maintaining negative pressure while using CO2?

[CarharttKidd]

My current project has a 4" passive intake, 6" carbon scrubbed exhaust, and an 8" air cooled 1kw hood w/ its own fan. Im going to get a CO2 If you all have another idea to keep the stink on the plants and not in the house other than maintaining negative pressure in the box, I'm all ears.

 

[cabanetforester]

Seal your lights, seal your grow area, save your co2.

Keep the environment as constant as possible (1500 PPM constant during lights on).

Humidity and heat will be your challenges in a sealed space. I have humidity as high as 85% with lights off. However, I only do it early in flower and because I'm experimenting

85% RH is TOO HIGH! It will mold you.

If the lights and space are sealed the smell should stay inside. I would set your carbon filter and fan in the space so it's only filtering/recirculating the grow space air. CF

 

[CarharttKidd]

Yeah I dont have the cash for a mini split or window a/c nor do I have the cash for a dehumidifier. Otherwise, my grow would be sealed.

 

[Albert Hofmann]

Yeah I dont have the cash for a mini split or window a/c nor do I have the cash for a dehumidifier. Otherwise, my grow would be sealed.

Negative pressure requires an exhaust fan running 24/7...this makes using CO2 a COMPLETE waste of time
Properly done co2 is an expensive investment...sounds like your not ready quite yet. Outside of a sealed room, neg pressure is the only effective method of odor control IME. Forget the co2 for now and add it when you can afford it. CO2 is a great addition, but gram a watt numbers can be reached without it...worry about your nutes & ph first, lights, fresh air (this is easy with a 24/7 fan)

 

[CarharttKidd]

I have a controller and a decent generator for a bigger set up I had that I am ditching for a co2 regulator. If I can ditch my portable A/C, I'll def. have the cash for the window a/c and a dehumidifier. I was really just looking for a temporary fix until I can finish the sealed room.

I know that having a fan exhausting a room 24/7 would defeat the purpose of CO2. My controller will kick off the fans while the CO2 is running, but I know with a passive intake, its still not very efficient. Thats kinda the point of the thread.

 

[Albert Hofmann]

Man, if you are willing to cycle you fans off (neg pressure stops when the fan stops) when the co2 is running then go for it. It'll be less efficient but will work. However, like I said above, nothing else works for odor like neg pressure...so your house will stink to some degree, regardless of what other steps you take.

May I ask why you are so hell bent on starting with co2 immediately? Odor control is wayyy more important than co2. So, I say get your grow goin (you have everything you NEED) and add CO2 when you can get everything required to make it work correctly .02

 

[cabanetforester]

I would get the DH before getting the AC. Seal the room, run all your stuff, lights, pumps,DH .etc then check environment readings (temp/RH).

Sounds like you've done your homework, your just jumping the gun a little on the gas.

If you can get your temps to 85f+/- when everything is at it's hottest you can probably pull it off without the AC.

IF you have an 8" inline fan cooling your light you can probably do it without AC this time of year.

The key here is getting creative with your ducting and using ambient temps from another room/outside etc.

You could run a non insulated 2 into 1 with your ducting that has the cooler air running through it. Anyway that would be for a sealed space with no passive.


Not exactly what you asked for. What are your specifics?

 

[_Dude]

Anybody ever run a sealed CO2 room/box with air cooled lights? Lights intake and exhaust outside, carbon filter and blowers recirculating CO2 while removing odor?

 

[BlindDate]

That is a tough one. Seal the room as best you can and then use a natural gas CO2 burner so that all the wasted CO2 will not cost so much. Vent the room very slowly (through the air cooled burner) to maintain neg pressure. This will also solve your humidity problem (I'm assuming you have a good AC unit). Of course you can vent like crazy when the lights and burner are off.

I say to use a burner because tanks would become way to expensive and bothersome what with the constant venting. This is a balencing act my freind. Get it right and reap the rewards. Get it wrong and stink up your house and go to jail.

 

[Deviant420]

If you can get your temps to 85f+/- when everything is at it's hottest you can probably pull it off without the AC.

For perspective, I run low 80's during the winter now (20-30's day, single to teens night) bringing in cold air @ 475cfm and open (not a closed system) exhaust through 2 1000k hps and into the carbon filter just outside the 'room' but still in the room. I built a room inside a room.