haze010
Well-Known Member
My rule of thumb is just roughly double your cubic feet and ive never had to turn fan above half for smell, only for humidity. So like a 4x4 tent a 400cfm fan is more than good enough.
Equipment
- Thread starter KillaCarta
- Start date
Renfro
Well-Known Member
The carbon filters will have a rating for single pass and multipass CFM.
Also pull too much air and the tent implodes lol. They make high CFM kits (extra horizontal poles) that will help prevent the tent sides from sucking inwards.
haze010
Well-Known Member
Yup thats what i do with mine, except when humidity is high is around 50% for a 4x4 with a 400cfm fan.
https://www.amazon.ca/VIVOSUN-Speed-Controller-Inline-Duct/dp/B07FSGNR4F/ref=asc_df_B07FSGNR4F/?tag=googleshopc0c-20&linkCode=df0&hvadid=292954337233&hvpos=&hvnetw=g&hvrand=10498785156687963487&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9000083&hvtargid=pla-531412227753&psc=1
all i use for dimmer, does the job.
KillaCarta
Well-Known Member
Thanks brutha I understand now. I’m only growing one plant for the winter. What kind do you think I should use I’ll be shooting the air into my room.
Renfro
Well-Known Member
When I was putting up my 2x4 breeding tent I picked up a 10 inch vortex that was being sold cheaper than their 4 incher. Couldn't pass on that deal. I run it at like 40 volts on the variac, can't hear it, and it pulls plenty of air and tries to implode the tent (used 2 high CFM kits) lol.
Renfro
Well-Known Member
This is recirculation and will cause the temperature to climb unless you air condition the room the tent is in (lung room).
HydroKid239
Well-Known Member
lol funny u say that because my 2x4 has a lot of negative pressure and the walls are sucked in. It's sealed up pretty nice. I let it be tho. It builds confidence that I am keeping the tent from getting too humid during the day. I hover between 40-50%rh. I'm on day 45 of flower. Temps with lights on are between 74-80F and around 68F when they are off.
haze010
Well-Known Member
sometimes the walls sucked in too much can be from not having enough intake too, a common mistake is to seal it up for light leaks but not leave any airflow. I always leave both lower window vents open and built little light trap boxes from cardboard.
Renfro
Well-Known Member
Ideally a passive intake would have 2.5x the area of the active exhaust. So if you have a 6 inch round exhaust (28.26 sqin) you would want a passive intake area of 70.65 sqin.
HydroKid239
Well-Known Member
I keep a small section of one of the screens open on the bottom but I still get suction. I'm going to open up the one behind the tent all the way once they wake up. When lights are on I usually keep the top of the tent open to help heat get out. and to have more than one entry for clean air to get in the tent.
KillaCarta
Well-Known Member
Room will be room temp around 22-24C I could open my window tho to cool the room off. Only thing is it gets down to -40 some days here in winter lol. Are they loud?