Tutorial Ventilation 101

[Zarezhu]

Umm,with that kind of lighting you're going to need sir conditioning.

I will only use the air conditioner during the plants night cycle. The Exhaust fan will be turned off during this time, and the AC will keep the room at 65-70 during the heat of the day, when all the plants are sleeping.

Running the air conditioner while the exhaust fan is running would be very inefficient, as the room is constantly dumping the air outside.

According to the first page of this thread,
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CFM = 3.16*Watts/deltaT
where deltaT = 10 *F

Intake Area = 2 x Exhaust Area"

If this is true: CFM = 3.16*4000/10 = 1264.

However, since my fan is 1050 cfm, it would be slightly more than a 10 degree increase. This still sounds very practical,seems like it would keep it from 65 to 75/77/78. With 5000w, I would need a 1500 cfm fan.

Am I out of my mind for thinking this?


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[Jnugg]

You'll need to account for all pressure losses from long lengths of ducting,bends in the duct run,adding any carbon filter,inline filter,etc.

 

[Zarezhu]

@jnugg - luckily, there's very minimal pressure loss. The two passive air intakes are just screens, and the exhaust fan is mounted into the wall, with just enough feet of ducting to make it twist downwards on the outside, keeping the light from entering the room come day time.

If heat becomes an issue, the hoods will be ducted as well (closed loop)

also, dont need a carbon filter where im at

 

[Psuper]

Anyone reading this ever need to seal your reflective hood?
I've read to use silver tape......any experience would be greatly appreciated.

 

[echo1031]

Looking for some advice here before I go out and try a 6" fan or buy a portable ac unit. I have tried running glass and no glass on the reflector and just cant keep my temps low. It runs around 90* and the ambient temp are 75-76*. Im just using passive intakes on the bottom of the tent.

 

[Granger2]

Anyone reading this ever need to seal your reflective hood?
I've read to use silver tape......any experience would be greatly appreciated.

I use closed cell foam weather stripping w/1 side gummed. Air tight.
http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
Stick gummed side around edge of hood. Put glass on with 10-12 standard clips from school supplies.
http://www.officedepot.com/a/products/808857/OIC-Binder-Clips-Small-34-Black/
Good luck. -granger

 

[canna34209]

thanks for info!

 

[mliokv48]

So room 12x12x8 running 4 6\750flex how big ventilation do you need? I live in NorCal 4.5k elevation in mountains by Susanville.

 

[jomills1]

Never had the chance to say thanks for this because of having no account, but thanks. Has helped me in the past.

 

[beta]

.

 

[mangroef]

Very informative topic!
One thing that I can't understand, is why more than 1 air change per minute considered to be stress for plant? In outdoors it is equivalent for only 1 meter per second, and this is weary low wind, olmost a still?
More of that, many growers even place a fan inside, for more air movement in grow room.
Where is truth?

 

[weedlover_89]

Room:10x10x10

Lights:6x600w (3600w) vertical bare buls

Exhaust: 2200 CFM (without calculating carbon filters and ducts, ducts will be straight, with a length of 10 feet each)

Active intake:1100 CFM

Intake temps:60-68F

Think i will be ok maintaining temps at 75-80F? I also have a 12,000 BTU air conditioner, but obviously i don't intend on running it.

 

[weedlover_89]

Come on people, there is no one who has run a 10x10 room with active intake and exhaust?! Chime in with your experience!

 

[Snook]

"People"? WTFru, the drill Sargent? did you read any of the first few pages and try to 'grasp' it or you think 'your people' will just want to answer you?! GL.

 

[CheeseFiend]

bookmarked this great thread

 

[weedlover_89]

"People"? WTFru, the drill Sargent? did you read any of the first few pages and try to 'grasp' it or you think 'your people' will just want to answer you?! GL.

What's wrong with the word "people"? Do you prefer "dudes"? "Friends"? I don't get your problem and your attitude. I read up to page 31 if you are interested to know. EACH and EVERY POST. And i got much stuff i did not know. But each situation is special and i was asking if anyone has run a setup with similar parameters. 10X10 is not uncommon.

Thank you for the wishes. Ventilation has troubled me too much. And i have a fucking A/C i cannot use if don't do CO2 which i don't want. I am using it now with active intake and active exhaust and it keeps temps good but it has to run all the time. Money on one side, more money on the other side. I was desperate for an answer, still i don't think i offended anyone (besides you for using the word PEOPLE?)

Good luck in anything you do

 

[early4surely]

Anyone have experience with exchanging air between rooms? What are the pros/cons? Only article I was able to find on this idea is here:

http://themmjjournal.com/cultivation...looming-rooms/

Thanks for any info.
Earl

 

[weedlover_89]

A quick question for anyone who knows:

Is it ok to mix passive intake with active intake?

 

[messn'n'gommin']

Anyone have experience with exchanging air between rooms? What are the pros/cons? Only article I was able to find on this idea is here:

http://themmjjournal.com/cultivation...looming-rooms/

Thanks for any info.
Earl

The page you linked to, has either been moved or deleted.

A quick question for anyone who knows:

Is it ok to mix passive intake with active intake?

I wouldn't! There's a high probability of drawing aromatic air from your flowering chamber!

Unless you're locked in to using an active system, you might be making this a bit more complicated than is necessary.

For example: A 12" circle (your fan) has an open area of about 113 square inches. Double that for intakes (226sq.in.) and it comes out to about 15" x 15" hole. Two 8"x14-1/2" holes (14-1/2" being the typical width between wall studs) is 232 square inches.

 

[early4surely]

Seems the link got cut off. Here is the full link:

http://themmjjournal.com/cultivation/recycling-heat-between-two-blooming-rooms/

If not working, you can also access the article via this link:

https://ecannabis.com/news/recycling-heat-between-two-blooming-rooms/

Easy