Closet Design Question - Air Intake

[wang]

Hey, so I'm in the preliminary stages of setting up a closet for a new grow. The space I'm looking at is 31.5"x33" and 8' tall, and it has a 6" exhaust duct that goes straight to the outside already built in.

I was thinking about just cutting some holes in the door for intake, but noticed that the door already has ventilation built in. We're looking at 2 panels, each 1'x3' in dimension, with wood slats stacked on top of each other.

Take a look at this to get an idea:

What I'm trying to figure out, are these going to be OK for intake? Would it be too much? Too little? Do I need to get a new door?

 

[Fattie]

The problem with that is that you wont be able to control where the air comes in, and if you are pulling from the top the air wont circulate before leaving the cab. You will probably have a closet full of stale air.

 

[wang]

Well, basically the cabinent they will be in will be level with the bottom of the slats. The reservoirs will be below the slats.

I'll probably end up blocking off 3/4 of the slats and cutting the other corner out and throwing an intake fan on there, thanks for the advice.

 

[Anti]

How are you going to keep light from leaking out (or in)?

 

[FreezerBoy]

How are you going to keep light from leaking out (or in)?

Damn fine point. I'd block the louvres and put vents at the bottom.

 

[wang]

Damn fine point. I'd block the louvres and put vents at the bottom.

I guess this is what I'll have to do. Was optimistic thinking I wouldn't have to cut any holes in this door.

Thanks guys

 

[Anti]

The idea that occurs to me (but will require a bit of building) would be to build a "box" that attaches to the backside of the door and uses the door (with louvers) as one of its 4 walls. Then you could make a ceiling for the "box" and use the bottom of the "box" as an inlet into the grow.

That way as your exhaust fan pulls air out of the closet, the louvers can pull fresh air into the box which will then travel down and be released into the cabinet from the ground up.

The box would serve a dual purpose of 1) blocking light coming in/out and 2) directing all that fresh air down to the bottom of the cab.

 

[wang]

Excellent idea!

The door is of the folding kind so it folds into itself so it will require a bit of thinking to be able to make a box that can fold up. When I get back home I'm going to examine the door closer and see how I can do this, or maybe just modify it so it swings open.

 

[wang]

Trying to get an idea on the boxes dimensions, with a 6" duct exhaust, you'd generally want two 6" intakes.

I may be showing my noobness here, but I'm going to assume that a rectangle of equal area to a 6" circle would be just as good? So 6" would be 28.26 sq inches, a 9x3.2 rectangle would be just about equal.

So if I use two of those 9x3.2 rectangle intakes on the bottom of the box, it would only take up about 3.2" of horizontal space instead of 6".

The size of the louvres is about 2'x'6 when you put the two sections together, and they're basically right next to each other

 

[Anti]

Rectangle or circle doesn't matter. The overall area is what matters and you seem to have a handle on that.

The difficult part of the equation would be figuring out just how much area there is between each slat in the louvers. As in, what's the total area of inlet via the louvers? If that total is 56.52 sq. inches then your plan will work out great. However if all the spaces between louvers don't add up to 2x28.26, then it won't matter what size you make the holes in the box and you'd still need to make intake holes in the door (or somewhere.)

If the louvers turned out to have an area equal to or greater than 56.52, making the rectangle (doesn't need to be two unless that makes construction easier) would still work great.

 

[wang]

So things are looking good! Figured out a way to unhinge the door from one side to make it swing open instead of fold, so the box idea should work perfect.

Took a look at the louvres, they are 1' wide, and the vertical opening is close to .25". There are 66 of them total, so that would be 198 sq inches total of intake, which should be more than enough and covers my ass for bad measurements as well. I'd say theres definitely enough intake there to make it work.