Air flow and co2

Hello all,

I have a 6'x12' long shed separated for veg and flower. the flowering room is 6x6x7 foot give or take. I have a max fan 6" pulling air from the out side through the veg room into the flowering room and pushed through a small phresh filter. I also have a fan tech fx6 hooked up to a can filter 33 which sucks the hot air out of the flowering room.

I have a sentinel chhc-4 that i had the fx6 hooked up to to empty the room out when it hits 76 degrees and the max fan which is pulling air from out side hooked up to a timer, and brings in air every hour for 15 mins. well long story short i am going to being running co2 and do not want my co2 getting sucked out. So i disconnected the fx6 and carbon filter and swapped it for the max fan intake to cool the room down. the sentinel know controls the air intake when it hits 76 degrees and cools the room down rather quickly and brings more fresh air in.

My question is will this be adequate air exchange for healthy growth? I also plan on running 1500 ppm co2 x 2 1000 watt digis, not to worried about smell at the moment. would this be considered a sealed room setup as i am not pulling any air out of the room but filling it?

Any help much appreciated thanks

I have the same controller and set up. I use a 8" fan with carbon filter as my exhaust and a 4" as my intake. My room gets up to 87 then down to 83. Takes about 10-15 mins every 45-60 mins. Then my co2 kicks on when it reaches 83. In summer I am forced to use AC so I don't use my controller. I just use a 18k btu window AC and my co2 monitor / controller. U just want to make sure u have a smaller intake than exhaust or else you will have humidity issues. Oh and I also have a 70 pint dehumidifier

I guess Im not following. You say you are filling the room with fresh air, but not venting it? If thats what you said, then it's venting somwhere if you are bringing in fresh air. Sealed rooms nothing goes in and nothing goes out unless its on it's on a seperate loop sealed off from the grow space, ie sealed hoods exhausting, water or electrical lines.

As far as air exchange goes, if you are boosting with co2 you dont need any fresh air, other than maybe for your own comfort. The plants dont breath like we do, so venting the room isn't neccessary when you are manipulating co2 levels.

rarebreed619 said:

would this be considered a sealed room setup as i am not pulling any air out of the room but filling it?

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Unless you are constantly increasing the air pressure in the room, there is no way to take in air without expelling air in exchange. A sealed room is just that - nothing in or out. You have to break the seal to enter and leave, but it is best you do that as little as possible otherwise you start to loose the benefits of strict environmental control.

CO2 enrichment near the plants can still benefit them, but any exchange reduces the CO2 before the plants can use it and thus reduces the benefits. Air cannot come in (beyond a slight pressure build up) unless it is exchanged.

spandy said:

As far as air exchange goes, if you are boosting with co2 you dont need any fresh air, other than maybe for your own comfort. The plants dont breath like we do, so venting the room isn't neccessary when you are manipulating co2 levels.

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Yeah - fresh air is important for the unsealed room. But when you are in total control of the environment (sealed room), you refreshing what the plants need with the added CO2. But remember that air circulation is important in either case.

spandy said:

I guess Im not following. You say you are filling the room with fresh air, but not venting it? If thats what you said, then it's venting somwhere if you are bringing in fresh air. Sealed rooms nothing goes in and nothing goes out unless its on it's on a seperate loop sealed off from the grow space, ie sealed hoods exhausting, water or electrical lines.

As far as air exchange goes, if you are boosting with co2 you dont need any fresh air, other than maybe for your own comfort. The plants dont breath like we do, so venting the room isn't neccessary when you are manipulating co2 levels.

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Not trying for a sealed room but if i had to guess it would be venting into the veg room, that is directly in front of the flowering room. I split a 12 ft shed in half and when the inline kicks on i can see it push the door out a little. I made a double door with panda film and velcro the entire frame on both sides kinda looks like a balloon. But it brings in air alot more now which should be good for the plants? plus the extra co2 i will be adding. Just wanted to know if this would still be enough for healthy growth? As i am using the cold enviroment to cool my room now, which takes about 30 secs to drop my temp back down with the sentinel (75degrees) compared to pulling hot air out of the room through a carbon filter. my experience with grow tents i have used in the past would suck all the co2 i just pumped in my room out when sentinel kicked on to cool the room. so by cooling the room with the outside air and not pulling it out of the room would hopefully keep more co2 in the room.

rarebreed619 said:

so by cooling the room with the outside air and not pulling it out of the room would hopefully keep more co2 in the room.

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Take a balloon. Now fill it with some air. Keep doing that without pulling any air out of the balloon. Eventually, it will break.

If your tent does the same thing - expands until it bursts, congrats! You've pulled air into the tent without pulling any out, until it exploded at least. If your tent just puffs up a bit, either you are no longer forcing any air into the tent - things are at a standstill - or you are releasing air from one or more leaks in the tent.

Either you have a sealed room or you do not. If you don't want a sealed room, that is fine. But think about the balloon - there is only so much air you can pull in before you need to exchange air. And when you exchange air, you are sucking out the CO2.

I think he probably has enough air leaks and whatnot that having an exhaust port might not be completely necessary. Although your fans wouldn't have to work as hard if you did cut out a port somewhere.

But doing it the way you are doing, and using cold air and as quick as it cools the room down, your co2 loss will be noticable, but still effective. Im now getting about 4 weeks out of my 20lb co2 tanks in a similiar size space. BUt hey, co2 is cheap, even at 25 a bottle I'd replace them every week if I had to.