4x5x8 ventilation and humidity control

[Cheeba420]

Hello every this is my first post and I have a 4x5x8 closet grow room and I'm having trouble keeping the humidity down, the heat if fine and stays around 70-75 degrees but I have 2 damprids in the room and I don't think they're doing anything or helping much cause the humidity when I open the door and check its around 75% which I know is way to high, so I was wandering what type of ventilation system would be sufficient for this closet grow, i have three plants in there now that is really a prep grow but I want to get this problem fixed before I start my white rhino and cheese crops which will be next week so any help would be appreciated thanks

 

[JJ Bones]

What type of ventilation are you doing now?

 

[Cheeba420]

Just a little 7in fan to keep the air circulated but I haven't bought a vent system yet I was looking for a good suggestion because I also bout a 400w ipower air cooled grow light and do I need to buy two separate vent systems for the size of my closet or just one through connected to the light

 

[JJ Bones]

Okay so essentially there is no ventilation at all.

You can vent your room through the light, as long as you are not planning to run CO2

 

[Cheeba420]

Yea there's none essentially I was looking for help on what to buy cause I was doing reading all over the net about cfm's
no I don't think I'll need to run co2 I'm only going to have three plants in the room and I live in apt so I really can't drill into the ceiling

 

[JJ Bones]

You'll need an exhaust fan that is at least 200 CFM (your room is 160, additional 25% for corners)

You need to exhaust the heat out of the closet completely, you also need a source of colder fresh air. So you cannot simply exhaust into your bedroom from the closet because where will cold air come from? The heat will just be recycled.

 

[Cheeba420]

Would it not be good to have the exhaust high on the wall near the ceiling and the intake near the floor on opposite sides

 

[JJ Bones]

Yes

 

[Cheeba420]

How if the room out side the closet is about 20x15 and the air will be circulated, I'm just trying to understand.
And what should I do about humidity or it will be fixed with the heat

 

[JJ Bones]

It will be better then what you're doing now, hopefully the height different will counter act the heat build-up. You have to work with what you have if you cannot create ideal conditions. If you can use ducting to carry it outside a window in the 20x15 room that'd be great. However that large of a room may help prevent heat build-up.

 

[Cheeba420]

I was thinking of running a duct to the window but kind of sketched because my window faces a main parking lot of the apt complex and idk about that cuz office ppl might see it

 

[JJ Bones]

I understand, you would have to stealth the window and prevent light from leaking through, also smell would be a factor. You can just try venting into the bigger room and see what will happen.

 

[Cheeba420]

Yea that's what I was saying about venting into my room cuz of how big it was if I keep a fan in here to circulate air, I may be able to vent heat through the ceiling light

 

[Padox]

Ill try and show how easy this can be. I air-condition the room my two boxes live in for temperature reasons(outside is 36c) but have no need to bring fresh air in as I visit the room frequently. all that aside, I have a veg box and grow tent and this is how I ventilate them. Very simple and it works for me. You may need to make adaptions but good for idea.

The black thing hanging in the tent is the inline fan and the short piece of ducting with a bend is to stop light entering when I visit veg box at night. I inturn have ducts on the other side with a bend for the same reason letting air in from the negative pressure created in room. I find I have a 6in fan sucking air out and I need 14in worth of ducting at the bottom on he opposite side to let adequate air in to keep up with the fan. The following is the veg box

The first photo is the exhaust fan setup to suck air from in room and blow out side of box. second pic is the other end where the air gets sucked in and final pic of the plants in there and the exhaust fan to the right

 

[Padox]

I should mention also that to maintain a nice 24-26c in the tent I leave the intake and circ fan on 24/7 and the room its in needs to sit around 22c for this to happen. if I set my a/c to 24c my tent temp becomes 26-28c and so on. Your room is obviously bigger so just upsize on what I have and my light is only 400w but you have more space so that shouldn't be a factor.

 

[Cheeba420]

Yes this does help thanks, I think I have a pretty good idea on what I'm gonna do and just put a hole at the top right corner of the closet for exhuast and one on the lower right for intake its about to start getting cold I hope cuz I live in southeastern USA so the open window will supply cool fresh air. Which fan would be better a inline or squirrel cage I see you use both and wondering if it was for specific reasons or more logic because of size and fittings

 

[Padox]

the inline definitely moves more air more effectively and is easy to connect and adapt via ducting and sheet metal work. To be honest I had the small squirrel cage lying around and built it in to do what I needed. I used it on a 2x4x5 cabinet and I don't believe it worked well enough. It is a crappy plastic one tho so im sure a higher end product would move more air thus be more efficient. 'Centrifugal' inline fans move epic amounts of air silently but cost a bit more. my inline fan is literally a 6in computer fan mounted inside a plastic duct... this cost me $60 and still moves a lot more air than the squirrel cage.

 

[Cheeba420]

Yeah I think I'm gonna go with the inline fan plus I have a cool tube so I pretty much have to get one. Ill post some pics of my grow room when I get home to show what I'm working with

 

[Padox]

cool.