Grow tent ventilation

[westozbrownie]

Hi guys

 

I just got my tent the other day and am about to buy my fans and ducting, just wondering what you guys recommend. It's a 120x160x60 tent I plan on running two 400w lights, it's got one 8" vent in the top, two 4" vents in the back and two 6" vents on each side. I was thinking of running two centrifugal fans like this...

- A 4" induction fan at the bottom and then a 6" extraction fan on the other side of the tent up the top, my idea behind this was to get a good air flow across the plants (going from bottom to top across the tent)

 

- Or run a 6" fan induction fan at one end and a 6" extraction fan at the other end. To me this makes more sense to have the same amount of air going in and out. My only concern is that there wouldn't be good air flow going through the plants as both vents are at the top of the tent. I guess I could always poke the induction ducting down so it is inline with the plants or have a couple of small fans circulation the air around.

 

Anyway I'm keen to know what other people are using.

 

Thanks

[Razz0r]

I am going through final setup of my own tent. One thing I can say is to setup the tent where you want it and then think about it... Also are you going to use a cool hood for the lights or not? 

 

Also have a look at the tent setup guide stickied in the building section.

 

Good luck and happy growing :-)

[westozbrownie]

Yeah I'm using a light shade, not the tube style ones, the other ones

[Sir PsychoHashy]

Hey Brownie.  If your measurements are correct I have the same tent, and I can tell you now that there is no way you will get away with running 2x400w in there, unless you bung an air conditioner in there, in which case you'll have no room left for plants.  Don't know the numbers, but there is a lighting calculator in Cannaversity, and I'll bet my left nut that 800w is way over for that space.

 

You might just about get away with 600w in winter, but going on my experience with my tent, 400w should be a sensible maximum, otherwise the heat in that small a space just builds up too fast.  I only run 250w in mine, but would crank it up to 400w if I ever flower anything in it. 

 

Mines set up as follows:  2x100mm inlet ducts (location of the tent blocked off the 150mm openings, so that was my only other option) routed to the bottom of the tent, carbon filter crammed in the top, 150mm duct to a cooltube, 150mm duct to a 150mm Hyperfan, and then out the roof opening.  At 250w I only need the fan running a little over the lowest speed unless ambient temps are high, but found that I had to crank the speed right up at 400w in Autumn temperatures.  Only use this setup for seedlings so far, but if I wanted to go further with it I would put the fan and filter outside the tent so I could lift the light a bit higher.

 

Tent doesn't really have the height for growing plants to maturity, but it could be done with 2 plants max in a scrog from an extremely short veg period I suppose, or a couple of stocky auto's.

 

If you really want to run 2x400w, I would strongly recommend you get a bigger tent, and would probably recommend a bigger tent anyway as this tent is only really viable for seedlings and clones.  Best of luck

[westozbrownie]

Ok ill just go with the one 400w then, i figured it would be a struggle to fit them both in and i guess your right about the heat. I plan on having the fan and filter outside the tent to maximise the room inside. Any chance you could post up a photo of your setup? Im going the check out the tent setup guide that Razz0r mentioned. Im not %100 sure on which way around to set up the filter and fan and I don't know what a cool tube is or what it does . So with your setup you only have one fan drawing the hot air out of the tent?

[Razz0r]

check out my grow diary for pics of my setup. I have a 800mmx800mmx1.8m high and doing 600w in there I reckon is going to be too hot. Been testing the shit out of the tent and the temps in there. 

You will learn tons!!! In my diary I explain all the shit I have learned as well

 

and coz I know you will wonder about it... see the attached pic **Not Dont By Me!!**

Edited April 14, 2015 by Razz0r

[Sir PsychoHashy]

Ok ill just go with the one 400w then, i figured it would be a struggle to fit them both in and i guess your right about the heat. I plan on having the fan and filter outside the tent to maximise the room inside. Any chance you could post up a photo of your setup? Im going the check out the tent setup guide that Razz0r mentioned. Im not %100 sure on which way around to set up the filter and fan and I don't know what a cool tube is or what it does . So with your setup you only have one fan drawing the hot air out of the tent?

 

I'll have a crack at explaining it.

 

Outside 

 

So you can see how it's crammed in, which is why I can't use the 150mm ports, and have to have all the workings inside the tent.

 

Inside 

 

1 of the intake ducts is on top of the light, but normally hangs down to the floor, had to put it out of the way as I have been using the tent as a drying room and put some mesh across to hang buds off.

 

You can see how crowded it is up the top, but as I only intended to use it for seedlings and clones I don't need much height.

 

Ventilation/Lighting 

 

CF rear left corner, duct across back, u-turn into cooltube, u-turn again into fan at front left (insulated in earthwool to suppress noise), straight into a fan silencer.

 

And, out the top port 

 

Possibly not the ideal setup, but it's what I had to do in my situation, and it works adequately.  Having the option to put fan and filter outside the tent would create a bit more height availability, but not a hell of a lot.  And, yes, only the one fan, I'm quite happy to have passive intake as I find it works well enough unless you are really pushing the limits.

 

Cooltube is basically a glass tube with the light fitting inside and a reflector on the outside.  Basically enables you to draw air over the globe and suck the heat out.  Supposed to help keep the growroom cooler, and does work a bit, but not as much as some people would have you believe.  In a big tent I won't use it unless I have no other reflector, but it is probably worth having it in a smaller space like this.  There is still plenty of radiated heat released into the growroom though.

 

Hope that helps.

[westozbrownie]

Is there a reason why the ducting is so big even tho it reduces down going onto the cool tube?

 

I have a pretty good idea on how im gonna set it up now. I think it'll take some testing and trial and error to get it right. Im growing inside the house at the moment but need to move it the shed. I think it'll take a bit of time getting it all right and stealthy with noise and light escaping etc.

 

Thanks for your help

[westozbrownie]

Im thinking something like this

[Frank Reynolds]

I could have set my tent up like that, the only problem I had was pulling hot air through the fan, might just be paranoia on my side, but afaik the motors are in the centre to help get cooled.

 

Just a thought, so I push air through my carbon filter with a separate smaller fan.  

 

Cheers