Vent problem

Hey all!

I had another user name on here but for some reason I cant log into it any more. Ill keep this short and sweet and if any more info in needed please let me know.

I am growing in a 2x3x4 box I built. That works out to be 24 cubic feet. I am using a 160 CFM fan attached to my carbon filter in the grow area. At the bottom of the grow area, I have cut out a square hole and attached a standard home register grate with a very breathable filter. I CANT GET MY BOX UNDER 100 degrees!

This was not a problem before because the doors to the box were open during veg. Now that I am into flowering and need periods of darkness, I wanted to close up the box and started running the vent setup (Obviously odor will start to be an issue soon as well).When it was in veg with the doors open it was never above 78 degrees. What I cant understand is how it can get so hot with the 160 cfm fan drawing out the air through the filter. THAT IS WAYYY OVERKILL for my size grow room and still It got to 104 degrees.

Is there something stuiped I am missing?

Please help!

Thanks!

Plants shouldn't raise temps that high. So the only thing you are missing is letting us know about your lights and anything else in the box that could raise temps.

Those high temps are without the plants in to box... 400wt Hps ic been running the same setup for the last 5 days with the doors open with no problem

My guess would be your lights aren't sealed and you aren't pulling air through them. Oh and are you pushing or pulling? With a fan you always want to setup to pull as much as possible and keeps ducting runs straight as possible. Pushing with a fan is very inefficient.
hth

I'm pulling through the carbon filter.... I even have an inline at the end of my duct. I'm running 4 inch. I assumed it would have a better charge

Are you pulling the air threw the hood? Or what kinda hood do you have?

I'm using a friends. It's not vented and the ballast is directly attached to it. I guess I'm just going to have to take the lights and ballast out and try a sky light kind of setup.

An un-cooled 400 watt bulb and the ballast in a small box??? All that's left is this, I guess:

Try doing this first. Get a small table fan or clip on fan and have that fan "blow" over the lamp hood and ballast. What could be happening is you are developing a heat pocket around your lamp that will end up in raising the heat like you are saying. If that dose not fix it then you might wanna look at a air cooled hood and a remote ballast.

Joking aside - that is a rather small space. True, the heat pocket can build up, but I really think that heat needs to be pulled out of there and not just circulated. I can't even picture how the carbon filter could be above the light in that space - that would also allow the hot air up top to be drawn out.

With out pic,s we can only speculate what's going on.

ill post a pic or 2

What is the temperature in the surrounding room?
Where is your thermometer in the grow box?
Is your filter located at the top of the box?

Pictures will be helpful. I think a circulation fan will also be helpful.
A bare bulb w/ballast will make it a challenge to manage the heat.

If by skylight you meen getting that ballast out of the box do it. I'm thinking your just gonna cut a hole in the top and mount the light on outside of box.

I did realize that my box is actually 5 foot tall. Thats still is only 30 CF
here are some photos.....

Light, Ballast, and carbon filter


This is with the top section removed. usually this hole would be boarded up


160 cfm squirrel fan at the top rear of the box


duct work running out of the house


exiting the house. there is a inline duct booster near the T

Yeah try putting a fan to blow over the ballast hood and lamp. Toward the filter. Is there any way to get the box closer to where you are venting to. And straiten it out to not have less bends.

unfortunately, there isn't a lot of room to move it any closer than it is. when you put your hand over the carbon filter it doesn't have very much suction. Iv never used a CF before so i don't know how hard they should suck.

Well add the small fan. And it is more about what it feels coming out the fan. Maybe even get the cf closer to the hood to help pull heat.

if its a wooden cabinet,,,then divide it, put a sheet of glass in to seperate the top third and put in runners like a dresser draw...this way the glass can go in several spots if need be.....also i noticed u have a little duct fan...is that in the same line as the big inline fan?....if it is take out the little one, its resticting the action of the better fan....just a thought

All in all, it looks lpretty good. Where is your thermometer located at? ambient temp in room?

That is a long run of flexible ductwork. Lot of resistance. In addition, I am not sure why you are exhausting outside. Assuming your odor control is OK, you could try an experiment by removing the ductwork after your fan & exhausting back into your room. This should demonstrate the max performance of your fan for temp control. I am also assuming that you have adequate air intake into your box.