Okay, so I created a dresser grow box and I'm having immense problems with heat. Thankfully, my girls aren't in there yet; they're germinating, but I procrastinated long enough without testing my setup, that I'm only testing it now, and I'm finding temps get to approximately 98 degrees, and that's not during the hot parts of the day (which is when the lights go off). Obviously, this is a problem. I have 2 case fans (PC fans); the intake is a 120 mm 11.27 CFM and the exhaust is an 80 mm 34.23 CFM. Now, initially I was going to use the smaller fan for intake, and the larger for exhaust, but I read you want more exhaust than intake. My dresser size is just over 11 cubic feet. I may have failed to mention that I'm using 2 CFL bulbs at 250 watts each for a total of 500 watts in this space. The inside is painted flat white, and I'm using aluminum duct above each light for reflectors. So, the question is this. How do I bring down my temperature 15 degrees without incurring a bunch more cost. I have 2 more 80 mm fans and a 120 mm fan left, so using those is a possibility, but I was supposed to use those for my flowering dresser which will have 420 watts CFL in it. Either way, I don't want to keep cutting holes in the bottom of the dresser, as it will start to limit my grow space. Anywho, I need to do this in like the next 24 hours, since my seeds are already germinating. I may have overdone it on the lights, but I was planning on growing 5 or 6 plants at a time. Thanks for reading, and any good ideas are appreciated.
Make sure exhaust fans are on top, intake on bottom. I ended up stealing the A/C from a vent in my room for my grow box. I used a cardboard box and some small air ducts to redirect the cold air from my vent to my grow box intake. Worked like a charm. Temps went from 95-105 down to 75-80. Perfect
You should post up a picture of it. Could just be a air flow problem. My closet had always been hot (low 90's sometimes mid 90's) I put in a little 4" fan blowing across the lights and now it generally stays about low to mid 80's usually right at 80 though. I've also thought about routing the a/c into the closet but we don't run it much (not my choice) but the vent is close to the closet anyway so on a hot day I will turn it on and open it up. If your intake and exhaust are right rig one of your other fans up to blow across the lights toward the exhaust and see if that is enough. The fan I used for it I got for $5 or so at walmart, best purchase ever made there, I've seen a lot of people on here with the same one. I don't know how many plants you are planning to veg in there but 500 would be enough for 9 fully vegged plants. So maybe the answer is as easy as less light.
Thanks guys. I'll post a grow journal very soon which will detail the setup. Tonymon, to answer your question I'm just looking at vegetating 5 at a time right now since most of my grow space is taken up by fans . I think I might have figured it out. I added another 80mm for intake (both intakes are on the bottom), AND I added a 10 inch box fan in there blowing air up and across toward the lights for the most part. This will help when the plants are getting bigger anyway. I bet it will be enough, but right now I'm waiting for the temp to stabilize and I'll go check it. At least my thermometer has a memory for the high and low temps. I will probably be moving my seedlings (provided they've broken through the peat) tomorrow, if not tonight. We'll see.
Lord Sat! Check my journal!!! I had the same probs 90+ temps! 1st thing I did was move the AC duct from my bathroom to my closet. temps decreased by 3-5 degrees. 2nd and the single greatest thing to do IMHO is install PC fans in the cieling and exhaust the closet!!!!! I installed 120mm fans blowing into my attic, moved my ballast along with my blower higher up, and under the PC fans, and BOOOOOOM!!!!! 15 degrees COOLOER in 10 minutes!!!!!!!! I got pics of the setup in my journal, hope it gives you some Ideas!!! Good Luck!
Me too, except I just removed the vent and jammed a connector in there, which I attached my duct to. It's ugly as hell because it goes across the whole room, but it's a spare bedroom, so I don't see it much unless I'm in there for the plants.
Ya then I would say if it's still too high pull one of the bulbs and replace it with a smaller watt that won't get that hot.
Okay. Well, this is a dresser, basically 46"L x 16"W x 26"H, so I can't do all the cool ductwork and whatnot. To address darookie2000's question, I have 4x105 watt CFL for vegetating. I'll deal with those heat problems when I get there... So, here's an update. I installed a second 80mm fan, and added a 10 inch box fan. With both lights on I still didn't get below 96F. So, I turned off one light. All 5 pots will fit under it fairly well. With all of the fans on, the temperature right now at the top of pot level, directly under the light is 89F. I can get it down as low as 88.5 or so if I reposition the fan. This will have to suffice until I come up with a mini air conditioner. I wish I could grow in a whole room, but unfortunately living in an apartment doesn't afford that luxury.