sealed room, does it have an exhaust?

im in the process of changing my room to a sealed room. all my lights use cool tubes and are exhausted independently from the room. they only suck in air from my house, and blow that hot air outside. i also have 2 more inline fans, one brings in fresh air from my house into the grow, the other dumps the old stale hot air outside. i run these 24/7 due to high heat issues.

now heres where the game totally changes. i have a hydrogen pro natural gas co2 generator all hooked up good to go. i also just got in a mini split ac which i will install this week. for anyone not familiar with it, it's a quite expensive air conditioner made of 2 main pieces. one you put inside your room for cooling, it sucks in and blows out the same air in the room but greatly cools in. it doesnt mix any outside air like a normal window or stand alone ac. the other piece of the mini split ac gets placed outside kind of like the compressor for a central air ac. they 2 pieces connect with wiring and copper coil. they use only 10 amps or 2/3 the power of a normal ac for only 2,000 less BTUs (normally ac is 14,000 mini split is 12,000) i also have a sentinel controller and timer to control everything. im also going to do my best to seal the entire room.

my question is, do i still need an exhaust? yeah im going to be in and our of the room like 5+ times a day or more just like i am now and new air will coming in each time that door opens. however on the other hand my friend is telling me you still need an exhaust to the stagnant air. i just dont understand what exactly i would want to be exhausting? i mean my mini split keeps my room the proper temp. my sentinel controller will be keeping my co2 at a near 1500 ppms, even if i am exhausting and wasting a bit. i know plants need oxygen also, especially roots but they also produce that themselves. my dehumidifier and ac will keep humidity levels in check. my mini split also has a filter to help remove mold spores. so why do you exhaust a sealed room? do you really have to? i mean if everyone is telling me it's better to after getting enough info im going to do it but i dont really quite understand why? some ppl are telling me to replace the entire air in the room every hour. i know you want to do that in a normal grow, but is that also true for a sealed room? it shouldnt be hard to seal, it's only 9x9x8. 4 600w hps lights in that small area also LOL.

thanks in advance bros. +rep for any help

Yeah thats generally what I have heard also, I've heard air exchange should be occurring every few minutes or less. I guess it depends on the size of the room you are working with as well. I think it just helps having fresh air in there. But I have never worked with a CO2 generator but from the way it sounds, you really wouldn't need an intake. But having an intake would give you a better air flow I think regardless if you have fans in there.

some of the best rooms around have no in or out venting. pretty sure thats the key to being sealed.
but i have a exaust set up on my chhc4 for cooling just in case. i have a damper on that so it stays closed when not in use.
also alot of those totally seald rooms scrub air.

no intake what so ever

a mongo frog said:

some of the best rooms around have no in or out venting. pretty sure thats the key to being sealed.
but i have a exaust set up on my chhc4 for cooling just in case. i have a damper on that so it stays closed when not in use.
also alot of those totally seald rooms scrub air.

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thansk guys for the fast response. yeah thats exactly what i thought, it's supposed to be sealed. but my buddy keeps swearing to still have an exhaust. my mini split ac has a built in mold filter. also i have a pretty big carbon filter that i havent been using. i suppose i could just set it on the floor with a fan and let it scrub. i have a 745cfm 8'' inline fan im not using atm. i dont worry about exhausting stinky air outside cause the area where it exhausts to isnt accessible to anyone. but if it should be kept sealed then thats what im gonna do. just keep the inside air scrubbed.

also what about carbon monoxide produced by the co2 generator? will it produce enough to cause any ill effects on my plants or ppl entering the room. or will it not produce levels high enough to be of any harm. i plan on getting a co detector either way.

T.H.Cammo said:

I don't understand, in the first paragraph you say that you already have 2 fans (1 blowing in and 1 blowing out). Then you ask if you still need exhaust (do you mean more exhaust?).

A sealed room is sealed! No intake - no exhaust. The Cool-tubes don't count because thier intake and exhaust are external to the room itself. Your generator produces co2, your plants produce o2, and the door opening every so often produces all the ventilation you need. If you are purposefully transfering air into and/or out of the room; it's not really sealed, is it?

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i have my exhaust for the room run 24/7. i was told in a sealed room u still need exhaust but only run it long enough to bring in fresh air every hour. didnt really make sense to me either cause then yeah you're right, it's not a sealed room. he tried saying you still need to replace the stagnant air. i said what stagnant air? its just co2 and o2 in the room. the only bad thing is the co from the generator but im sure its a small amount. i dont think he really understood what he was talking about.

thanks for clearing that up for me bro. thats exactly what i didnt understand myself. i figured a sealed room is literally sealed. now my friend is trying to tell me you still need to exhaust which didnt make sense to me. im not sure why he thinks this. hes a cool dude thats been growing for years does a great job, has more experience than me, but on occasion i find out he's wrong about some things like this.

im sorry for the confusion on the first paragraph. i will try and explain it better. my lights are sealed and vented entirely outside the room or as you stated, external. i have another exhaust fan that constantly runs in my room blowing the air outdoors. this helps cool my room and bring in fresh air. i have another intake fan on my door which constantly runs to bring in fresh air constantly when the door is shut. otherwise i just leave the door open with a box fan in the doorway when the light cycle is on. my NG co2 gen is off right now because it produces too much heat. im waiting on a 1/4 hp chiller for the 55 gal res for it. my mini splitter just came and i will hook it up this week. since my temps will be under control, i will be able to keep the door closed. i didnt know if i should remove the intake and exhaust fan for the room or not. i figured im better off going with a sealed room. not sure how the heat will be with my co2 generator but it will be under control once it has the chiller hooked up to it. i figured a sealed room meant literally sealed but then my friend confused me when he was trying to tell me that you still have an exhaust which he was wrong.

thanks for the help bro. you and that other guy really helped clear this up for me. think i'll be completely sealing my room up then. gonna line the whole thing in poly tarp also. only exhaust fans will be externally for my lights. then maybe 1 sitting on top of a carbon filter just scrubbing. no air in the room will be exhausting.
got it now!

just wanted to follow up on this. i contacted hydrogen innovations and they basically said the same thing. they generally seal their rooms. they said you can exhaust it and they recommend to once a day, but you don't have to especially if you're going to be in there every day. i asked about o2 buildup and they said it would take weeks. thanks everyone again.