Different Methods to cool a grow box.

I have a growbox, that is about 3ft tall, 1.5 ft wide, and 3.5 ft long. (probably came out weird.)

I'm using a 125 true watt cfl on 24 hours a day. If I don't open my grow box up every 10 hours or so, my temps can reach the high nineties.

I have an intake fan, an exhaust fan, and another fan hanging in the box circulating the air around. I have even cut an extra ventilation hole near the top of the box, yet I still reach high temps.


I'm really at a loss here guys, to the point where im loosing sleep. I cannot for the life of my figure out how to cool the box down. ANY ideas would be VERY appreciated.

The air outside your grow box is probably too hot. You want a consistant ambient temp of roughly 72* on the outside.

Also what kind of fans are you using?

Lastly, if you haven't already, put the exhaust fan on the new hole that you cut at the top of the box, and put the intake fan down near the bottom.


Good luck man!

Be sure you're drawing fresh air in low and pulling the hot air from the top of the cab out. If you have a vent up high then you may be doing more harm than good. Try blocking the top vent and check temps.

What are your room temps and cabinet temps with lights on?

The average temp outside here is around 70-77f. I have my intake a little higher, and my exhause a little lower. I know this is a little bit switched up. BUT! The ventilation hole was originally intended for a second exhast (because it is close to the top), but after I installed the fan and what not, it only brought the temp down and average of about 3 degrees, which is still far too hot.

Xen Cuts said:

The average temp outside here is around 70-77f. I have my intake a little higher, and my exhause a little lower. I know this is a little bit switched up. BUT! The ventilation hole was originally intended for a second exhast (because it is close to the top), but after I installed the fan and what not, it only brought the temp down and average of about 3 degrees, which is still far too hot.

Click to expand...

There's your problem !! You need your outtake fan at the top to be working harder, (if not on full), and your intake at the bottom to be on either medium or equal to the top fan!

Also attach some kind of ducting to your intake fan and have the ducting go either out a vent/window or into another (cooler room) possible with air-con (if temps are really high), or at very least have the ducting at floor level + a 2nd intake fan on the end + filter/Odor Soc/mesh screening etc ...this will assist air-flow and stop bugs/dust/crap etc from entering your grow area and potentially upsetting your plants!

You could also attach ducting to the exhaust fan and lead that out to a different vent/window/room etc.. this will stop the warm/hot air (exhaust) from recirculating and re-entering the grow area at a warmer ambient temp - STELTHY

I put my lights on at night, if it's 18/6 or your flowering try to put the nights on at night when it cools down a bit an open the windows if u don't have a a/c that's what I did. I also put a better fan in my exaust tubes an actually got rid of my intake because the exaust fan pulled air in plenty. Good luck man!!