My ventilation system! HELP!

[Danny Weedman]

Hello all ive been reading on rollitup for a while now but never posted anything. My grow room is almost setup the only thing im stressing about is the ventilation! so i was thinking i have a small space for my plants ill have about 3 plants maximum. Its not very wide, but pretty lengthy grow space. I would get a picture but my camera wont work. I was thinking of a 150 cfm intake fan and a 190 cfm exhaust fan with a carbon filter. Will the exhaust cfm destroy my plats because its higher then the intake? I have the intake and exhaust fan as well as a small hawaiian breeze at the bottom circulating. Please help!
Keep em lit

 

[hotrodharley]

Hello all ive been reading on rollitup for a while now but never posted anything. My grow room is almost setup the only thing im stressing about is the ventilation! so i was thinking i have a small space for my plants ill have about 3 plants maximum. Its not very wide, but pretty lengthy grow space. I would get a picture but my camera wont work. I was thinking of a 150 cfm intake fan and a 190 cfm exhaust fan with a carbon filter. Will the exhaust cfm destroy my plats because its higher then the intake? I have the intake and exhaust fan as well as a small hawaiian breeze at the bottom circulating. Please help!
Keep em lit

All else being equal, your exhaust fan will pull that extra cubic feet its moving from somewhere if full speed. Buy a cheap light dimmer switch to control the speed and run it slightly less than full tilt. Ventilation is a key element in good growing and you're smart to pay attention to it before starting a grow.

 

[Danny Weedman]

All else being equal, your exhaust fan will pull that extra cubic feet its moving from somewhere if full speed. Buy a cheap light dimmer switch to control the speed and run it slightly less than full tilt. Ventilation is a key element in good growing and you're smart to pay attention to it before starting a grow.

So if i have a 190 cfm exhaust fan i should get a 190 cfm intake fan? Btw is it possible that this is way too much cfm for my small space? Does it matter or am i fine?

 

[The Count]

In such a small space why do you need an intake fan? Put a hole at the bottom of your room and the exhaust at the top and the simple pulling of the exhaust with naturally pull in fresh air. I ran 2-6'' vortex in my 10x12 room and just had one of those screen vents at the bottom of my room and I got plenty of circulation(with a couple pedastal fans as well)

 

[Danny Weedman]

what do you mean by screen vents? and i dont want the smell you know leaking out in the open so what do you suggest? because my exhaust is a carbon filter

 

[The Count]

so youre pulling through the carbon filter and out the exhaust correct? As long as you have air flow coming in from the bottom and out through the top you wont have any smell escaping. The problem is when your exhaust fan is off and its stagnant inside...then you will get some escape smell. I had my exhaust fans on 100% when lights were on... then on for an hour off for and hour and continued that rotation during dark cycle. The vent im talking about is like these...

http://www.homedepot.com/h_d1/N-5yc1vZar6b/h_d2/Navigation?catalogId=10053&langId=-1&storeId=10051&cm_sp=d26-_-plumbing-_-know_how-_-buying_guide-_-Venting

 

[Danny Weedman]

So i should just cut a box hole shaped and then stick a vent in there? and if you couldnt tell this is my first grow...but im afraid of ANY smell leaking at ANY time...so do you suggest just getting an intake fan so im safe?

 

[Danny Weedman]

or get a vent that can close to seal off smell? would that work?

 

[hotrodharley]

So if i have a 190 cfm exhaust fan i should get a 190 cfm intake fan? Btw is it possible that this is way too much cfm for my small space? Does it matter or am i fine?

If you're after simple plant-healthy atmospheric air there is no such thing as too much. Whatever isn't harming the plants like blowing the hell out of them is great. One benefit, a minor one and for plant lovers/eaters/smokers, related to global warming is increased CO2 in regular atmospheric air. The more air you exchange the more CO2 you bring in. This does not increase the PPM of CO2 in samples but simply increases the volume of air containing those PPM for the plant to use. Confusing?

If using a controlled CO2 system this would not be good however. This does not address any filtration at all, simply air supply/exchange.

 

[The Count]

I'm just gonna go out on a limb and say unless you have a closed grow you'll always have some smell. Its gonna be hard to grow some stanky stank without it escaping. An intake fan will help cool your room, given the outside temp is cooler than inside and I supposed if you had it running 100% of the time it would help prevent any smell getting out. I still think no matter what youll have some sort of smell escaping.. doesnt take more than opening the door for some smell to get out.

 

[Closetgardner]

like the count said just put your exhaust on a timer and set it to come on for 1 hour off 1 hour right through lights off and u wont get a smell escaping by the time the air has built up again the fan will suck it all out again.and dont worry about over thinking smell issue on your first grow your right to worry smell will get you caught

 

[Danny Weedman]

If you're after simple plant-healthy atmospheric air there is no such thing as too much. Whatever isn't harming the plants like blowing the hell out of them is great. One benefit, a minor one and for plant lovers/eaters/smokers, related to global warming is increased CO2 in regular atmospheric air. The more air you exchange the more CO2 you bring in. This does not increase the PPM of CO2 in samples but simply increases the volume of air containing those PPM for the plant to use. Confusing?

If using a controlled CO2 system this would not be good however. This does not address any filtration at all, simply air supply/exchange.

So i could blow the hell out of them and itd be fine? thats great! i was also wondering if an exhaust fan can also work as an intake fan? Having the most trouble in the world trying to find a 190 cfm intake fan please help if you can this is all greatly appreciated. and by an exhaust fan working as an intake fan i mean a seperate exhaust fan from the actually exhuast fan.

 

[Danny Weedman]

like the count said just put your exhaust on a timer and set it to come on for 1 hour off 1 hour right through lights off and u wont get a smell escaping by the time the air has built up again the fan will suck it all out again.and dont worry about over thinking smell issue on your first grow your right to worry smell will get you caught

well the thing is...id like to run it 24/7 because if its on a 18/6 scheduele theres no way im gonna be waking up to put on a diff timer so is it a bad thing to just keep them going 24/7?

 

[The Count]

yea you definitely can not go wrong with a larger fan for exhaust... Im pretty sure you want 3-5 air exchanges per hour for your room so make sure you get a big enough one for your room. It would be easier if I could draw you a picture but a fan sucking the air out is going to draw air in from another entrance. For example stick a fan in your window blowing outside... close your door and put ur hand at the bottom of the door and youll feel air being sucked into your bedroom and eventually pushed outside. I didnt have an intake fan in my room... just the power of two 6'' vortex sucking air out pulled enough fresh air in.

 

[The Count]

Put your lights on one time and fan on another... timer runs 15$ and you can set it to turn on/off whenever you want.

 

[Closetgardner]

no lots of people of do 24/7.but u would'nt have to get up to put a diff timer on just set both timers, plug in,switch on,put them on auto and they will come on and go off for u

 

[Danny Weedman]

yeah but if i put a timer on a fan wouldnt it have to be constant hour on and off? or can i set it to a certain hour cycle where i can make it do that for only 6 hours a day?

 

[Danny Weedman]

no lots of people of do 24/7.but u would'nt have to get up to put a diff timer on just set both timers, plug in,switch on,put them on auto and they will come on and go off for u

Sorry im not sure if i read you? If i put it on auto itl turn on when it needs to? how does that make sense?

 

[Closetgardner]

yes u can set it do do that just get a 10 setting digi timer

 

[Danny Weedman]

I mine as well just have them 24/7...but can an exhaust fan server as an intake fan as well? because i cant find a 190 cfm intake fan ANYWHERE