Need Help Cooling Cab(w/pics)

[enigmatik]

Arrite so we got my friends cab up and running and its a friggen oven in there, got up to 104f before we shut off the lights.

Here's the specs:

-Measures 55"wide 22"long 42"tall (about 30 cubic feet)
-Running 6 65w CFLs. (cool white 4100k)
-Walls and ceiling completely covered in mylar/aluminum tape.
-Shelf with mylar dividing cab in the middle.
-78cfm 120mm computer fan with a carbon scrubber for the exhaust.
-2 1.5" diameter passive intakes w/light traps.

And the pics:
(pardon my friends sloppy attempts to paint background)











notice the light trap/intake in between the ballasts of the CFLs


the bottom light trap/intake




scrubber was made with some gutter guard mesh and panti hoes







So we think the problem is in the intakes/light traps. They block the lights amazingly but there just isn't enough airflow. Also, fan probably isn't running anywhere near 78cfm.

Our ideas so far was to replace the 78cfm with 100cfm for the exhaust and use the 78cfm for an intake on the opposite wall on top by the lights.

There are also plans to put 2 100 or 150w CMH in between the CFLs (probably have to bake-a-round cool tube them)

So please give suggestions, criticism, comments on how to cool this cab down and what you think of the design.

Thanks in advance!
-enigma

 

[Hawk]

I think you need lots more airflow.

I've come to the conclusion CFL's aren't all that cool. A couple of 23 watters, sure. But then you're only dealing with not many watts. You've got 390 watts. When I was using ~250w of CFL light I was really surprised how much heat they produced. I kept hearing how cool CFL's were. Yeah right. I had to blow tons of air all over them and out an open closet door to keep things cool. More and more, I believe watts = heat and watts are watts no matter what kind of light source it is. In other words, 250w of CFL heat ain't that much different from 250w of HID heat. Probably the biggest difference is in the radiant heat produced and how the heat is concentrated [shrug].

You could remote ballast your CFL's. That should help by moving the CFL ballast heat out of the cab. It would require some dismantling of the CFL bulbs and a re-work of how they are mounted.

$0.02

 

[Guest]

Hey HAWK---where are the ballasts in a CFL?????????????????????????????

 

[Hawk]

Hey HAWK---where are the ballasts in a CFL?????????????????????????????

They are in the base of the bulb.

 

[Hawk]

Not long ago I disassembled a CFL to remove the ballast as an experiment. I question the degree of impact with a small CFL like the one pictured below [shrug]. However, I have a pair of 105w CFL's that I do think would be worth separating. The base of those bulbs (where the ballast is) gets really hot. I no longer use any CFL's as I decided they didn't make sense for me. But if I did use my 105w's, I'd remote the ballasts (depending on the circumstances).

 

[bluebottle]

enigmatik, My new cab is just a little bigger then yours but I'm using a 400w hps on a cooltube, my temps were 78-80. During veg, instead of running my 400, I was running 3 (23w) cfls and it was running temps of 85-87. I think the cooltube made all the difference. I know you've spent some good money on your cfls and probably don't want to switch over but just wanted to let you know my experience. Good luck man!

 

[Hawk]

Here's the 105w CFL ballast.

 

[sunnydog]

See the cooling links in my signature.
Might help.
And,yeah it seems flourescents make lots of heat too.
Dont think I would take on apart, seems like a PITA, I'd just get a HID with a remote ballast.
Also, make BIG intake holes.

 

[enigmatik]

Hawk- my buddy wired up the ballasts remotely but it he said it barely helped, the flouro tubes themselves put out a ton a heat on their own.

bluebottle- it's not my cab, it's a friends and i didn't spend the monies.

sunnydog- those are some brilliant ideas you got there, just my friend has no where to pull in cold air from and the ice chest would melt way too fast in our climate and he's not up for the maintenance of it.

So we replaced the exhaust fan with a 100cfm fan and hooked up another 100cfm intake fan on the opposite wall. All that and with the remote ballasts and it's still cookin at 93f.

This heat issues drivin us crazy, really wana get this thing rollin soon.

Would another intake fan and exhaust fan(100cfm) bring the temps down to where they should be or is there a better way no one has mentioned yet?

Thanks again!
-enigma

 

[Hawk]

Hawk- my buddy wired up the ballasts remotely but it he said it barely helped, the flouro tubes themselves put out a ton a heat on their own....

Good to know. I've been meaning to do a simple "cardboard box test" with my 105watters to measure the difference but haven't gotten around to it.

Hope you get it sorted soon.

 

[PharmaCan]

As noted by several others, you need bigger intakes. Also consider:

1) Make sure that your air flow is up -> around the lights -> exhaust.

2) Add a couple small fans to blow air up and around the lights.

3) Ditch the mylar and use flat white paint. I know that sucks, but it'll run cooler and the reflectivity is about the same.

PC

 

[messn'n'gommin']

-78cfm 120mm computer fan with a carbon scrubber for the exhaust.
-2 1.5" diameter passive intakes w/light traps.

120mm is what? 4"...4-1/2"? I think that equates out to about 12-1/2" to almost 16" exhaust and you have about 3-1/2 square inches of intake. I suggest you get a 12" by 12" darkroom louver and,taking into consideration of restricted air flow rates, that will give you somewhere in the neighborhood of 3/1 to 4/1 intake to exhaust ratio.

Namaste, mess

 

[HerbGlaze]

Get a comp fan just like the one you had but make it a intake fan so turn it around that will really help

 

[THENGINEER]

I run a cab just like yours, with a 250hps...listen up

First off, you need more intake. Those you have now are pretty small, if thats the only size pipe you have, add another 4-5 of those. DO NOT USE FANS ON THE INTAKE.

Now for the exhaust. Problem is, your using a fan which was not designed to work under load (ie, carbon scrubber). Try ditching the scrubber for now and see if that solves the problem. You wont need it until you flower anyways. To run a scrubber, you need a cage type fan. I dont know where you live, but where im from, you can get a 110cfm cage fan for 30 bucks, you just need to know where to look. Go to your hardware/renovation store and look at bathroom fans. Tell the guy you are going to be running through a bit of duct before outside, so you need a cage type fan. Like I said, I picked one up for 30 bucks, and its 110cfm.

You are also going to need to get yourself some airflow around the lights/plants so you can get them as close as possible. I suggest ditching your current exhaust fan and using that for airflow in the cab, and then getting yourself the right exhaust fan right away.

That should fix your problems. Remember, add some extra intakes for now and remove your scrubber. If the temps fall, your gonna need a different exhaust fan. Also, ditching the mylar and going flat white is good for 2-3*C (In my cab at least)