how much vent for 2.3 square meter (5x5 foot) grow

[PainMan]

Planning a grow space and I need better info on ventilation gear. The grow room contains two spaces (2.3 square meters, aka 5x5 foot). I am not using zip up grow tents, just to areas enclosed by panda.  The entire volume of the room where they are (8' high, and 11' x 8') comes to a CFM of 234.67. I have no idea where and what to get to move that much air.
 

Edited December 24, 2019 by PainMan

[PainMan]

 The entire volume of the room where they are (8' high, and 11' x 8') comes to a CFM of 234.67. I have no idea where and what to get to move that much air.

 

I re-measured our ceilings & they are 10 feet high.  I think the room is actually 12'x12'. That means all the measurements posted in my title were incorrect. Inside of the grow room are two panda plastic spaces that are 5wx8lx7h (in feet). I expect that I will need to treat each one a bit like a grow tent of it's own to get good ventilation.

 

That means I should aim for a whole room CFM of 500. But...

 

I've been reading and learning and looking at fans online. Tutorials say to multiply the necessary CFM for the room by 2 or 3 depending on how long your ducts will be. Also I would want an intake and exhaust in each growing area. I'm not sure out that works against CFM. Running on both intake and exhaust means that the individual fans do not work as hard. I am uncertain how this translates to CMF requirements.

 

If you have solid knowledge for ventilation and filtration I would like to hear for you.

Edited December 24, 2019 by PainMan

[Porky 1982]

Im assuming by CFM you mean cubic feet per minute.

My can fan 8 inch according to the specs can move 1293 cubic meters of air an hour or 21.5 a minute so roughly 65 cubic feet a minute.

My space is roughly the same size maybe a bit bigger.

I run my fan at about 40% power and its more than adequate.

Not sure about why you think you need that much air movement per minute.

 

Posted from the OZ Stoners mobile app

[Serrated edge]

[quote name="PainMan"Inside of the grow room are two panda plastic spaces that are 5wx8lx7h (in feet). I expect that I will need to treat each one a bit like a grow tent of it's own to get good ventilation.

 

YES

 

 

 

That means I should aim for a whole room CFM of 500

NO

[PainMan]

my

 

Im assuming by CFM you mean cubic feet per minute.
My can fan 8 inch according to the specs can move 1293 cubic meters of air an hour or 21.5 a minute so roughly 65 cubic feet a minute.
My space is roughly the same size maybe a bit bigger.
I run my fan at about 40% power and its more than adequate.
Not sure about why you think you need that much air movement per minute.

Posted from the OZ Stoners mobile app

 estimates on the amount of air I need to move are based on ventilation calculators and FAQs. 

http://cannaversity.com/calculators/lighting.php

If I look at it as two separate grow spaces (each on 5x5x7, or 1.524m x 1.524m x 2.133600m) the calculator there says I need 160.4 Cubic Feet per Minute (4.54202221255476 cubic meters per min, or 4542 liters per min)

[Porky 1982]

There ya go the fan i mentioned can do 4 times what you need.

 

Posted from the OZ Stoners mobile app

[PainMan]

thanks to everyone for the information. I never grew enough in the old days to require this sort of setup (big isolated country houses do not require the same ventilation efforts for small grows), but this time I have to do a relatively large continual production grow for two very sick family members. Most likely I will use 630 watts of CMH in each of two 1.524m x 1.524 m spaces (one space veg, one space flower, scrogged in individual sips, organic/probiotic grow).

[PainMan]

the online c

 

Just to add a different approach to sizing fans.

100 litres per second for every 1000w of light. Roughly, 6m of ducting will 1/2 the flow as will a carbon filter, so factor them in.

I used an online calculator that figured in the loss of air flow from the length of the ducting. I couldn't find info on what the carbon filter does to the rate of flow.

[PainMan]

which fan is that? name/model or link?
 

Edited January 6, 2020 by PainMan