Getting new equipment, could use suggestions

Hey guys... sorry, this is kinda long but I could use some suggestions. I have been looking through the grow room design and setup forums but I can't seem to wrap my head around the best way to set up the new gear.
I'm currently on my first grow and have a 6ft. Sativa and a munchkin Idica- both bagseed and both are around 3 weeks into flower. I am presently doing a closet grow (5x5x10ft) with 600+wts of T5HO. (I knew all my old fishtank gear would come in handy for something someday.)While things aren't doing badly, I feel that it would be more productive to go HID considering the amount of energy being used by the T5's. My temps presently top out around 83f lights on with a couple desk fans- 1 intake/1 exhaust. Outdoor temps have been 100+f and don't look to drop any time in the near future.

So, my first question would be: should I mess with the new lighting at all in this stage, or will it be counter productive from a stress standpoint? I am thinking I should probably wait due to the required ventilation and trial/error involved to be sure I don't roast the plants.

As for the new gear coming, I should have here next week a 6" AC Hood, 600wt Quantum ballast, and a 6" HO CanFan for 440cfm. I own my own home so cutting the ceiling and exhausting into the attic is what I am thinking I should do. My primary concern is whether I can use the 440cfm canfan to exhaust both the room and the light heat. Is 440 cfm enough to accomplish this task? Or would I be better off running a seperate fan for room exhaust? I realize that if I spliced into my AC ducts to cool the closet, I could drop the temps even more. The problem is that my attic is more lika a crawl space due to the high ceilings. If this is my only option to keep the area cool, so be it- I would like to try and avoid this if at all possible though. What say you?

In addition to the preceding questions, I am specifically interested to know if you were setting this up yourself, how would you go about it?
Any suggestions would be most appreciated.

250 cubic foot grow room requires a 85 cfm fan at an ABSOLUTE minimum (250 cubic feet/3 minutes air exchange)

Add 5% for air cooled light = 85 + (85 X .05) ~ 90cfm

Add 20% if you are adding a carbon filter = 90 + (90 X .20) = 108 cfm

Add 25% for hot and dry climate, more for hot and humid climate = 108 + (108 X .25) = 135 cfm

Add 5 – 20% more for length of ducting, amount of turns, etc.

So at an ABSOLUTE minimum you would need about 150 cfms. Your 440cfm fan should be fine exhausting both light and room and should keep the room pretty near the inlet temperature. If I was doing it I would go scrubber > cool tube > fan > exhaust into attic and check the temps before I started growing.

Dystopia said:

250 cubic foot grow room requires a 85 cfm fan at an ABSOLUTE minimum (250 cubic feet/3 minutes air exchange)

Add 5% for air cooled light = 85 + (85 X .05) ~ 90cfm

Add 20% if you are adding a carbon filter = 90 + (90 X .20) = 108 cfm

Add 25% for hot and dry climate, more for hot and humid climate = 108 + (108 X .25) = 135 cfm

Add 5 – 20% more for length of ducting, amount of turns, etc.

So at an ABSOLUTE minimum you would need about 150 cfms. Your 440cfm fan should be fine exhausting both light and room and should keep the room pretty near the inlet temperature. If I was doing it I would go scrubber > cool tube > fan > exhaust into attic and check the temps before I started growing.

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Thanks bro, I appreciate it.
I understand everything you said but here is where my lack of knowlege comes into play. Would I want the scrubber (intake) in the coolest or warmest location (up high or down low) ? I would think high to capture any remaining trapped heat, as long as the room turnover rate is acceptable, but I don't know. I would think it would be more beneficial this way by drawing cooler air up through the entire closet. Of course I can always trial and error with placement I suppose.
Damn, I feel like a moron with this hi-tech stuff.

Thanks again.

