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Ventilation help!

TheGrowerOfDank

New Member
First timer here! I need help with a couple things for my ventilation system. The tent I’m getting needs an extractor fan that’s 130cfm or about 220 m3/h, whilst im in the vegetative stage will I need to have my extractor and intake fan on a lower cfm?
 
Last edited:

Pbass

Well-Known Member
Hiya @TheGrowerOfDank I'm pretty new and honestly I don't have anything but a few fans in my rooms...I tend to troll the unanswered questions, when they go too long sometimes I try and spark em up so to speak. The reason I decided to pop in here specifically is because the thought popped into my bean after reading your question that depending on your light source, you should not see significant differences in temperature between veg and flower. Most of us tend to run the same watts (full bore) all the way through around here. Therefore, it stands to reason you shouldn't need to adjust the amount of air you are moving either. Even smell shouldn't change, people say veg doesn't smell much but you just brush up against a plant and BAM it farts out a whaft of weed stink like you wouldn't believe! Anyway, figured I'd toss it in here! CHeers and gl to your grow! :yahoo:
 

shottafire

Member of the Month: Sept 2013 - Nug of the Month: July 2014, April 2020
First timer here! I need help with a couple things for my ventilation system. The tent I’m getting needs an extractor fan that’s 130cfm or about 220 m3/h, whilst im in the vegetative stage will I need to have my extractor and intake fan on a lower cfm?
Depending on where your located and what the environment is like I would over compensate on the fan and get a speed controller. Will you be attaching your fan to ducting and a carbon filter? If so you need to upsize the fan accordingly. If your using a carbon filter you don’t want to pull air too fast through it or it won’t scrub the air and will leak smell out of your room. Lots of variables at play. If you have any questions feel free to hit me up.
 

TheGrowerOfDank

New Member
Depending on where your located and what the environment is like I would over compensate on the fan and get a speed controller. Will you be attaching your fan to ducting and a carbon filter? If so you need to upsize the fan accordingly. If your using a carbon filter you don’t want to pull air too fast through it or it won’t scrub the air and will leak smell out of your room. Lots of variables at play. If you have any questions feel free to hit me up.
Yea I’ve added 40% on to the cfm of my extractor fan (which takes the required cfm to 130) to compensate for my carbon filter which will have ducting too. Can I buy a speed controller for the fan separately or will I have to buy a fan that comes with one? The fan I plan on getting is 160 cfm, do you think that this would suck air out too quickly for the carbon filter?
 

Stunned

Well-Known Member
You need fresh air coming into your tent, more specifically CO2.
Your extraction fan is pushing hot stale air out of your tent, you need a fresh supply of new air coming in.
I have the same inline fans on my intake and exhaust
Good air in, bad air out. I like to find an equilibrium where I'm pulling in, about the same as I'm pushing out.
AC Infinity Cloudline fans work really well for this and are speed adjustable.
 

TheGrowerOfDank

New Member
Oh yea another question guys. Do I need the ducting for my inline fan to be getting air from an open window or can I just get the air from the other side of the room away from the tent. Only thinking of not getting bit from the window as loads of ducting hanging out my window looks a tad bait :nervous-guy:
 

shottafire

Member of the Month: Sept 2013 - Nug of the Month: July 2014, April 2020
Oh yea another question guys. Do I need the ducting for my inline fan to be getting air from an open window or can I just get the air from the other side of the room away from the tent. Only thinking of not getting bit from the window as loads of ducting hanging out my window looks a tad bait :nervous-guy:
As long as you have enough air going out the tent will passively bring air into your grow environment. But you do need a window for a source of fresh co2 and cooler air. Give details about your climate if you can and is this in your house that you live in? There’s many ways to grow this plant, some ways better than others. Just a matter of finding what works in your situation.
 

TheGrowerOfDank

New Member
Cheers for your help mate! My tent is going to be situated next to the window where my extractor ducting is going to go in my bedroom, I live in the uk outside humidity ranges from 40-100% throughout the day. At the min it’s usually at least above 14 degrees outside. Also will I need to have my fans at a different cfm during veg and flower for the temp and humidity?
 

shottafire

Member of the Month: Sept 2013 - Nug of the Month: July 2014, April 2020
Cheers for your help mate! My tent is going to be situated next to the window where my extractor ducting is going to go in my bedroom, I live in the uk outside humidity ranges from 40-100% throughout the day. At the min it’s usually at least above 14 degrees outside. Also will I need to have my fans at a different cfm during veg and flower for the temp and humidity?
I personally never adjust my exhaust fans I run them full tilt start to finish. This keeps things fairly consistent for me. But don’t be afraid to adjust yours as you see fit in your space. It’s about finding what works for you in your space. Just remember there’s always gonna be different ways to do things and keeping an open minded approach is always better than just say taking my advice and only doing that. Be flexible and remain teachable you will never know everything.
 

shottafire

Member of the Month: Sept 2013 - Nug of the Month: July 2014, April 2020
That’s really helpful mate thanks!! Gonna do the same I think and run them on full throughout as long as humidity and temp don’t drop too much
Yeah bro no worries. I think you should do just fine. If you ever have any questions feel free to hit me up.
One Love
 
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