ventilation for homebox xs?

[hlep]

i'm setting up a homebox xs (2' x 2' x 4') pretty soon and i have all the parts ready except for the exhaust fan and carbon scrubber. for the light, i plan on having a 250 watt hps housed in a cooltube.

i do plan on using a carbon filter...and probably will do

carbon filter --> cooltube --> exhaust fan.

i know that carbon filters often half the cfm of inline fans. would i be alright with a 4" inline fan at 170 cfm or do i need a 6" inline at 460ish cfm?

i've also seen a "low cfm" vortex that is around 250 cfm.

how loud are these fans btw?

 

[clowntown]

Running more volume of air than recommended results in a shorter contact time with the carbon, which equates to less effective odor control. At face value, it would not be wise to run a 460cfm fan through a (for example) 300cfm filter. However other things come into play in your configuration since you will lose some velocity & volume through bends, ridges and distance in your ductwork. Exactly how much you will lose is dependent on all those variables (and more), but the 460cfm fan will always be moving less than its face value which is rated under optimal conditions, i.e., no duct, equal pressure, etc. (Mounting the fan directly onto the scrubber is a slightly bit different story.)

There are speed controllers that can vary the speed of the fan.

Now that you understand the concepts... a 4" Vortex ought to be plenty for that size & wattage of a grow to operate a scrubber as well as cool the lights.

These fans are relatively quiet compared to other types of fans available such as the squirrel cage (and sometimes axial) which is commonly used. You can certainly reduce the noise by running efficient ductwork: smooth-bore duct is quieter than a flexible "dryer hose" with ridges (you can also find semi-rigid/flexible ducts as well), as well as less bends. Other active measures such as insulated ducting, enclosing the fan in a sound-absorbing enclosure, and installing a muffler can help reduce the noise level even further.

 

[JustEnoughForMe]

clowntown,

is an inline centrifugal fan quieter than the vortex ?

 

[clowntown]

None that I am aware of; my understanding is that Vortex and Elicent makes the quietest and best balanced fans at these sizes.

 

[Goat]

Hey man,

I have an XS with a Can 2600 and an active air 180cfm centrifugal fan. I have the scrubber outside of the tent with exhaust being blown .through. the filter. I haven't had any odor problems and the fan keeps good, continuous negative pressure with only the subtle sound of rushing air. I thought the scrubber took up too much room in the cab so i just reversed it. In retrospect I should have taken the dust cover off the scrubber and placed it over the intake, but whatever.

The only cool tubes Ive seen come in 6in and are about 19-29in long. 5in too long even without ducting. If you find a smaller one I'll buy it on the spot, i want one too! As long as you maintain your canopy height and put in another fan to move air around it, you'll be alright without it. Unless you have high temps in general.

If you haven't ordered yet, check out the S size homebox 3x3x5...just a bit more room to get a scrubber and cool-tube in.

Good luck man, the XS/250 combo has been working great for me and I'm sure it'll do well for you too! - Goat!

 

[hlep]

Hey man,

I have an XS with a Can 2600 and an active air 180cfm centrifugal fan. I have the scrubber outside of the tent with exhaust being blown .through. the filter. I haven't had any odor problems and the fan keeps good, continuous negative pressure with only the subtle sound of rushing air. I thought the scrubber took up too much room in the cab so i just reversed it. In retrospect I should have taken the dust cover off the scrubber and placed it over the intake, but whatever.

The only cool tubes Ive seen come in 6in and are about 19-29in long. 5in too long even without ducting. If you find a smaller one I'll buy it on the spot, i want one too! As long as you maintain your canopy height and put in another fan to move air around it, you'll be alright without it. Unless you have high temps in general.

If you haven't ordered yet, check out the S size homebox 3x3x5...just a bit more room to get a scrubber and cool-tube in.

Good luck man, the XS/250 combo has been working great for me and I'm sure it'll do well for you too! - Goat!

thanks for the replies guys.

i've already ordered the homebox xs, but i'm still confident in my purchase. i can't really go any bigger than 2'x2' so that was why i stuck with the homebox xs.

as far as the cooltube. why won't the cooltube fit in the cab? i thought the cooltube was 19" and the cab is 23.5" in width....wouldn't that still leave 4.5" for ducting?

 

[clowntown]

It'd leave 4.5" for ducting, but how will you run it? More than likely it will require an elbow, not to mention some clearance for the air intake. Your best chance is mounting the Cool Tube diagonally.

 

[Goat]

I did some measuring and even with the smaller 19in cool tube you'll still have to sacrifice at least six more inches of headroom. Its 33in corner to corner diagonally and 19in from corner to top vent/sock so you would have to make the ducting wrap back over the cool tube and out the top sock. If you don't mind your light being off center you could make it work without a bend, but then you'll lose light efficiency.

The volume of the XS isn't all that much so a 180cfm fan is going to exchange the quite frequently - sorry, I'm horrible with math so i cant give you a number - My exhaust bends twice before it hits the scrubber though and still keeps the tent ventilated sans cool tube.

Hope this helps dude - Goat!

 

[hlep]

update!

well i ended up getting a 6" vortex with a speedster fan controller. (449 cfm) i plan on running the fan at 1/2 speed. the reason i ended up going with the 6" vs the 4" is i found out that the 6" and 4" both create the same amount of noise. i'm hoping that if i get a 6" and then only run it at 1/2 the speed i can having the least amount of fan noise. also...if i ever upgrade i can still use the 6".

i'm also going with a DIY cooltube instead of the premade cooltubes. this is because the DIY cooltube w/ the pyrex bake-a-round tubes are only 14" long vs 19".

 

[vindiesel]

i have a small HTG tent using 250CMH. i was gonna go with a vortex but i wanted as close to silent as possible. i use 3 4" 120cfm axial fans. works fine. quiet. also keep an oscillating fan going. i could not use axials with more light (heat).