You want the scrubber on the exhaust, so up high. I would go scrubber-->light-->fan-->out. I think that size fan should work pretty well, depends on the intake temps.
In theory, the hps should actually give off less heat than the equivalent wattage of fluoros, but it's all coming from one source rather than being spread around.

here is my setup http://www.youtube.com/watch?v=sjbLYNePQGA im venting in to the attic also, your fan and stuff is more than adequate to cool a 600, i would put your filter up as high as you can get it then run the duct down to the hood and have the fan pulling on the other side of the hood and then out to the attic, this is what im doing here, i have put a small elf filter on the end of the hoods, since you are drawing air through the hoods you need to make sure and seal them up good with a little silicone or caulk or something but it works real good

OK, you’re going to be sucking about 400cfm out of that room. The first thing you got to worry about is if your inlet is big enough to allow 400cfm INTO the room. Your fan will work harder and make more noise if your inlet is insufficient. You can cut a square in your door and put one of those vent covers over it…but you have to worry about light-proofing your room. You can use a louver or backdraft damper that closes when the fan is off, if you’re not running the fan during lights-off. The best option would be to use a fan for the inlet that is close in CFMs to the exhaust fan. The inlet should be as low as possible.

Ideally, you want the scrubber (or inlet to the exhaust system) diagonally across from the inlet (opposite and high from the inlet)…but that may require more ducting and turns that decreases the efficiency of the fan. This is where your oscillating fan comes in…it moves the air around in the room eliminating hot spots. I would stick the carbon filter right on the end of the hood, or wherever else is convenient, trying to keep ducting to a minimum. If you find you’re getting a hot spot, then adjust your oscillating fan or stick another one in there.

Hairy Bob-
That makes perfect sense. I guess if you can keep a single isolated light source cooled, or at least cooler by exhausting it elsewhere, my temps shouldn't be any worse than they are presently with the t5's....hopefully. And I just realized that I worded something incorrectly on my last post. When I said intake on the scrubber, I just meant the inlet to the lamp (pre lamp- not actually intake).

fat sam-
Thanks for the link. I will give it a watch.
I appreciate the heads-up on sealing that hood. I will definitely make that happen.


What you gent's have been suggesting was the way I saw it coming together, but I wasn't sure that was the way it needs to be done.
You guys rock- thanks for the suggestions.

Dystopia- thanks man.
With my setup presently, I keep the closet door open to help with ventilation. The room is pitch black to account for the door being open.
With the new gear, I figure I will butcher the bottom of the door and put the largest intake grille that I can find- probably in the neighborhood of 2x2 or 2x3ft.
If that doesn't suffice, I will force feed with an additional intake fan roughly the same cfm.

Stonefish said:

Dystopia- thanks man.
With my setup presently, I keep the closet door open to help with ventilation. The room is pitch black to account for the door being open.
With the new gear, I figure I will butcher the bottom of the door and put the largest intake grille that I can find- probably in the neighborhood of 2x2 or 2x3ft.
If that doesn't suffice, I will force feed with an additional intake fan roughly the same cfm.

Click to expand...

A 2X2 grill should work just fine, so long as you don't have light issues.

fat sam-
Thanks for the vid- one pic is worth 1000 words. A video must be worth at least 5000.
The only thing it looks like you are missing is a stash box for munchies.


Dystopia- thanks for the confirmation on grill size. Light leaks will be a non-issue.

good luck dude. Hopefully you picked up some good reef keeping habits. There is alot of similaritys between the two hobbies. You should be pretty high on the learning curve.

desert fox said:

good luck dude. Hopefully you picked up some good reef keeping habits. There is alot of similaritys between the two hobbies. You should be pretty high on the learning curve.

Click to expand...

Thanks DF.
Always enjoyed the reefkeeping thing but maintaining 300G of water volume and a tank full of stony corals became entirely too time consuming.
I dumped all my MH lighting but fortunately, I never sold my 2 IceCap ballasts, retrofits, Tek hood, and my testing equipment- they were stashed for a rainy day. I knew there would be a use for it again one day.

I look forward to getting the new equipment and seeing what I can do with some quality seeds.

haha i just found this thread.... aaaahhhh memories.... check my youtube link.... i made some improvements