ok i can help you with just about everything but the light ( dont know anything about it. -The computer fan you got on the dot. You can also use a 9v too. -The light proplem is easy to fix. You can use pvc pips and angle them so less light can come in. -I would say 4 but im not sure about that.Depends how big you want them to get. -Smell is hard. You usually have to buy or make a carbon filter. Or one of those ionic breeze things. Hope these helps a little.
I can tell you now, that won't be enough ventilation. I have a box a little smaller with a 250 w HPS, 2 33cfm computer fans and one big ass fan bringing air in. The temp stays around 81 with the door shut and the light is 20 inches away from the tips of the plants. MY box is 29" by 19" x 48" and the temp is on the high end of the spectrum. Might want to look into downgrading the light, or making a cooling system through the light. For that you'll need more than one comp. fan though. Edit - link to how to cool down the light. might want to look into it. With that, you could probably keep the 400w. http://forum.grasscity.com/showthread.php?t=68977&highlight=air-cooled+hood
so basically, put holes in either side of the light, with ducting leading out from one side to a hole in the box? maybe another computer fan will do the trick?
Hey man, what took longer, building the box or doing the diagram? ;-) Just kidding ya, looks like a nice design. And I'm only jealous of the artistic skills. Are you sure you want access only from the top, not a side door? Tending to your plants bent over that 4' wall won't be fun. Another advantage to a side door rather than hinged lid is that you can just hang the light from chains strung to a couple of eyehooks in the ceiling of the box, much easier to adjust the height and you won't have to build all those blocks on the walls. I agree the computer fan probably won't be enough. You can get a MUCH more powerful tabletop fan at WalMart or Target or Home Depot for $10-$15, and it even comes with a plug! You will then need to figure out how to mount it and channel the air out, Home Depot is a great place for creative solutions. Also agree you can use simple pvc pipe to cut down on light problems at your intakes. Put a 90* elbow on each pipe on the inside and one on the outside and paint the inside of the pipes and elbows flat black, that will cut out virtually all of the light. Speaking of light, your dimensions are a little too big for 250w HID, so the 400w probably is best, just keep in mind the 400w will run hotter so all the more reason to get a stronger fan. You should be able to service up to about six plants in that footprint.
I would downgrade on the light 400watt hps gives out alot of heat. if i were you instead of buying a 400watt ballast and bulb i would buy a couple compact flo's like 125watt's a peice less heat build up good spectrum . ebay is a good place to find good grow lights. cheers.
lol thanks for the advice kerrupt and toasty, but your both tellin me to do opposite things with the lighting... :-\
Not exactly opposite, but I can see where it's confusing. Here's the skinny... I've heard that 250w HPS can cover up to about 9 sq feet max, you are going to be a little above that, which is what I was trying to say. Both of us are saying that the 400w will give off more heat which could be a problem in that sized area. If you don't have foliage covering your entire floor space then the 250w coverage will be good, especially if you have a reflector hood that you can aim the light with and doubly especially if you supplement with fluoros. You want the most light you can, but not at the expense of too much heat that you can't reduce or is too much of a pain to deal with. The best trade-off may be the 250w. FYI my box is 2.5x2.5x4h and I use a 250w switchable MH/HPS plus cfls on all four sides, works fine.
The computer fan uses 12v, so you cant just wire it into a standard outlet. For mine I wired it to a automotive cigarette plug, and then bought and adapter that convers 120v ac to 12v dc. You could also wire it to a car battery.
http://www.oselectronics.com/ose_p17.htm on that site, the 1st AC/DC adapter, it has a list, the one that outputs 12V, if i cut the end off to expose the wires and wire that to my fan it should work?
Get a cell phone charger or something lying around the house. Just make sure it says AC/DC converter. (lol there should be a lightning bolt on the keyboard just for times like this.) Cut one end off and splice the wires, if we're the tiny ass computer fans. Or you can go out and drop 70 on a car converter. I prefer the cheap ass way.
thanks senior ganj i have plenty of cell charges @ my house, should work nicely. Oh! will i need 1 adapter per comp fan or is there a way to wire 2 into 1 adapter?
If you wire 2 per adaptor, it splits the power, so if you need the extra 'umph' i'd say go with 1 per. You can always try it with one, and if they aren't spinning fast enough just cut up another. To wire two, just twist all 3 sets of wires together the same way you would with one.