Hello! Looking for advice on ventilation for my rooms,

I am currently adding on to my existing grow rooms.
The rooms are located in a pole barn (30x40).
For the first grow area I used the back 16’ of the garage, giving me a 16x30 area. I split that into 2 rooms and an “L” shaped hallway. Giving me a 13x15 bloom room and a 13x12 veg room everything has 9-1/2’ ceilings.
The addition consists of 2 rooms. A 12x14 bloom room, end to end with the existing one and a 8x16 “work” area that the hallway runs into.
There is no heat in the barn, other than space heaters.
I will be running 5 – 1000W lights in the bigger room and 4 1000W in the other on flip light schedules. The veg room currently has 5 4ft 8 bulb t5’s.


The rooms are almost done. Drywall is up and being taped & mudded right now.

I cannot decide on how I want to equip everything.. Cost is basically no issue for any equipment, I already have a Titan Helios 8 - 8 light controller with dual trigger cords, that i would like to use.. but beyond that i just can't make up my mind.. to many options and all have there pros and cons.

I'm an experienced grower, and love doing what i do. I've helped dozens of other growers get started, or helped them get things where they needed to be.. but i'm draggin my feet on my own "dream rooms" because of indecision and over thinking everything.

So please offer me any opinions, suggestions or whatever else is on yer mind.

First off, I want to figure out my ventilation set up before the drywall is done

What my rough idea is something along the lines of this..

During the cold season, I would like to make use of the hot air that the lights generate.
Pulling air from the hallway/work room to vent the hoods in both bloom areas and having that air exhaust into bloom rooms. Then have fans on a temp switch that, when needed will kick on and exhaust which ever room is on, into the room that is off.

The veg room, also on a temp switch, will just exhaust into the work room.
Would this scenario work if using co2?
During the hot season, I would just exhaust the flower lights outside and run AC when needed.


I have never ran sealed rooms with co2 enrichment, I’ve always just used fresh air intakes and exhausted my light separate from my rooms in the summer and then in the winter used the lights as my intake, using the lights to heat up the cold air and having the filter/exhaust set on a temp switch.

Would I be better off running each room individually? Each having their own co2 system and vent my lights separately, using “outside” air to cool the lights and exhaust them outside and just run heaters if needed?
Or maybe skip co2 all together and just run the new room how I've been running the existing?

Let me know your thoughts! All opinions / ideas are very much appreciated!

a sketch of my rooms

Hmmm that is a tricky one. I love the idea of a flip and one side heating the other.

If you want to run a sealed room (I really dig them) then I would set it up the 2 side by side flower rooms like this...

Non air cooled lights in each room and 2 nice 8" fans passing air from one room to the next (if not more). Put a co2 burner and PPM controller in ONE room.

Now, the circulation fans and co2 run 24/7. The lights on side heats the lights out side and then they flip. Depending on your climate it could work very well. Now in the summertime, you would have to run AC. Not a huge one, probably a 24k mini split with two blower units, one in each room. Now your pretty much full auto. Which is a very very nice thing

P.s. with that much space you should run more watts yo!

legallyflying said:

Hmmm that is a tricky one. I love the idea of a flip and one side heating the other.

If you want to run a sealed room (I really dig them) then I would set it up the 2 side by side flower rooms like this...

Non air cooled lights in each room and 2 nice 8" fans passing air from one room to the next (if not more). Put a co2 burner and PPM controller in ONE room.

Now, the circulation fans and co2 run 24/7. The lights on side heats the lights out side and then they flip. Depending on your climate it could work very well. Now in the summertime, you would have to run AC. Not a huge one, probably a 24k mini split with two blower units, one in each room. Now your pretty much full auto. Which is a very very nice thing

P.s. with that much space you should run more watts yo!

Click to expand...

hey legallyflying.

What's the reason for non air cooled hoods? more heat? or better light coverage?

With only running co2 in 1 room, that would be suffient for both? assuming i had great air flow?

thanks for the info

You have to think , the light on say (bloom room)
Vents into the vegg room , then out to your work area ,
Now the air temp ?? ( won't know untill it all running ) in the work area say 60deg vents into
bloom room cooling lights as well as heating the vegg room ,
Now you might need a little shop heater in there while the light are off , but you can start each room up with lights on and cmf pumping into your vegg room ,
mabe a little shop heater in your work room is enough to heat everthing while your lights are off !!

Only big suggestion I have is make sure your lights are off in the hottest part of the day !!
so your plants use the ( lights , heater ) heat in the coldest part of the night !!

Co2 , put a hose in one room , then run a splitter in to the other room ,
mid it were me I would have the vegg room vent into the bloom room so that the co2 goes into both rooms !!
So hose in both rooms , just more co2 in the bloom room because of the cmf fan imop

Thumbs for the sweet grow room !!

I say non AC hoods to generate heat. My thought is that the two rooms will have the same exact temp, humidity, and co2 levels 24/7.

In terms of co2, fuck the tanks dude. Get a tankless water heater and install it in one room. You could also keep the drum of water you need to run it in the veg room or whatever to help modulate temperatures a bit.

My thinking is that if you get a harvest out of each room now then you could invest in a nice minisplit with two fan units (one in each room) and be cool and the gang for the summer months.