Help with cabinet/ventilation, temp issues

[L-G-C]

Ok so I've been setting up this cabinet for a first time grow, haven't actually attempted to grow anything yet. I've constructed my light fixture which will use (8) 23w CFL's @ 1600 lumens each. The measurements of the cabinet are 23"W x 17"D x 42"T, so 9.5 cu. ft.

For ventilation I started with a 44cfm computer fan. I had heard mixed results on these but figured I'd give it a shot. The temps were way too high so I added a 4" inline duct fan (not centrifugal or anything, it's a $30 65cfm unit from Home Depot). This helped out a bit, but still, with both fans running at the same time, I still get 84 degrees at about 4" below the lights. About 20" below that, the temp is 74 degrees. For ductwork, it's about 2 feet to my ceiling from the top of the cab, and then another 4 feet or so in the attic where it terminates at a roof vent.

My question is should I be worried about these temps being too high? I've read that CFL's are supposed to be a few inches from the plants, so is 84 too high for that distance? I'm thinking it's close enough to where I can get a plan to grow just fine, but once the weather warms up I might have some issues. Also I don't have any sort of carbon filter attached, so I'm thinking once I add that my temps will rise even more.

I know they have nicer fans than the ones I have, but they're way more expensive and many of the ones I've seen really seem like overkill for my setup...I don't really want a fan that pulls more watts than my light fixture. Is it just a situation where I need to just buy a bigger fan? Or am I just going to get those temp readings at that distance from my lights no matter what, since I have 8 of them in such a small space?

If anyone needs pics I'll take a few and see if I can get them posted. Thanks for any help you can give me.

 

[PrairiePoet]

You need to lower the temps.

CLF's do run at a lower temp than HID's, but add enough of them and they start to put out enough heat that you have to deal with it. I've ran 6 85 watt CFL's in my little closet and it really heats it up. One thing you can try to lower the temp is to run some ducting from the largest fan to the top of your reflector. If you don't have a reflector, then look around the DIY area, several good threads there. That should help, but not sure if it will be enough. Once the outside gets hot, and you add a carbon filter, you will need to get a more powerful fan.

 

[L-G-C]

Ok thanks... yeah I was heading in that direction but I wanted to try the other options first...I guess I just wanted to hear it from someone that's done this before. So here are a couple of pics of my setup. I used a 6" duct that I cut open as the reflector, then cut it into strips in hopes that it would let the heat dissipate a little better. My original reflector was just flat wood with no vent holes and it was way too hot. I'm thinking this time I might try to go back to a flat hood but mount the duct work directly to suck the hot air out that way (through the light fixture).

I found one of the 4" vortex fans for just over $100 online somewhere...does anyone have a reccomendation for something that would work better for me? I believe that one is 165 cfm or something in that neighborhood. I'm thinking that should be plenty for my application (9.5 cu ft plus a future carbon filter)?

Thanks again for the help.

 

[PrairiePoet]

Thanks again for the help.[/IMG]

You're welcome! I got a lot of help from here on 420, directly and indirectly, so I try to give back.

Any way you get the fans to be pulling the hot air directly away from the lights, and then exhausting it out helps. How much it helps... ??? Have to test it.

Also be aware of where you are exhausting to. You don't want that air coming back into the grow.

Good Luck Brother...