Is two 240 CFM fans enough??

[cannabis culture]

Would two 240 CFM inline fans be enough for my new tent for intake and outtake, 1 for intake an 1 for outtake?

The tent is 4 feet x 4 feet x 7 feet. Its a lighthouse tent brand, and the fans are from Ledwholesalers

 

[robnarley1111]

I'm interested in finding out the same. I am planning on ordering that tent in a week and I'd like to know what I need to keep it cooled also. Although I was thinking of going passive for the intake, for now at least.

 

[cannabis culture]

Word.... Is their anyone that could please chime in and help us out? I know their is a math formula to figure out how much CFM's per square footage would be needed, but I can't find it anymore.

 

[cannabis culture]

Also... Would 2 of these fans be neccassary? Could I possibly use one for outtake and like leave some exhaust ports open for intake? I plan on getting 2 though, but would like to know

 

[medicalman1983]

what size light? open reflector or sealed hood? my closet is 42"x32"x80" and i use a 420cfm fan turned down to about 50% and it keep temps in range and i dont use the glass on my hood and i have passive intake

 

[cannabis culture]

1000w MH veg HPS flower, but ballast is dimmable to 75% & 50%
Open wing reflector hood.

Here is the tent: http://www.amazon.com/gp/aw/d/B0078P34A8/ref=mp_s_a_1_10?qid=1381892165&sr=8-10&pi=AC_SX110_SY165

Fans: http://www.amazon.com/gp/aw/d/B003YFADW8/ref=pd_aw_sims_1?pi=SL500_SS115

 

[medicalman1983]

the fan would probally work if you run your light at 50% but idk if it would work that good a the full 100%. probably better off buying a better fan from htgsupply.com, ebay or amazon

 

[Turbanator]

depend on what light ur using, i run a 5" rvk on a aiorcooled hood wuth a 600 in to the filter with a 400 in a reflector and have no heat problems

 

[robnarley1111]

Word.... Is their anyone that could please chime in and help us out? I know their is a math formula to figure out how much CFM's per square footage would be needed, but I can't find it anymore.

I hear that if you multiply the dimensions, that will give you the CFM's needed.

So 4 x 4 = 16
16 x 7 = 112 Cubic Feet

So maybe we'd need at least 112 CFM to replace the air in that size tent/cab every minute...I'd imagine? Maybe even double, or 200+ CFM with a carbon filter attached (depending on the light/heat..probably more).

 

[skunkd0c]

I hear that if you multiply the dimensions, that will give you the CFM's needed.

So 4 x 4 = 16
16 x 7 = 112 Cubic Feet

So maybe we'd need at least 112 CFM to replace the air in that size tent/cab every minute...I'd imagine? Maybe even double, or 200+ CFM with a carbon filter attached (depending on the light/heat..probably more).

this area calculation was supposed to give the fan size that was needed to remove all the air in the space
in 10-15 mins or like at least 4-5 air changes per hour, this is grow book talk

this is to bring fresh air into the space not so much for removing heat from the light

so from the old grow book formula you want a fan that can remove 112 cubic feet in 15 mins or less
it works out that most 6 and 8 inch fans can remove the air much quicker than whats recommended
with air changes more likely every 5 mins or less, the faster the better

peace

 

[strain horder]

lets do the math.. You want to be able to extract all air from room in roughly 1 minute... So 4x4x7= 112 cubic feet. Your fan is 240 CFM so you should be fine. Now remember, if you have any bends in your ducting, you lose CFM's... So try and have as few bends in it as possible..

 

[cannabis culture]

Cool thanks for all the help, I'm 100% confident these fan will be cool for my tent and exchange the air great. As far as if I get high temps I guess I'll just have to wait till everything is set up and running and take it from their; maybe get another inline., open extra ports for some passive intakes. Or somethin I'll also have a circulation fan too.

 

[AimAim]

Don't want to be negative but I had 2 of those fry in very short order, one within hours. Amazon replaced both and I switched to this and it was worth price difference.

http://www.amazon.com/gp/product/B002JQ14F8/ref=wms_ohs_product?ie=UTF8&psc=1

 

[fir3dragon]

Don't want to be negative but I had 2 of those fry in very short order, one within hours. Amazon replaced both and I switched to this and it was worth price difference.

http://www.amazon.com/gp/product/B002JQ14F8/ref=wms_ohs_product?ie=UTF8&psc=1

i got the same thing. With this, you can use passive intake