CO2 into a neg pressure bloom room.. help!!

[guyonthecouch]

Got a slight dilemma here and am looking for some advice from the pros. I'm trying to add CO2 injection to a bloom room that is already setup and running. The room was setup to run under negative pressure and changing it to a sealed room, although technically an option, it not what I want to do.

Details on room:

9' x 20' with 9.5' ceiling. Room is split down the middle with two sheets of black & white poly as there is a flip-flop running the room. 4 - 600's on each side in horizontal air-cooled reflectors. Each side has a 4' carbon filter at one end that is being pulled through, then through each hood with 6" flex duct, then each of the two sides go into a "wye" that combines into a single 12" flex that goes on out to the attic (so air flow goes filter ->light ->light ->light -> light -> "wye" -> fan -> out through roof).

The negative pressure is fairly strong in that when you have the door to the room just barely cracked, you can hear the air rushing in the door. There is a window AC installed in the rear wall. I want to add CO2 (i think i need a burner instead of tanks, don't really want to fuck with tanks anyway) but I will need the exhaust fan up in the attic to turn off while co2 is running and likely stay off for a bit after the room reachs 1500 ppm. I need a controller that can a) turn off my exhaust prior to turning on the burner, turn the burner off when it gets to the specified range, then turn the exhaust fan back on after a set time of co2 being at 1500 (i was thinking maybe 15 minutes later, something like that). That all needs to be automatic too. I don't mind spending for it but I'm open to options.

I thought of maybe a relay of some kind that would basically turn off the fan once the burner's controller relay gets kicked on (so like a normally closed relay that opens when powered) but then doesn't turn back on until some minutes after the burner relay goes off. Does anyone run CO2 in a negative pressure room?


Another question: How long does the room need to stay at 1500 ppm of CO2 for the plants to uptake the extra CO2? and how many time of day does that need to happen? I was thinking maybe bring it to 1500, keep it there for 15 or 20 minutes, then exhaust and do that whole cycle like every two to three hours?? What do you all recommend??

attached is a rough sketch of the room (sorry for my shitty drawing)

thx dooods

 

[guyonthecouch]

this seems to be able to do what I need, but it's pretty salty and likely overkill for what I need.

 

[purpleberry]

You need to seperate your air flow for the lights to go outside air>>light>>light>>>outside air so you dont suck the co2 out. you dont want to stop airflow in the air cooled lights at any point. If you have to be concerned with smell, You will need to make you room really air tight and maybe still have some negitive presure sucking threw a filter. Ive found that the only way to control smell is to have a little neg presure. Which does eat co2 but not so bad it cant be done.
I just took a room and swtched it back to how you have it for a few reasons, One sucking the cooler air from the room keeps the lights cooler than outside air in the summer and brought temps down, And it created the neg presure to keep the smell down, Then i put a fan speed controller on the fan all the way dwon to slow the air removale dwon, Going to try co2 and see how fast it gets sucked out.
Not sure how much i helped you lol

 

[bobbybrown]

You could purchase these 2 pieces of equipment:

1. CAP AIR2 - Environmental controller that will activate your exhaust fans at a specified temperature and humidity.
2. CAP PPM2A - Fuzzy Logic CO2 Controller that you can connect to the AIR2. When your room exhausts, the CO2 automatically shuts off and refills the room when the exhaust fan turns off.

 

[bobbybrown]

If you let us know what your priorities are, you can do anything with the right equipment. Let me know what your specific question is and I will try my best to come up with a solution for you.

 

[Dr Melrose]

Allright im going to try and help. Purple is right,youre going to need some controllers. Ill tell you what im doing and see if you can use any info. I have air coming from outside,1 fan pushing through the lights, other end 1 pulling,i have 4 1kwatts,air exiting outside. nat gas co2 burner with an atlas ppm controller,it comes on with the lights and shuts off with the lights,photo cell. I also have a 12,000 btu inroom a/c and central air piped in with a damper for when needed. In room de-humid, a 8in. inline w/carbon filter to exhale during the dark hours,it runs the whole time the lights are off,its on a timer and speed controller. You can run the 8in. while lights and co2 are on (reallll slow) if you have the gas co2,cause it will pull out some co2. The down side is your co2 will kick on more frequently thus creating more heat. I put the timer to exaust every 3 hours w/light on. Just to exchange air and bring down humidity to be safe. My room is allways neg press. Hope this helps some, if not i would be happy to answer any questions you might have with more info on one specific thing.