Almost finished building cab...need your help!

After almost a year of reading and researching I've have finally moved into my own house and built my first grow cabinet!

I have divided the cab into veg / flower and hope to flower 3 plants at a time. I plan on utilizing LST technique to keep the plants heights down.

So here is my question:

the dimensions are 49" x 32" x 24" for the flowering (hps)portion and 49" x 15" x 24" for the veg (cfl)side.

I already purchased a digital greenhouse 400 watt hps lamp and ballast and will be using a cooltube. Are my dimensions too small to squeeze a 400 watt light in there? Will it be almost too hot to keep cool with a decent fan??

Check the pictures and tell me what you think!

My experience says you will need some good sized fans to keep temps ok in that small space. You can have a look at mine. I struggled with heat until I added another inline fan 6" sunleaves windtunnel.

So you basically have a 2' x 2.5' footprint. I think 400w might be overkill.

A 400w is made for a 3' x 3' room, so i dont think its too overkill

As long as you can fight the temps I say the more watts the better

I recommend getting a large inline fan (500ctm +) just as picasso said, and vent all that hot air from your cool tube outside the box. That way the main source of heat is being exhausted. Also have some passive intake holes on the bottom of the cab to let fresh air enter.

I had something similar to your dimensions but a little taller. I have used a 400 and 250 in it. The 400 i use in the winter and the 250 in the summer due to heat. If you can manage to keep the temps down with the 400 you will enjoy fatter nugs.

I'm building a 400w cabinet and its tucked in my closet. The temps do get pretty high so I am vegging with CFL's til I get a stronger fan. Link is in the signature. I'll stay posted to yours to see what you come up with. Good luck!

Wow, thanks for the input. I've decided to stick with the 400 watt and give it a go. I going to wait and see how the temps do when I'm ready to flower ...If need be I'll take down the veg divider, open the entire cabinet for flower and build another cab for veg.

I drew up a quick design of what I'm thinking for ventilation and what not...I'd love to have your opinions!

You should consider splitting the Veg room in half (top and bottom). Keep Mothers on the bottom and clones up top. Mother plants would get large, so you'll need the lights up high. Clones need their lights much closer.

Just a thought.

Second cabinet for veg and mamas would be better imo

Your diagram looks solid, the only thing i could notice is that make sure you use a cool tube and not that shitty reflector, its very crucial to this small setup.
Also, you DO NOT want to coniue the ducting through the entire cab and out the other side. You want vent the entire cab of heat, and to do that you leave one side of the cooltube open to suck the air from the cab, ya dig???
One last point, vent all this air out the cab. You should attach your carbon scrubber to the end of the ducting outside the cab, Then your taking all of your hot skunky air outside of your cab and though a carbon filter.

beta0701 - thanks for the input. the reflector will be replaced with a cooltube soon...I just haven't put the cooltube together yet. So you're saying I should pull the air through the cooltube from the cabinet and not fresh cooler exterier air? I'm confused because I thought that most people were in agreement that pulling in warm cabinet air is rather self-defeating? Or I guess it depends on the fan power and the intakes and all that jazz.

Anyone have comments on how to cool my cabinet? How should I construct my intakes? Light proofing?

If you are bringing cool outside air directly into your lamp, you are bypassing the entire grow room. The PLANTS need fresh air! Not your light. The light is perfectly happy with old stale air.

A couple small holes at the bottom of your cabinet will allow fresh air to rise through your tent and out through the lamp fan. Make sure you screen these openings somehow so that light (use squiggly tube) or bugs (mesh screen) can not enter.

You need more adjust ability on your 400w lamp. Purchase small-link chain. You need 2 pieces about 4ft long. Screw in the ends to the roof, then use your hooks and loop the chain to adjust height. Use dryer hose for your lamp ducting, it will squeeze up to any length.

That diagram looks pretty good, but like someone before me said, make sure your plants get fresh air on them. Also, you can put your ballast in that small compartment above the veg portion, and also get a small computer fan to vent it too.

HiScores said:

beta0701 - thanks for the input. the reflector will be replaced with a cooltube soon...I just haven't put the cooltube together yet. So you're saying I should pull the air through the cooltube from the cabinet and not fresh cooler exterier air? I'm confused because I thought that most people were in agreement that pulling in warm cabinet air is rather self-defeating? Or I guess it depends on the fan power and the intakes and all that jazz.

Anyone have comments on how to cool my cabinet? How should I construct my intakes? Light proofing?

Click to expand...

Your not pulling in warm cabinet air, your pulling it out

All the hot air in the entire cab will be sucked out if you leave one end of the cooltube open. This serves as a dual purpose. 1) it cools your cab because you can suck all the hot air out the cab. 2) the smell will be greatly reduced because the entire air in the cab will be pushed outside through a carbon filter

To achieve this you will need a large fan 400-500cfm +

Just make sure your carbon filter is OUTSIDE the cab and you are sucking all your air OUTSIDE the cab. Otherwise you would defeat every purpose of ventilation.

You can build light trap vents. Really hard to try explaining in words. But it looks like what goes on the outside of your house where the dryer vent comes out. Looks like this http://www.doityourself.com/invt/4640967

For a light trap, just connect your exhaust (or inlet) to an accordion type dryer hose. Then pull it out to length and put a couple bends in it. Light doesn't go around bends!

For odor you can vent everything into a second tent and put an ozone maker in there. Then vent that chamber to the outdoors (not the attic or any living area). The ozone will scrub the air before it goes out and no one should smell a thing. The scrub chamber doesn't have to be very big. A large cardboard box would work.

You've got passive air intakes but I don't see an exhaust port. You need to have a fan built into the top or maybe have a flange / dryer hose that runs through an inline fan and out through the carbon scrubber. Or you can put your fan(s) in the intakes and force it through the top outlet(s). Heat is a bitch; that's why I bought LED's and T5's this grow.

In an ideal world, you would have two fans, one pulling cool air over the bulb and blowing it out of the growroom, then another to exhaust air from your growroom through a carbon filter/other smell removing appartatus. Even with a cooltube, some heat will escape into the room, and if that is then used to cool the bulb, it creates a viscous circle as the cooltube is not working at full efficiency.
That's not to say that it's wrong, if your temperatures are low enough to allow this, then it's fine. You will have to keep the plants a few inches further away from the plants, but it will still be much cooler than a bare bulb (I can hold my 600w cooltube all day long, it's just warm). I personally run it in the same way, but have a larger space and lovely cold outside air coming in. When it starts getting warmer in summer, I'll probably have to change to the method I described above.