Jump to content
  • Sign Up

Cool tube + exhaust fan help

Recommended Posts

Hi dudes I have this grow closet constructed. Dimensions are 1.95m H x 0.93m W x 0.83m D

I have put a 4" Ezi Air fan inlet at the bottom and 4" Ezi Air fan outlet at the top and also a bathroom extraction fan for more extraction but when I use a 400MH the temps can rise to 35C. Obviously the summer temps aren't helping with the grow box inlet and outlet being directed into the garage but what I need to know is:

1) Where should the light sit in the box? Should the hood be at the top of the box with the plant sitting on something higher then lower as the plant grows or should the plant be on the floor with the light being lower and raised as the plant grows? Wouldn't it be easier to control the heat if it was at the top all the time?

2) With a cool tube, what is the best way to set one up? Ducting from side to side with a 4"/6" fan? Where does the fan sit in the setup? Could I use the 4" Ezi Air fan outlet at the top for the cool tube/ducting? I'm new to the cool tube side of things - but its becoming obvious its something I need




Link to comment
Share on other sites

The problem is you used computer and bathroom fans instead of one purpose built for indoor gardens.  Spend a few hundred on a decent fan, cooltube, carbon filter and insulated ducting then go filter, fan, ducting, cooltube and then ducting all the way out of the growing area.  You could also run the cooltube on it's own with a separate fan but unless you're growing on a large scale it's not worth it.


The light should be as close to the plants as you can get it without burning them.  Hold your hand where the canopy is for 30 seconds and if you feel comfortable your plants should too.  The hot air is going to rise anyway so it's not really going to make any difference to ambient temperatures where the light is but since the plants will care about the intensity of the light get it as close to them as you can.

Link to comment
Share on other sites

Yeah you may need a proper inline fan especially using cooltube lighting.. The light should stay about 12 inches above the plants and adjust up as they grow.
You will need a carbon filter as all the air you are ducting out of the grow room will stink if you don't have one.. If it gets to 35 degree the cooltube setup wont bring it down alone. You will need to bring cool air in at the bottom.
See my pic. I have an inline fan inside the insulated box at the top of the tent.. I don't have my filter set up yet but the carbon filter will connect to the left side of that box so that the fan can suck air through the carbon filter and blow it through the cooltube and all the way out the other side of the tent... The light is on yo yo hangers so i can adjust its height up or down.


Link to comment
Share on other sites

Inside the garage gets to about 30C in summer and obviously in winter it'll get considerably colder to about 15C where I live, so it's a situation that works both ways. In winter I will need to heat the garage. But in winter if I don't use a cool tube it might be OK. Smell really isn't an issue so there is really no need for a carbon filter with my setup. Last grow I had of Super Skunk (which I'm doing again) didn't give off much of an odor up until the final couple of weeks anyway. I'll set up a cool tube or hood like in the diagram I've knocked up and go from there. Any pointers?



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using the community in any way you agree to our Terms of Use and We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.