New room set up, co2 and ventilation?

Hi, i've been thinking about how to set up my amazing and big new grow room! I want to get an idea if this set up has a chance to work. I've been doing so much reading and research and there is so much contradicting information! I'm a fairly new grower, my grow space is in a hot, south facing, poorly insulated old house, in southern california.



It's a 10'x14'x8' bedroom, with six big 450w leds, a portable 14,000 btu AC that is getting exhausted outside thru the ceiling. My windows are covered and insulated. On the other side of the room, there is an existing passive air intake, that is connected to the living room, it's 4''x4''ish so it's pretty small, but you definitely feel air coming in when the AC is running



Can i roll with it just like that? Count on the AC to cool the room, exhaust enough air to suck enough air thru the small passive air intake? The co2 monitor in the room reads 750 ppm but i only have a couple smaller plants right now. Keep in mind i usually and grow in 90f+ and 85% rh ballpark, so i'm not too worried about the heat more the air exchange and co2 levels


I just feel like that would be so little air exchange compared to my last grows, and i don't want to make more holes in the walls, or make it a sealed room, buying and installing a new split AC and getting co2 refills is just not happening because i have no car, thanks for any advise!

Doesn't sound like you have the light to use co2. You need about 800ppfd before it does anything really. The planet probably has enough co2 without you adding more.

I bet the exhaust hose is bigger than that 4x4" inlet. Meaning air is coming in from other places or the aircon may overheat

Doesn't do any good to supplement CO2 if your room isn't sealed. You will just be venting it outside .

Also portable AC is a very bad idea for a grow. It will exhaust odors as it vents outside. Invest in a window shaker or mini-split and save yourself a lot of hassles.

_growbynumbers_sub_co2 in ventilated space .. PS remove this line if you quote this message in reply



with standard tent setup the air is exchanged three times each minute.


IF this is true for you then most (meaning 98% or so) of co2 generated will be vented into atmosphere and will be a part of the climate issues / global warming. plants would use the remaining 2% or so.


“Emissions of 130 g CO2/km correspond to a fuel consumption of around 5.6 litres per 100 km (l/100 km) of petrol or 4.9 l/100 km of diesel.” from EU-site …


So a bottle of 20 kg of co2 vented to air amounts to minute gains and harm equal to driving 1kg = 750km >> 20 kg = 15 000 km. (= 10 000 miles)
…
So please … only used co2 in sealed environment.

f-e said:

Doesn't sound like you have the light to use co2. You need about 800ppfd before it does anything really. The planet probably has enough co2 without you adding more.

I bet the exhaust hose is bigger than that 4x4" inlet. Meaning air is coming in from other places or the aircon may overheat

Click to expand...

Yes the AC exhaust pipe is bigger, it's 6'', and the passive air intake is smaller, no good?


Also i'm definetly NOT trying to ADD CO2, i'm just wondering if, with that portable AC/passive small intake combo, it would just magically work without me having to make more holes, or seal up. thanks!

RockinRobot said:

Doesn't do any good to supplement CO2 if your room isn't sealed. You will just be venting it outside .

Also portable AC is a very bad idea for a grow. It will exhaust odors as it vents outside. Invest in a window shaker or mini-split and save yourself a lot of hassles.

Click to expand...

I'm not adding CO2, but i was thinking, maybe a good inline carbon filter for the AC exhaust could be enough to eliminate odor?

Even if you're not running CO2 I'd seal off your central AC to keep the smell from permeating you whole house. Add a dehumidifier to your portable AC and have at it. There are so many air leaks in buildings that even with a sealed room your plants will get adequate CO2. Controlling the temp and RH are the challenges.