Changed from Stealth cab to my closet and need intake help/advice

[LoverofLife]

Ok so the area that I was wanting to put my cabinet is scratched.. Too low of a ceiling and not a good exhaust area (I'm a renter).

Here's my part list and grow: 600w Digi Lumatek MH/HPS. 440 CFM exhaust fan with a ridiculously huge scrubber (carbon filter). Going for 2 plants only in flower with a perpetual grow once everything is going well. Using a 18g bin with DWC with a top feed as well. Will start with 4 seedlings (blue dream) and pick the best 2, once they get well enough to transplant they will have their own 18g bin for extra space.

Now here is my hard questions. I'm using the pictured closet but the doors to it don't allow much air, if any, to get in when closed. I was going to use a passive air intake with the 440 cfm fan and I had 5 computer fans I could pick from. But that changed when going into this closet and I can't cut a hole in the door for fans...
-Can I tap into the (other picture) AC line on the other side of the wall without causing HVAC issues with my central air? I'm thinking this wouldn't work considering I'm sucking all the air from the AC duct versus it just blowing the air in the closet like it would out of your vents normally. Also the AC doesn't run all the time so when it shuts off I'm back to not having an intake at all other than the small crack at the bottom of the door.

What do I do here to have plenty of fresh air without making anything obvious? Please help ladies and gents.

FYI- A fish tank will be next to the closet just to have noise...

 

[Antics]

Welcome to the club!

I have virtually the exact grow area, similar double doors, although your room looks bigger than mine.

But growing with a 600w HPS in a closet without the ability to vent properly is asking for trouble. Ideally, you'd be running 6" minimum ducting, using a cool tube hood, and would be venting directly out of the room.

Your best option in my opinion? unless you can cut drywall, and completely repair it, the easiest alternative would be to buy a cheap set of doors, store those doors somewhere, cut your new doors for intake/exhaust, and you're all set.

Tapping into the AC line is too inconsistent, since it relies on temp at the thermostat, and not the temp in your closet.

 

[LoverofLife]

I'm going to exhaust through the ceiling in the closet with the 440cfm fan and 6" ducting. I'm totally skipping tying into the AC as that sounds like trouble.

Buying 2 cheap doors is actually a good idea except I don't have any storage area for the current ones... I'm thinking of cutting 2x 4" holes on the top of the closet that faces towards the room the closet is in. Now I'll run a 120mm computer fan in each hole with 4" ducting dropping down to the floor area for the fresh air. To cover the holes that are now above the closet I figured I could put some decorative plates in front so that you can't tell there's 2 holes in the wall... What do you guys think? I'm trying to figure out my plans and I'm not good at drawing plans for this. Especially when I need 2 chambers with plenty of vents and a small area for all electrical stuff.

 

[Antics]

Another option would be to remove the moulding/trim at the top of the doors, and inside the closet if it exists, cut a small hole there that the moulding would cover, and you can use a squirrel cage fan in that sized area to vent. And when needed, you should be able to slide that exterior moulding back on using the original nail holes if that's a sheetrock wall.

The difficult part is removing the moulding if any nails are going into studs, there's a chance of damaging the wall. The best way is to lay a cloth on the wall, then lay a board on the wall to spread out the force of your prying tool, and to give you leverage as well, and just pry slowly and gently.