My fan

RAD

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Hey guys,

First of all im a compete noob so if anything sound wrong im sorry.

I just started my grow room and it measures 53" x 54" x 95"H, I didnt have a lot of money to start up with so i settled for 4" (100mm) bathroom fans for my air intake and out take cuz the room is very small.

Personaly i think they move plenty of air but somone is telling me i need at least 250mm fans for the job, Is this true?

my cuttings aint here yet but i dont wanna put them in there if the fans aint gonna be good enough!

Thanks for the help everyone!

RAD
 

learnin to gro

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size of fan does not matter its the CFMs you have a 160 cubic feet in that room im not sure what the formula is but i think you want to replace the air in there once every 5 minutes...correct me if im wrong pros... also the main concern with fans is usually they cant move enough air to keep it cool.
 

RAD

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the fan is apparently 20 CFMs is that enough? plus was was hoping to attach a carbon coal filter i guess thats out of the question.

Thanks for the reply bud!

RAD
 

Mutt

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Here is a neat little greenhouse CFM calculator. If ya think about it all a grow room is...is an indoor greenhouse. Same air replacment "should" be the same. but of course the bigger the HID the faster you have to replce air. But this calc. does give ya a rough estimate. If in doubt bump it up.
http://www.littlegreenhouse.com/fan-calc.shtml

It also does the intake holes needed.
 

RAD

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thanks mutt i really apriciate the help!!
 

RAD

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it is sufficent, How much exraction do you loose to a coal filter?

Thanks For all the replys.

RAD
 

Mutt

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With a homemade carbon filter you're gonna need a pretty good blower or squirrel cage fan. because of the resistance caused by the carbon, you'd prolly need a couple hundred CFM's. I'd go to Lowes and pick up an inline exhaust fan. think a 210 +/- CFM inline is about 30-40 bucks. They be noisy but cheap.
You'll have to put a plug on it.
 

RAD

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i worked out my fan was approx 150 CFM and accourdin to the caculator i needed 124 CFM for my room, Do you think i have enough to put a filter on if i buy a good one?

Thanks Again mutt i really apriciate all the help.

P.S i dont think the have lowes im my country so ill have to find an alternative.

RAD
 

learnin to gro

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the inline fan hes talking about is used for boosting airflow in forced hot air heating systems an electrical or plumbing supply store should have em i bought 2 for 65$ for a room 30% smaller plus there 6 inch which is what vented hoods are.. id definately get more instead of less my attic stinks badly with no filter and im only 1 month into vegg. and its pretty warm in the room
 

RAD

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so.. can i do this, attach the carbon coal filerter to the new inline fan then attach the inline fan to my exhast fan with ducting. Will this work? or should i replace the old fan with a inline fan?

Sorry i really am a noob with all this and your all a massive help!
 

learnin to gro

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actually if you get the inline fan im talking about it doesnt actually put ouit say 220cfms but when boosted will supply that much so it would be optimal to attach with your current fan you just need a 6inch to 4inch reducer for the ducting on the current exhaust which i assume isnt a 6 inch
 

Mutt

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You need to replace the old fan. When pushing through a homeade scruber. You have to play with the CFM ratings. Thats why the store set-ups are so expensive. They have the size of the carbon filter, the right intake and exhaust fans, everything worked out for you.

The hard part is sizing the exhaust inline to the carbon scrubber. Once that is worked out the intake is easy to figure out. The main variable is the size of the filter and the amount of carbon that the air has to be pushed through.

I would say double what you need if you need CFM to push it through the carbon. If your room needs 135 CFM's do 250 CFM's or so. and the right size intake per the calculator. This is off the top of my head though. Let some others chime in. I spent 2 weeks figuring mine out. and don't care to do it again. LOL Gave me several headaches.

I would do some googling and decide what you want to do.
 

Mutt

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learnin to gro said:
hey mutt not trying to step on toes just im a carpenter and its kinda up my alley
No worries man, I'm in the same business. ;) I just hate calculating air flow. Its a PITA when you throw carbon and static pressure into the mix. If you got it worked out I'll let you guys take it from here.
 

RAD

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right ok thanks guys i really appriaiate all the help you guys are awsome!

Ill play about with it and find out what works best and let you know what i did so it might help other people having the same problem.

Peace,

RAD
 

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