DeuceyNugg
Member
Im just courious , how do i know how big to go on fan/ filter? and if they should push or pull? cool tube light is what im using if that helps, thanks
Carbon Filter/ Fan setup
- Thread starter DeuceyNugg
- Start date
420God
Well-Known Member
It's more efficient to pull air and the fan should be big enough to move the volume of air in your grow area 2-3 times a minute.
Example: I have a 3x3x6.5' tent = 58.5 cuft, I run a 190cfm fan that is capable of exchanging the air 3.24 times per minute.
rockbud
Active Member
exactly!!u should rep this guy!i have a bigger room..so i go w a 500cfm!
WeeGogs
Active Member
this is wrong you only need to exchange the air 1/3 to 1/2 in the grow area per minute.
so i will do it in ft and then meters as i live in the uk.
3 x 3 x 6.5ft = 58.5 sq ft.
58.5 sq ft x 60 minutes = 3510 sq ft divided by three which is one third = 1170 sq ft hr fan minimum go for a large bore fan to keep the noise levels down.
1 metre x 1metre x 2 metres = 2 cubic metres x 60 minutes = 120 cubic metres divided by three = 40 c m hr fan so a 4 inch fan 100 cmh is more than perfect.
Oldreefer
Well-Known Member
I'm running a 4" vortex fan, 200cfm, controlled by a speed control....pulls air from carbon filter inside tent...thru cool tube....Have the same size fan/sp cont. as fresh air supply, drawing fresh air from crawl space..........3x3x6.5 tent....fans typically run 10-50% to maintain temps......according to ambient outside temps....been a good setup for me for over a year now...definitely improved my grows to have this type of control over growing environment....
420God
Well-Known Member
If I were to go with your method I would cook my plants.
WeeGogs
Active Member
where are you venting your fresh air from, "your oven"If I were to go with your method I would cook my plants.
if you exchange air in a grow room from outside 3 times per minute at 60 degrees outside temperature your grow space will be just above 60 degrees.
stop telling people a load of rubbish.
exchange your air 1 third on a cold day and 1 half on a warm day.
and always vent from outside on the shaded side of your home.
WeeGogs
Active Member
so you say :
my grow room is 3 metres by 3 metres by 2 metres = 18 cubic metres x 60 minutes = 1070 cfm and remember we have to change the air three times in an hour so times this by three = 3510
so i need a fan 3510 cfm for a grow room that is 10 feet x 10 feet x 6 feet.
do you know what, you can suck on your own fucking "%$^ cos you are talking absolute $%£).
my 2 fans are actually an 8" 1050 cfm and works perfectly.
indoor gardens are not a guessing game they are a SCIENCE in their own right.
Livetowin
Active Member
smoke a bowl and chill
jondamon
Well-Known Member
im really sorry but i disagree with your advice.
Air should be exchanged once per minute up to a max of 3 times per minute.. Anything above this amount then something needs to change i.e. aircooled hoods.
If you are in the UK then i suggest you pick up some URBAN GARDEN MAGAZINES especially the one about grow room design and build. In here it explains how air exchange should be created, via Exhausts and powered/passive intakes along with adding 20% to your rooms cubic dimensions for the increased resistance a filter places on a fan etc.
J
rockbud
Active Member
i agree with this..this is wat i do...works great!
WeeGogs
Active Member
i think you better get six grow rooms like i have, i dont smoke cannabis i do it for profit.
read and learn :
http://www.aquaculture-hydroponics.co.uk/admin/web-inf/uploads/documents/ventil-bound.pdf
i use 1015 cmh 8" inline duct fans
my rooms run at 20-60 changes per minute today 1 room is running at 20, and i checked the outside temp was 18c (64f) my room was 24c (75f). 4 x 600w sealed but not vented lights in a 12 metre cubed room, the room is 100 percent sealed. running at very slight positive pressure. when i run them at negative the pressure it rips the plastic from the walls.
i vent from a sealed window box with the window slightly open this causes a seething suction of air which cools it as it enters the room, a bit like sucking in through your teeth, the air will feel cold in your mouth and lungs, when it enters the groow room it is freezing so i have to split it in to opposite corners.
the only problem is if i stay in the room too long i get headaches from the positive pressure. but it actually leans that pressure on to the exhaust fan once it gets a little high. when you close the door from the inside you can hear the noise change in the exhaust fan as the extra air pressure exerts on to it.
jondamon
Well-Known Member
so now its not 1/2 or a 1/3 its between 20 and 60 times a minute?
Whatever dude with your my d@cks bigger than yours attitude.
Believe what you want, your resource is a shop mine is a publication .
http://urbangardenmagazine.com/2010/07/planning-your-grow/
Half way down it talks about oversized fans.
J
pazuzu420
Well-Known Member
Yet agian people not giving enough information, like geographical location. If I were to draw air in from outside my plants would be dead within 20 minutes as the ambient air temp in the summer is over 100 daily. So it is not always benificial to draw in outside air, although this is the best way to give plants a natural amount of Co2. Hence, when using climate controlled conditions the introduction of artifical Co2.
This thread has pretty much left me confused as I'm spending what is (for me) a crap load of money to set up a modest growroom. Jorge Cervantes recommends once every five minutes as a minimum. Please don't mistake me as a Cervantes fanboy or even stating that he's right.
I would appreciate it if Weecogs would check his posts and adjust for consistency.
My location would also cause some issues if I were to use outside air. I live in the southeastern united states and with temps in the high 90's and humidity up there as well in the summer time my plants and I would be miserable bringing that air inside. I am a little worried that my future plants might end up a bit co2 starved.
I would appreciate it if Weecogs would check his posts and adjust for consistency.
My location would also cause some issues if I were to use outside air. I live in the southeastern united states and with temps in the high 90's and humidity up there as well in the summer time my plants and I would be miserable bringing that air inside. I am a little worried that my future plants might end up a bit co2 starved.
Xcon
Active Member
In summer conditions, I use an a/c on my closet with a vent fan on a timer to exchange the air every 1½ hrs for co2. This is because I bought a cheap underpowered vent fan that won't keep my closet under 90f (ambient temps 70f, 400w lamp, 70 cu ft, air exchange once per minute). IMO, 3x per minute would be perfect under my circumstances. Hope this helps...
WeeGogs
Active Member
jorge cervantes is correct once every 5 minutes is 1/3 of 1 hour.
20 times per hour not 180 times per hour which is three times a minute.
WeeGogs
Active Member
so i put minute instead of hour LA DI FUCKING LA it is 20 times an hour which is once every 5 minutes hey jorge cervantes the people on this site call you a liar. which is 1/3 every hour.
if your grow room is too hot at this rate you may need to use a portable air conditioner and let the warm/hot inlet air go directly in to the inlet vent of the a.c. to cool the warm air before it enters the grow space.
if i was to run a fan at 3 times a minute the neighbours would hear the fan screaming its head off from 100 yards down the road.
12 cubic metres x 3 times a minute = 36 cubic metres a minute, x 60 minutes = 1800 cubic metres an hour, a fan that runs at 1800 cmh would be a fucking jet engine.