CO2 + Negative Pressure?

[waltwalt]

Anyone that uses CO2 enrichment could probably answer this.

How do you maintain negative pressure on your room if you are pumping CO2 into the room?

Do you keep your exhaust fans running on low? That seems like a good way to waste a lot of CO2.

Do you just seal the room as best as possible and hope the added pressure doesnt cause it to leak out your air intake?

If you do have some method of doing this, how are your air intakes setup? Baffled? Damped?

-ww

 

[sparkjumper]

I use a co2 burner in a sealed room.By sealed I dont mean hermetically airtight,I mean there is no intake or exhaust.Simply a window AC and a dehumidifier especially for the dark hours

 

[waltwalt]

Ok. I am planning on going with CO2 enrichment and cooltubes, so I had planned on two separate ventilation paths, outside > lights > fan > outside for the cooltubes, and then an intake/exhaust with filter. But now it looks like I'll run one ventilation path for the lights, add some extra intake to provide for positive pressure in the lights and leave a big fan/filter in the room on recirculation to keep the odor down.

 

[noone88]

You can run a sealed room or semi-sealed room.

Sealed room is no active intake/exhaust. If you're running air cooled lights, then you would intake/exhaust lights on it's own loop. But be aware that the lights and ducting are not perfectly sealed so you will have some grow room air passing through the lights. Not much however.

A lot of us run a semi-sealed room, which is active intake/exhaust during the night cycles.

Any CO2 burner is capable of incomplete combustion, such as carbon monoxide. Venting out all the grow room air through a filter during the night cycle will take care of any "bad gasses".

Lastly, for a CO2 environment, you will need active AC cooling (unless you're fortunate enough to live in a cold environment). In order of worst to best is portable ac unit (dual tubes) -> window unit -> split AC unit.

 

[waltwalt]

I've got a 12,500 BTU split AC/Heat pump from Ramsond.
And I plan on using bottled gas with a regulator/controller.
Also running the lights on their own loop, straight in and out, I'm going to try using positive pressure to keep the grow room out of the lights. By this I mean I am going to reduce to a 4" Exhaust and use a 6" Intake.
Then just run a carbon filter/fan recirculating the air in the room. If the 6" intake 4" exhaust doesn't provide adequete cooling (2x1000w 6" cooltube fixtures) then I will step it up a bit, but for now that's what the plan is.