Lightproof/passive intake cab design - please critique

[marx2k]

I wasn't sure how to phrase the topic correctly. This is an idea for a design for the bottom (or top if you wish) of a cab that functions to block light completely while allowing a large amount of air to flow through. Please tell me what you think.

Let's say we're looking at the bottom of the cab, from underneath.

Let's say that the planks used to construct the frame of this bottom are 4" high, raising the bottom of our cab 4" off the ground.

This picture shows a 3'x3' cab. Along the middle of the floor, we have a one plank from one end to the other measuring 34". It bisects both sides of the cab. Each section of the cab has a light trap that allows air to pass through. The gap that allows the air to pass through is 6"x4" on each side. The air comes in through the back of the cab via a gap in the frame that is 20" or more in width, spanning both sides equally. The top of the rear gap in the frame stops at the floor of the cab

The air (red line) flows through to the front of the frame and comes up through a hard metallic mesh that is built into the floor of the cab. The plants can also sit on this mesh without making a real dent in the flow restriction of this design. (or you could just drill a large number of holes in the floor of the cab).

Basically, this makes a 4" tall compartment for the bottom of the cab that works as a light trap and passive airflow intake that can take a LOT of air flow. You can maximize your airflow by making the two 10.5" planks that act as a ligh trap shorter.

This can sit directly on the floor or if you like, you can put another 3'x3' board underneath this (this would be a must if you use this design as the TOP of your cab, of course) Not very hard to build and zero maintenance.

What do you folks think about this?

 

[badgr]

Looks good. I made one similar. Just make sure the air can flow easily.

 

[marx2k]

What did you use at your intake point? (Where I am showing metal grating) Did you just drill a bunch of holes or what did you do? Also, how did your measurements differ and if you had to do it again, what would you do?

 

[green_grow]

i like it ... a lot, but if i understand the design correctly, without the 3' x 3' board to tie it all together, this assembly would be quite floppy. no ? that aside, i think i may want to use this as i do have light leaks at intake that i would like to eliminate.

 

[marx2k]

i like it ... a lot, but if i understand the design correctly, without the 3' x 3' board to tie it all together, this assembly would be quite floppy. no ? that aside, i think i may want to use this as i do have light leaks at intake that i would like to eliminate.

This framework sits directly under the 3'x3' board which is the floor of the cab. It is screwed/nailed directly into it. Also, for added stability you can attach another 3'x3' board underneath this construction, compartmentalizing the entire intake/lightproofing system.

The other option is that the sides of the cab extend down to the floor, which can make the sides of this construction instead of using seperate 4"x1" boards (the 34" boards in the picture). Same goes for the back.

You can also remove the middle 34" plank that bisects the two sides of the construction and just have one 21.5-22" board going across (which, in the picture, is bisected by that long 34" plank in the center) Though Im not sure if that would make the design less stable if you're using it as a bottom.

 

[Guest]

so ....your going to have 10" of grow room?

thats what am getting from the pic...

 

[marx2k]

Nope. You're looking at the bottom (the footprint) of the cab. This isn't the height view. This is the underside.

 

[Guest]

duh I understand now,but dont you want the output air at the top of the box

 

[marx2k]

duh I understand now,but dont you want the output air at the top of the box

The output air in this case would be at the top of the box. In my case, I plan on building a cooltube setup with a carbon scrubber inside the box and ducting flowing air out the top or the top/back of the box.

The thing is, this setup can also be done at the top of the box and you can still have your output at the top/back of the box. Here's why. If your carbon scrubber is sitting on the floor of your box, the air is being pulled from the top, to the bottom, into the carbon scrubber, up the ducting into the cooltube/reflector setup, into ducting and up through the back of the box. So the air actually makes a complete tour of the box. Which is actually a pretty good way of doing it.

Now, if you have this system on the bottom of your box and the air is coming in from the bottom AND your scrubber is on the bottom of the box, what's basically going to happen is that the passive intake will feed air from the bottom and the air will flow directly into the carbon scrubber without making a complete round of your box. (This works the same for any passive intake system).

So now, the question is.. with the passive air in the bottom of your cab, do you mount the carbon scrubber cylinder horizontally in the top back/front corner of your cab or do you just say fuckit and not care and leave it sittin on the bottom of the cab?

Remember, mounting in the top back or top front corner horizontally will free up a lot of floor space for your babies. I'm considering doing it this way, but the ducting will also be an issue. I'm trying to get as few bends in my ducting as possible since (from what I understand, correct me if I'm wrong), the more bends in your ducting, the more air resistance there is and the more noise you're going to get on output.

Of course, I'm also planning on muffling the output but still.

 

[Guest]

it is possible to get ducting made, to exactly what you want, like one inch thick and 14" wide...or whatever would save you the most room.

the duct could be made from foam board also .. it would be up to you ,and how you like to grow .

 

[hogwild]

you know i tried doing something like this in the past and it was a headache. I found it easier to get 3 inch diameter or larger ABS and make an intake that has at least 3 bends in it, or if you only want one bend, just make sure theres some distance between the light hitting the intake tube and where the tube is on the outside on the box. It works very well and keeps the light out.

 

[marx2k]

it is possible to get ducting made, to exactly what you want, like one inch thick and 14" wide...or whatever would save you the most room.

the duct could be made from foam board also .. it would be up to you ,and how you like to grow .

Well, the ducting I'm talking about has to go from the carbon scrubber, through the cooltube, through the fan and out the exhaust. It's all 6" diameter round ducting except the cooltube which has a 4" diameter (ducting reducers will be used).

So really, there's not much choice as far as this goes.

you know i tried doing something like this in the past and it was a headache. I found it easier to get 3 inch diameter or larger ABS and make an intake that has at least 3 bends in it, or if you only want one bend, just make sure theres some distance between the light hitting the intake tube and where the tube is on the outside on the box. It works very well and keeps the light out.

Darkroom louvres (spelling) would work just as well without all the protruding and taking up space of the ABS

I'm wondering what aspect of this was a headache for you? I mean really, it's just nailing wooden boards into a plywood base. So before I go ahead and build this, sort of base, which part of it was a problem for you?