Hi folks this is my first grow room. I cant figure out whats best in term of ventilation for making
negative pressure in my flowering room. I need someone to give me some advice.
My room is sealed, its 4.5 by 4.5 foot, with 5.5 foot high.
I bought a 245 cfm fan and a 50 cfm fan the lady at the indoor store suggested according to
my room mesurements.(Ones 5 times bigger) The biggest being the intake has she said it should be.
..(here is what stucks me,...) On internet i found many people saying that the air
intake should be 5 times bigger than the outtake, but only if the intake is passive..
( no fan..just a hole.)... and this should build the wanted'' negative pressure''.
Q; How true is that? And what about If i want my intake active? Does it still needs to be 5 times
bigger than exhaust or will that demolishe negative air pression? Whats the gauge? How to mesure?
Im running a 400w, my 50 cfm fan is connected to the flexi foil that conduct to my homemade
charcoil filter wich makes a few turn here and there and is about 30 foot long leading outside.
Ive tested my exhaust and its working,air fairly goes trough even dough my filter and flexi tube
lenght causes a diminution of air flowing out.( but im aint flowering or using the room yet so i have
no clue about the smell.. therefore dont know how good it works.
NOw, since my intake wont be passive, but active ( i already bought the fan and an active intake sounds best for it
will keep airflow in my room;...Q: Would it be a good idea to switch fans, and use my
245 cfm as exhaust, and put the 50 cfm as intake, since i have another intake ( wich is at the same
time the outake of my vegetative room) ?
..As i mentioned already; my flowering room outake (50 cfm) is having a
little harder time pushing out that it should ,..
This second intake is a computeur 80 mm fan 0.19 A ( 30 cfm approx).
So swithching the fans would give me: flowering room; (intake #1: 50 cfm) + (intake #2: 30 cfm) = 80 cfm intake active vs.
a 245cfm outtake ...this one considerably reduce in capacity ;...(charcoal filter, 30 feet long flexi tube
in the way yadiyadiya...). Is it a big deal if the exhaust is bigger than intake afterall?
Does that make any sense anyone? what other option would be best? Keep it as it is would mean a 50 cfm exhaust
with diminished capacitiy blowing out vs. 2 full capacity active intake 30 cfm + 245 cfm = total 275 cfm intake active.
( ...im afraid too much air will be sucked in, not enough sucked out and therefore odor will leak out cracks.) What to do?
Also in my vegetative room i have this intake computeur fan (70 mm 0.40 A... approx.30 cfm or little more),
wich blow a little harder than the exhaust (80 mm 0.19 A.. 30 cfm approx or little less.)
This room is 2 by 4 foot with 5 foot high. Should i let the intake run? or shoul i take the fan out and
just leave a hole 5 time bigger ..like a passive intake? or is it good enough with both running... in and out
fairly equal?? HELP Tks
negative pressure in my flowering room. I need someone to give me some advice.
My room is sealed, its 4.5 by 4.5 foot, with 5.5 foot high.
I bought a 245 cfm fan and a 50 cfm fan the lady at the indoor store suggested according to
my room mesurements.(Ones 5 times bigger) The biggest being the intake has she said it should be.
..(here is what stucks me,...) On internet i found many people saying that the air
intake should be 5 times bigger than the outtake, but only if the intake is passive..
( no fan..just a hole.)... and this should build the wanted'' negative pressure''.
Q; How true is that? And what about If i want my intake active? Does it still needs to be 5 times
bigger than exhaust or will that demolishe negative air pression? Whats the gauge? How to mesure?
Im running a 400w, my 50 cfm fan is connected to the flexi foil that conduct to my homemade
charcoil filter wich makes a few turn here and there and is about 30 foot long leading outside.
Ive tested my exhaust and its working,air fairly goes trough even dough my filter and flexi tube
lenght causes a diminution of air flowing out.( but im aint flowering or using the room yet so i have
no clue about the smell.. therefore dont know how good it works.
NOw, since my intake wont be passive, but active ( i already bought the fan and an active intake sounds best for it
will keep airflow in my room;...Q: Would it be a good idea to switch fans, and use my
245 cfm as exhaust, and put the 50 cfm as intake, since i have another intake ( wich is at the same
time the outake of my vegetative room) ?
..As i mentioned already; my flowering room outake (50 cfm) is having a
little harder time pushing out that it should ,..
This second intake is a computeur 80 mm fan 0.19 A ( 30 cfm approx).
So swithching the fans would give me: flowering room; (intake #1: 50 cfm) + (intake #2: 30 cfm) = 80 cfm intake active vs.
a 245cfm outtake ...this one considerably reduce in capacity ;...(charcoal filter, 30 feet long flexi tube
in the way yadiyadiya...). Is it a big deal if the exhaust is bigger than intake afterall?
Does that make any sense anyone? what other option would be best? Keep it as it is would mean a 50 cfm exhaust
with diminished capacitiy blowing out vs. 2 full capacity active intake 30 cfm + 245 cfm = total 275 cfm intake active.
( ...im afraid too much air will be sucked in, not enough sucked out and therefore odor will leak out cracks.) What to do?
Also in my vegetative room i have this intake computeur fan (70 mm 0.40 A... approx.30 cfm or little more),
wich blow a little harder than the exhaust (80 mm 0.19 A.. 30 cfm approx or little less.)
This room is 2 by 4 foot with 5 foot high. Should i let the intake run? or shoul i take the fan out and
just leave a hole 5 time bigger ..like a passive intake? or is it good enough with both running... in and out
fairly equal?? HELP Tks
