Questions regarding ventillation

[RiddleMeThis]

Will have two 4x4 tents within a roughly 11' x 7' space.

I am hoping to exhaust my scrubbed air into the chimney, where the furnace exhaust exits. The problem is, the largest ducting I think I can safely attach will be 4". I will have two 8" fans worth of air to exhaust. Can I bring them to a Y, and reduce to 4" ducting and out through the chimney, or will that cause issues?

Only other option would be to exhaust into the storage room on the other side). Unfortunately that will be where I am bringing air into the room. Would I then need to supplement CO2?

Lastly, would the 2 8" fans, and a 6" (~1800cfm capable, but will likely be running around 50%) fan create enough negative pressure to pull enough air passively into the 11x7 room from inside the tents, or will I need some sort of axial fans to ensure enough fresh air?

Id imagine I wont know for sure until I try... Any tips on what to look out for/how to identify issues before they become a problem?

Just started germing seeds, so need to get this figured out ASAP :-(

 

[Speed of green]

ideally 8" ducting would be best, that 4" chimney even though it is hard-ducted is going to seriously restrict your 8" fans. That being said you still might be able to get enough airflow to cool/vent those tents. an 8" fan is way overkill for a 4x4 tent.

Supplementing co2 would be wasteful if you are exhausting it out of your tent, you would need a sealed room to use co2 effectively.

your 8" fans are going to pull plenty of air from the surrounding area as long as you are exhausting outside of the 11x7 room

its going to take some troubleshooting/tinkering to make this work correctly, thats the fun part!

for my 8" fans i like to use zip ties to secure ducting, link a few of them together and pull really tight.

 

[RiddleMeThis]

What if the 11x7 room is pulling air from the same room I'm exhausting into? It is rather large so maybe it would be ok.

Went with the 8" hyper fans rather than 6" to run them at ~50% and crank them up if need be. Gonna have 1k hid in each.

 

[noyd666]

scrubbed air would be ok, I do the same but have filtered air coming into lung area.have 4 phresh hyper 8 scrubbing into room no problem.

fans are great, less noise when you choose.

 

[Speed of green]

What if the 11x7 room is pulling air from the same room I'm exhausting into? It is rather large so maybe it would be ok.

Went with the 8" hyper fans rather than 6" to run them at ~50% and crank them up if need be. Gonna have 1k hid in each.

I think exhausting into/ pulling from the lung room would be okay, you may run into heat issues depending on the temps in lung room, this could easily be fixed down the line with a small window ac in the lung room.

I would set everything up the lung room route, run it for 24hrs and check temps.

i have several 8" fans and when they run %50 they drone really bad, much louder than when they are on %100.

 

[Speed of green]

disregard the loud fan comment, those fans are legit at lower speeds.

The ones i have that drone look like https://www.amazon.com/Hurricane-745-CFM-Inline-8-Inch/dp/B006Z1JLN0

 

[RiddleMeThis]

Yah that's why I'm going with the hypers. I'm sure down the road they'll get louder.

So the lung room has an unfinished ceiling (basement). How is the smell for you? All exhaust fans will be scrubbed with phresh filters. Smell is a bit of a concern for security issues, rather than legal, which to me is worse. While my grow may be legal, I don't want everyone knowing. I am hoping some one gel tubs with the fan lids will alleviate that concern. Any tips?

 

[noyd666]

put some panda across roof ceiling, seal it.

 

[Speed of green]

If you run the exhaust through the carbon filter you are set, no smell whatsoever.

 

[Chunkypigs]

I am hoping to exhaust my scrubbed air into the chimney, where the furnace exhaust exits. The problem is, the largest ducting I think I can safely attach will be 4". I will have two 8" fans worth of air to exhaust. Can I bring them to a Y, and reduce to 4" ducting and out through the chimney, or will that cause issues?

besides killing the occupants when the furnace kicks on and exhausts into the house because the chimney is pressurized from those fans?

 

[Can of Bliss]

Running exhaust into a chimney that is use is a bad idea. This thread has gone passed that now, but just wanted it to be said.

With a lung room, you can seal it, have it filtered, or both. Are you worried about people smelling if from inside your house or outside?

 

[Can of Bliss]

besides killing the occupants when the furnace kicks on and exhausts into the house because the chimney is pressurized from those fans?

Oh, you got there already. Apparently it takes me an hour to write a post tonight.

 

[RiddleMeThis]

Phew �� glad I asked.

Both inside and out. Lung room I don't mind as much, but would prefer to kill the smell entirely. Part of the reason I got the 8" hyperfan vs the 6".

Plan on replacing scrubbers as often as needed, and ona gel buckets if necessary.

It's been quite some time since I've ran something this large (only 2 4x4), so a bit nervous I'll miss something in my planning

 

[RiddleMeThis]

To be more clear on the set up:

2 4' x 4' x 6'7" tents, 8" hyper through 8"x24" phresh filters scrubbing tent air, and a 6" hyper exhausting sealed reflectors, as well as scrubbing the area outside the tents.

Might be overkill, might be a bad idea. This is being set up in a few phases just in case of change in plans. At the moment we have 1 4x4 setup, but no plants in the tent yet. Still finishing up the room/electrical/ventilation.