Fan/ventalation advice for Closet grow

[Kinslayer17]

Greetings friends, I am new here and am setting up a closet 4x6x8. Would like to add fan and carbon filter venting to the attic, with a passive intake from the adjoining bedroom. I am growing with Leds so i am hoping temps in the summer are going to be ok, but only time will tell. I would like recommendations on fan/filter brands and sizes for this size room 4x6x8. Was looking at this combo? 6 x 14 CARBON AIR FILTER PRO COMBO 6 INCH INLINE FAN EXHAUST HV KIT SET | eBay Pro's Cons, or another brand? Price unfortunately is an issue, can't break the bank, under $250. Also was wondering about passive intake size if running 6 inch exhaust. Thanks in advance.

 

[MacEFL]

Listing removed! But I think that a 4" would suffice. I have a 4x8 tent and have a 6" turned down to 33% or so! So much quieter. And the temps stayed roughly the same. And with a 4" i would put in 2 4" intakes or 1 6".

And here is a c/p special from my local grow store. I am sure you can do well under your budget.

6" Phresh Skinny Combo (Phresh Skinny Air Filter and Hurricane Inline Fan) – $139.95

 

[Kinslayer17]

Hope I didn't violate the forum rules by posting that link....someday I will actually read the fine print before clicking I ACCEPT TERMS OF USE box lol. I was looking at a 6 inch 450cfm fan/filter combo with a 14 inch carbon filter for $139 on the Ebay. The passive vent size has me confused though, I have heard you need 1.5x the size for intake, but wouldn't you really want a slightly smaller intake size to create positive airflow and prevent smell leak/bleed. Or just make both holes 6 inch and let the ducting and filter limit the effective draw of the exhaust? Am I just over thinking the whole deal? MacEFL, did the control really help with noise that much, I have heard turning them down can actually make them louder? Thanks again.

 

[MacEFL]

I received my speed control on Friday. I am currently running the fan at 30% or so, lights on only. It is quiet and works perfectly!

 

[Guesstimator]

Hope I didn't violate the forum rules by posting that link....someday I will actually read the fine print before clicking I ACCEPT TERMS OF USE box lol. I was looking at a 6 inch 450cfm fan/filter combo with a 14 inch carbon filter for $139 on the Ebay. The passive vent size has me confused though, I have heard you need 1.5x the size for intake, but wouldn't you really want a slightly smaller intake size to create positive airflow and prevent smell leak/bleed. Or just make both holes 6 inch and let the ducting and filter limit the effective draw of the exhaust? Am I just over thinking the whole deal? MacEFL, did the control really help with noise that much, I have heard turning them down can actually make them louder? Thanks again.

Intake must always be larger. You don't want bottlenecks with fluid dynamics, which is what we are dealing with here. The air is being FORCED out by the fan, but it has to be DRAWN in and the more surface area the better for this. Same idea applies when routing the vent tubing, the less bends, and the less drastic those bends are, the more improved the airflow.

IMHO (I am still new as well), I used a 440cfm and 6" for a 2 1/2'd X 5'w X 72"h space. I would rather purchase larger and dial it back. I personally would rather reduce the speed (and duty cycle of the motor) than max out a smaller device to accomplish the same task. As a bonus, when we upgrade (when, not IF! lol) we have the proper equipment and it's a savings down the road.

Again, just my 2 cents. Make sure to research the fan controller as stories of overheating controllers and safety issues abound on the internet over the cheapies.

Good luck!