Closet ventilation- air intake and exhaust

Im setting up my first closet grow but have one last question about ventilation.. I already have my carbon filter exhaust set up but im wondering about bringing fresh air into my room for my plants. Do i need to put a vent into the grow room too allow for fresh air to be pulled in or will the air be refreshed enough just by me opening the doors to check my plants? its a very small growing space, only about 1.5 feet deep and 3 feet wide with 8 ft ceiling. Ive been researching all over but cant find anything specific and dont want to start off wrong. looking forward for feedback so i can get everything set up tomorrow and taking pictures to start my grow journal!!

You need a fresh air intake yes. A passive intake vent should be 2 - 3 times larger in area than your active exhaust vent. Put it down low to get cooler air.

We may have a similar situation, but I'm not sure.. I have a small cab 2ft x 1ft x 3 high. I placed this cab inside a 4x4x8 closet with a door. I put it in the closet so it's more stealthy and so light and smell won't leak out and alert my neighbors. Inside my cab I have a good carbon filter that blows out. I have holes for passive intake near the bottom. I also added a fan to provide more fresh air intake. However, I am running into heat issues.

The problem is that I'm just recycling the same hot air inside the closet. My scrubber pulls the hot air from my box into the closet space and the fan just drags it back in. My box heats up really quick no matter what I try. The only solution is to keep the door to the closet cracked and the door to the cab cracked with a fan blowing cool air from outside the closet into my cab. By doing this I lose a lot of my stealth, but my box stays around 1-2 degrees above room temperature of 72 degrees.

What I have decided to do is make a 4" inch hole in the front of my cab and attach a vent hose to the fan that sits outside of the closet. I'll just run the vent right into my box. At least this way I can close the doors on my cab and just keep the closet door cracked 4 inches.

Not sure if this helps, but hope it does.. Good Luck.

That heat must go somewhere... recirculation is a commonly overlooked factor with tent / closet grows. As temperature differential shrinks your grow gets hotter.

ok thank you!! i wasnt sure because i wasnt sure if that would effect odor leaking out and have seen so many different set up and figured theres gotta be a proper way. Ive seen many that only pull fresh air in at certain times of the day but didnt want to hook up another controlled fan to pull air in but the passive vent will be nice and easy. And i dont know how my closet will do with heat yet. I was thinking of venting my carbon filter directly up and out through my attic so the heat isnt pushed in the same area but im concerned how well the carbon filter will eliminate the smell before pumping the air back outside through my attic. I dont want my neighbors catching a fresh wiff of some growing buds so im debating still venting back into my house. i have clones rooting now that i got off a buddy. Cant wait to be done so i can transplant and start tending to my girls.

You can put a carbon filter on your exhaust and if thats not enough run a carbon filter scrubber as well inside the grow room.

Best tip I can give on carbon filters, never undersize, bigger is always better here.

I do have a carbon filter but i only have limited space so i got as big as possible. ill probably get the carbon scrubber too once my plants start flowering. Thanks for the advice, next step is the set up tomorrow then once my clones got some healthy roots its time to transplant and start the fun

I messed with my fans and outtake all day. Moving my outtake to the top of my cab helped a lot with my temp issue inside my box.. I'd still like the closet to stay cooler though in case I want to add more lights.

You are right Snaps, I am finding that the heat needs to be vented out of the closet. I have 2 closets, side by side but completely separate. What I am considering is opening up a hole between the closets and venting into the unused closet. Either that or into the ceiling space. I'm not really sure what's up there though so tomorrow I will remove the cover to my bathroom fan and see what I can see....I live in an apartment, so I guess there may be some questions when I move out unless I can do some really good patch work

I'm trying to think of ways to create a vent without the light shining through. I've seen ozone generators before but would that do the job of replacing the air like the vent would do? And also I was alreading thinkin wat people will think of the hole in the closet if I can't patch it wen I move lol