Sealed, Multi-Chamber box for CO2

[GR33NL3AF]

I'm interested in constructing a sealed box that will house 1 CO2 generator and pump it into my 4 rooms rooms.

The build would be easy but setting up the automated on/off is what's going to be tricky..

I currently use CAP's Propane burners with the Sentinel Chhc-4 atmospheric controller to regulate. So I am thinking in order to power up the burner I will need to splice 3 additional outlets onto the generators power line and plug each into the individual room's sentinel but do I need an inline fan to draw the CO2 out of the box and into its appropriate room? If this is the case I need the fan to power up when the burner does, so I would need to double up at the sentinel.

Let me know if I'm making any sense, and if so, have you ever seen or attempting something like this?

Im sure @ttystikk will have some insight! ;)

 

[HookedonPonics]

My idea would be to set up a single co2 meter in the co2 Lung room that the burners in and keep it as high as you can and then pull 4 inline fans from the lung, one to each room and hook each rooms inline to each rooms individual co2 meter. You'd have to completely seal the lung room and have passive intakes from each of the flower rooms preferably on dampers that open when a room is on. Honestly it'd be a shitload of work to keep things sealed, IMHO id just buy 3 more burners it'd probably be about the same price also.

 

[GR33NL3AF]

My idea would be to set up a single co2 meter in the co2 Lung room that the burners in and keep it as high as you can and then pull 4 inline fans from the lung, one to each room and hook each rooms inline to each rooms individual co2 meter. You'd have to completely seal the lung room and have passive intakes from each of the flower rooms preferably on dampers that open when a room is on. Honestly it'd be a shitload of work to keep things sealed, IMHO id just buy 3 more burners it'd probably be about the same price also.

hmmm... I have 3 burners now but recently 2 of them crapped out and they're pricey to replace...Just exploring alternatives brother

 

[HookedonPonics]

It'll by all means work. You just have to make sure the co2 room is sealed tight and not pulling air from outside, or you'll end up exhausting all your co2. If you have a completely sealed co2 chamber and a passive intake from each room you should be golden. You might not even need a meter in the lung you might wanna just run it 30 min on 30 off an play with it accordingly. That'd save a few bucks

 

[ttystikk]

If you do this, you will need to use negative pressure to draw the CO² into the rooms where it's desired. Simple enough; just install the fan where the CO² duct enters the grow room. Plug fan into CO² plug on chhc-4, program CO² cycle for 'split', and voilá! Downstream part is done.

Upstream much more tricky; I'm assuming you have four bloom rooms and they run some kind of flip schedule, say two on and two off, plus veg on all the time? Assuming this is a close enough guess, you'll want a slow constant speed fan sucking CO² through your veg area. It must be constant so there is ALWAYS some fresh air for the burner. If no fan runs for a long enough period, the system could easily build up enough heat and gas to be dangerous.

So to brush broad strokes; run the burner low but constant on with auto shut off in case of power outage, with as big a plenum/lung area as you can. Put the burner down at floor level or close to it, so fresh air is assured. Make sure the fresh air inlet duct goes right to the burner. Make certain at least one fan runs at all times, may as well be for veg. Run a big 8" duct to each room and install a fan at the opening that sucks down the ducting and blows into the growroom. Control this fan with Sentinel. Control fan speed (not too fast, so burner can keep up and Sentinel can register it as it moves into the room) with variable controller and set it to low or medium.

Thank you, you just helped me figure out the same thing, only using my hot water heater, lol... no, Seriously. Why not? And if you live in the mountains on propane heat, ummmm... duh, right? The dual use of fuel is right here under our noses, only now we're looking at it a whole new way.

 

[GR33NL3AF]

Knew you would chime in @ttystikk !

This is perfect...Rather then let the CO2 burner run constant or on a timer, I think I am going to get an inexpensive controller to shut off the generator at a specific ppm.

TTY, you really think I will need an 8" fan? I was thinking 4" would be plenty..

 

[ttystikk]

Knew you would chime in @ttystikk !

This is perfect...Rather then let the CO2 burner run constant or on a timer, I think I am going to get an inexpensive controller to shut off the generator at a specific ppm.

