is a 6"x12" typical home fresh air return type duct vent & grate...which looks like it belongs where I placed it (keeping it stealth & wife happy).

I am trying to keep my intake hole/holes confined to an area that is covered on the outside of the room by a wood cabinet that is about 2" away from the wall I need to vent thru.....basically 2 walls with about a 2" gap in between for me to work with. So, I have about a 4" x 5' strip that could conceal my intake setup.

I am thinking about cutting 2-8 2" holes, then placing a wooden or stiff cardboard box, with some type of bends/channels to keep light from escaping and another opening into the room, over the holes in the wall. My hope is to keep noise to a minimum & light in with this box setup.

My other thought is to make a 2-3 inch by 2-3 foot slot in the wall, then come up with a light baffle of some sort.

I want to keep neg pressure in the room at all times for the scrubber, so I dont think I want too much intake, but I dont want a huge sucking sound either. I have run the scrubber & fan thru the exhaust setup, with the "intake" just sucking thru the cracks in the room & the noise wasn't too bad at all.....want to keep it that way if possible.

Any opinions as to which method might work out better?

Any better ideas? (there probably are)


Thanks in advance,

Joe

 

[FreezerBoy]

How's about another grate?

http://www.icmag.com/ic/showthread.php?t=74941&highlight=hidden+wall

If its too large, block some of it off or, downsize it with adapters/couplers.

 

[JoeRocket2]

Just got a couple of pictures.....

Before pic of entrance to room and closet 2" away from wall.





6x12" exhaust vent





Inside view - Left 4" or so covered by cabinet outside room. Would like to place intake in the area covered up by the cabinet as not to look like there are too many vents for one little room. And yes, it's a home hack-job on the duct!



External view of wall to room & cabinet outside. About a 2" wide x 4" deep gap that is out of view where I would like intake to be located.



Hope this gives a better idea of what I'm looking at.

Suggestions?

Joe

 

[HighonPottery]

you could make the intake hole inside of that cabinet/closet.

or without having to cut anymore holes on the exterior of your room, would be to put 90* bend on 6x12 exhaust vent you have and then pipe it down to the bottom of your chamber, then exhaust up through the ceiling in your grow room. this way it is light proofed and you get fresh air in to the bottom and old air out the top into the attic(?) above.

 

[JoeRocket2]

Highon, the ceiling and 3 walls are cement.....no chance for adding another hole unfortunately.




You know the saying, Measure twice - Cut once........I want to Plan twice & Cut once.

Anyone ever experiment with vent hole options??

 

[HighonPottery]

is it in a basement or something? what type of room is that grow area branching off of?

in the pic of the outside of your vent, the ceiling looks like acoustic panels. in the pic of the back side of your vent, it looks like the concrete ends and wood begins. where does this space lead to?

 

[Albert Hofmann]

My first question is do you need an intake vent? A 4" vortex doesn't pull alot of air, you may be able to get by with passive intake through the cracks in the room. If you have tested and the first suggestion won't be sufficient, then a simple 4" x 10" register vent mounted the tall way on the bottom of the door will do the trick. On the backside of the door (inside the grow room) build a light trap with a couple elbows.

 

[JoeRocket2]

It is a basement...a well room off of a corner to be exact. The concrete does end just before the basement ceiling joists begin, and I thought about that, but I checked and each "tube" for lack of a better word, in the ceiling between the joists only goes about 2' before it ends....boards block it off completely. I didn't think there was enough space there for an intake or exhaust....mainly dead end.