i tried this without much success at my old building. some things i learned in the process...
i had a 5 ton ac in my lung room open on the bottom and ducted out the top, it went into each room with 10" hard ducting and had 1 drop per 100 sqft. There were a total of three room, one of them 500sqft the other two were 300sqft and 200sqft. I had 20 lights flipping from one room into the other 2 smaller rooms of 12 and 8 lights respectively. Inside the lung room were a few propane burners to maximize co2 for the room needing the ac the most. that in theory would have been the room with the lights on. 5 tons should have been enough for 500sqft with 20 lights all ducted but it wasn't. so we enlarged the ducting to 16" and instead of allowing the lung room to breath freely through the walls we then ducted that as well directly to the lung room and put in motorized dampeners on the entire operation and zoned it into 3 rooms. still didn't work. moved the co2 burners into the individual rooms and still had problems. our lung room could not breath enough to handle the volume of 8000cuft. i had low ceilings at the place to start. finally we closed off the lung room and moved the ac above the rooms ducted directly to the return of the ac again using more dampeners. this worked to a degree. but that's not the point... what i learned...
i believe the lung room has to have a tremendous amount of negative pressure
at nights plants need the ac just as much as they do during the day as when the lights turn off it takes a few hours for the entire room to cool down
the ac acts as a dehu all night long as well
the lung room should be as small as physically possible as it is adding volume of air to maintain
i'd say get a second dehu as it's the first 2 or 3 hours of darkness where humidity spikes,
if you're building a lung room purely for the sake of saving on propane burner and dehumidifier i'd scrap the lung room idea and get the additional components to make each room ideal and just use the flip for the sake of lighting. perhaps for moving the air through the lights you could devise a flip system or plenum so that you maximize airflow through the lights and not duct 4 of them in a row. from my experience 2 lights in a row max otherwise you're just blowing hot air on a hot light bulb.
just a few thoughts from my experience
Awesome, thanks for your advice. I'm having a little trouble picturing your setup. So you had one room with 20 lights, which flipped into two rooms of 8 and 12. All lights were ducted, and you had 5 tons of A/C plumbed through the rooms through 16" ducting with a drop every 100 ft2. What were you using to draw the air from the A/C into the rooms?
You mentioned that the lung room should have negative pressure. Would it be better to be pulling air from the lung room, and the lung room would have a passive intake?
The lung room is really to utilize the A/Cs for both rooms. A second co2 burner is really not a big deal, but if the room is already exchanging air with a lung room, I don't see any reason why the co2 generator couldn't be in the lung room. I can justify buying a second dehumidifier, although I'd rather try and figure out a way to utilize the one I have since I know it can handle the humidity for both rooms combined. I'd rather not spend 1 to 2 grand on a capable dehumidifier if I don't need to.
The room the equipment is being pulled from is an 8k bare bulb sealed room with the dehumidifier, ballasts, and co2 burner all in the same room. The room had low 6.5 foot ceilings and measured 12x24. The A/C could keep the room at 80 without working too hard, probably due to the fact I had a blower in each corner of the room (two dual zone A/Cs).
So I'm not sure if I really need to duct the lights, especially if the rooms are going to have more cubic space than the one they came from. The A/C, dehumidifier, and co2 burner should be able to supply both rooms adequately. I'm hoping its just a matter of designing the lung room properly. I could put the reflectors sideways and duct 2 lights at a time, which I might do. I'm sure a lung room is less efficient than having the A/C handlers directly inside the flower room.
I do have a third, single zone 2 ton mini split I can use, but I don't think I have the amperage available to run it.