TTY, you really think I will need an 8" fan? I was thinking 4" would be plenty..

Depends on distance and volume needed. Also remember that with suction, it can be harder to get a useful flow rate with small diameter duct. This is much worse if it's flexible duct, as that definitely increases drag.

Is this a couple of lights in a corner, or is it a large space? I didn't get that info, or did I miss it?

Moving on- the only way out could work is if you get a controller that lets you set it way high. Shutting off at 1500ppm will never let you catch up in the room. In practice this means a constant burn, maybe one of the four burners, and a bigger plenum. You already have CO² controllers built into the Sentinels; why balk at using them as intended?

 

[GR33NL3AF]

Depends on distance and volume needed. Also remember that with suction, it can be harder to get a useful flow rate with small diameter duct. This is much worse if it's flexible duct, as that definitely increases drag.

Is this a couple of lights in a corner, or is it a large space? I didn't get that info, or did I miss it?

I was going to set this puppy up to provide CO2 to 3 flower rooms and a veg space. Each room is roughly 12'x12' with 6Kw in the flower rooms and Fluorescents in the veg station. Average distance traveled to each room... 15-20'

 

[ttystikk]

See above for edit.

I think you will definitely want 8"ducting and muffin fans, because you need to move a lot of CO². Would be nice if you could route galvanized hard pipe outside in winter to chill it on the way to the growroom, eh?

 

[Tank333]

Ok, you've mentioned it twice now Tty... wtf is a muffin fan???

 

[squiggly]

Unsafe.

Burners require oxygen to function properly, sealing them in is bad. They must be fed with fresh air. Pulling a negative pressure on a room with a burner in it might cause the flames to go out.

 

[ttystikk]

It's the fat online fan that looks like a muffintop stuck on the duct. The canfans are duct sized. Both are axial flow fans.

 

[ttystikk]

Unsafe.

Burners require oxygen to function properly, sealing them in is bad. They must be fed with fresh air. Pulling a negative pressure on a room with a burner in it might cause the flames to go out.

There is an unobstructed pipe bringing fresh air directly to the burner at all times, and at least one exhaust fan for removing CO² will be on at all times, often several more. The veg section CO² supply duct would run 24/7 at a low rate to maintain good flow across the burner. Other rooms would pull from the system as their environmental controllers see fit. At no time would the burner experience a low oxygen situation that might cause the flame to go out.

 

[squiggly]

I would rather see a setup that runs positive pressure composed of fresh air into the sealed container. If sealed properly from there the CO2 will be delivered to whatever it's connected to.

It's important to size the enclosure properly.

 

[Tank333]

It's the fat online fan that looks like a muffintop stuck on the duct. The canfans are duct sized. Both are axial flow fans.

So just it's the different way the fan is designed? And a booster fan is different from both of those, right? I feel hella no0bish asking these types of questions. Lol. I always just called em' all inline fans. Haha

 

[ttystikk]

All these are inline fans, just different types.

 

[Tank333]

Mkay. Gotcha. Just never heard the term "muffin fan" before. Lol

 

[ttystikk]

I would rather see a setup that runs positive pressure composed of fresh air into the sealed container. If sealed properly from there the CO2 will be delivered to whatever it's connected to.

It's important to size the enclosure properly.

My concern about positive pressure is that any leak becomes potentially dangerous, where with negative pressure that won't happen. We're talking about a very small amount of negative pressure, maybe an inch of Hg...

 

[GR33NL3AF]

My concern about positive pressure is that any leak becomes potentially dangerous, where with negative pressure that won't happen. We're talking about a very small amount of negative pressure, maybe an inch of Hg...

If I hung my box from the ceiling and ran a 4" piece of duct and a 4" fan pulling air from under the house and pushing it into the box would that work? I would dial it down and put it on a timer..

 

[ttystikk]

If I hung my box from the ceiling and ran a 4" piece of duct and a 4" fan pulling air from under the house and pushing it into the box would that work? I would dial it down and put it on a timer..

My two cents says draw air through this system, never push any into it. Not sure why my gut is so strong in this one, but I don't like the idea of spent combustion gases leaking into spaces where people breathe or sleep.