Help ventilation

I have a tent in a room that is cooled by air com it's a passive air intake is the air con air providing enough fresh air

Anyone ?

Ok first I need to know if there is any source of fresh air from outside? Plants need co2 to photosynthesise. If you're drawing conditioned air from a sealed room and exhausting into the very same room then I'd have to say no, the available co2 within the rooms airmass will eventually be depleted. However if you are exhausting out of a window/vent/air brick then this leads me to believe that there will be some negative pressure both in ur tent and in the air conditioned room that will pull fresh co2 rich air into the tent.

It's a bit lyk hydroponics, imagine a sealed room as a recirculating hydro system as the plants use up the nutrients you're left with a solution that is lacking in certain necessary elements so you must replenish them by means of topping up your res or doing a full res change. This is like the co2 in the atmosphere, if you're constantly recirculating the air then it's co2 content is becoming less and less.

Now think of the standard negative pressure system you wil see all over this site. This is like a drain/run to waste system, nutrients are fed to the plant rootzzone where they replace the depleted nutrients before being drained away never to be seen again only for the same process to be repeated over and over again. This is similar to the process of air being replenished via negative pressure. There is a constant flow of fresh air through the tent because the exhaust is getting rid of old air which contains less co2 and the passive intake is replacing it with fresh air.

Went off on one there didn't we ? Lol. The top and bottom of it is. If your negative pressure is drawing in fresh air from outside the room then chances are you will have enough, if all you're doing is recirculating that old air then chances are you're plants aren't getting enough co2.

I know I webt abit crazy there bro hope it wasn't too hard to understand and I hope it helped.

So I have a air con in a window blowing in the room and my tent in the room has a passive setup so the air goes in the bottom out the top through my exhaust fan and out the window

You're fine mate I wouldn't worry about it, are you having any problems that might lead u to believe there was something wrong with ur air content?

Na I just had to be sure cause I've fucked to many grows by not asking a simple question

oh and thank you for that

Turbo head said:

Na I just had to be sure cause I've fucked to many grows by not asking a simple question

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You and me both mate lol, it's all part of the learning curve. (Atleast that's how I've justified dead plants in the pAst)

Turbo head said:

oh and thank you for that

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No bother at all friend

Blue brother said:

You and me both mate lol, it's all part of the learning curve. (Atleast that's how I've justified dead plants in the pAst)

No bother at all friend

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What setup do you have man

You must have circulation at all times. Cool or not. Dead air is not good. Even if the temps are textbook perfect you must have moving air exchange.

hotrodharley said:

You must have circulation at all times. Cool or not. Dead air is not good. Even if the temps are textbook perfect you must have moving air exchange.

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What do you suggest

Anything to keep air moving. Cheap box fans work great. Computer cooling fans aren't worth squat even in a tent.

The plants use the atmospheric gasses they live on like we breathe all the oxygen out of a room if it's sealed. Everything needs a constant supply.

So pull fresh air from out side ?

So the air coming out of the aircon is worth squat ?

It's good but I can guarantee you it isn't moving enough air around the entire plant. One cheap box fan to keep your cooled air (which sinks) moving to displace the heated air (which rises) in the room for a more even temp. Refrigerated air works by continually recirculating and removing the heat from the SAME AIR! It is not fresh air.

hotrodharley said:

It's good but I can guarantee you it isn't moving enough air around the entire plant. One cheap box fan to keep your cooled air (which sinks) moving to displace the heated air (which rises) in the room for a more even temp. Refrigerated air works by continually recirculating and removing the heat from the SAME AIR! It is not fresh air.

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I second this. If there is no means of drawing in fresh air to replace depleted air then the air your plants are breathing wil have little co2

Turbo head said:

What setup do you have man

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I use a crawl space as a kind of lung room and exhaust into it and draw warm air from it when it's cold along with fresh air from a window. I have 1 8" exhaust fan 1 6" cooltube fan 1 5" intake fan and 1 5" fan to blow hot air from the lung room back into the grow room. I also periodicaly blow warm oxygen rich air from the lung room into my house which keeps my house running at a positive pressure, even though my grow room is at negative pressure

So what do I do ?

Somehow you must draw some fresh air in. The AC will still cool! That is good and needed. However you then have to exhaust some of your room air. That's where setups like Blue Brother describe come in.