temp woes

[demonseeder]

First off, this is a great community and I've already learned a lot from the plethora of good threads here. Alright, so I'm stumped as to why the temp in my closet is so high. I haven't started using the closet yet, so I'm not in too much trouble, but I've got some girls in a small cab vegging right now about 2 weeks along.

In a closet, 4' L x 2.5' W x 7.5' H I've got a 600w hps with a DIY cool tube (hurricane glass), 4" intake to 4" exaust hooked up to a 250 cfm duct fan. Then, for the closet air I've got a 6" intake and a DIY carbon srubber (similar to this but 18" long, 4" inner diameter 5" outer diameter) hooked up to a stanley blower (which I hear is about 265 cfm?) for fresh air. The intake temperature is 74 F, but the cab is getting up to 87-88 degrees

I've used the ventilation formula found in the old OG FAQ, but the numbers aren't coming up right. Using dT = Q / (V x P x C), I have
dT = .6 / (.125 x 1.2 x 1.02)
= 3.9 + 23.3 = 81 degrees F

I'm really disheartened by this discovery, as I had hoped to put the girls in soon.. So IC community, I beg of you please help me out. Thanks in advance.

 

[New Holland]

Mate I wish I had an answer for you. I'm about to you the same formula to work out what my temps will be. I read on OG that people got pretty close what they calculated. But they were all actually ROOMS and not closets.

Maybe that formula only works down to a certain size?. I'd like to hear other peoples comments?.

 

[sogman]

Fuck! I hope I don't end up overheating too!
I'm only gonna run 1 400 watt though. Hopefully I'll only need to vent the hood, and not the entire closet. Heres my set up, it's almost identicle in size to yours.
http://www.icmag.com/ic/showthread.php?t=41702

 

[demonseeder]

ok, so get this. I removed the cool tube fan and the temps dropped to a few degrees above intake. Maybe use a smaller fan? it was a 6" fan reduced to a 4" intake, but I figured 250 cfm would be alright to take a hit in power lost..

 

[demonseeder]

well, I'm back where I started again, the temps rose to the 90s. h: Don't know what happened last night to make it cool, but it doesn't really matter now.

 

[Hey Fisher]

I run 2 600's in cool tubes. you need all of 6" to keep em cool. I'd run cool air from OUTSIDE the room through your light and immediately out the closet. Even the duct work will throw off heat into your closet. Those 2 cool tubes were in a 4x5x7.5 closet. And I had to also run 2 6 inch fans blowing into the room, and 2 out. I just used inline duct fans available at Home Depot for about $25 I think. 2 in, 2 out, and 1 for the light. Hope this helps. I know how frustrating it can be. When in doubt, move more air.

 

[demonseeder]

alright let me get this right. You use 6" duct for the cool tube? I currently have 4" I have a 5-4" converter on the cool tube, guess I should change that to a 6-5" (wonder if the depot stocks them) Hey Fisher, you've inspired me to keep fighting these temps with your closet being roughly double the size, with double the light. I'm going to go get some 6" ducting, would insulated help? Also, do you think the mylar lined walls are causing the temp to rise anything significant?

 

[Hey Fisher]

The problem with insulated duct is you can't see if you have the duct pinched off. With the cheap stuff you can see what you got and you know you won't have flow problems. Just make sure you use enough fans to move the heat through quick enough. I don't think mylar is really an issue. It does more good than bad. Just remember that the key to heat problems is simple, remove the heat.

On a side note, I've found that a Sunspot6 reflector runs cooler than a cool tube, and more effectively spreads light. Not sure if you have room though. Just something I'm noticing now in my new setup.

I'll look and see if I have any pics of the 4x5 closet setup still on this computer.