Grow tent Heat issues

This is my second grow and I have decided to use a 400w HPS this time but I'm starting to have issues with heat. First the tent is 6' x 3' x 2' and I have a ducting system to pull heat from the reflector. Im using a 70 cfm fan to pull from the the light via ducting and a glass shield on the HTG supply reflector, then a 100 cfm to push it into the attic. The tent stays about 83deg in my room with it open, but since i like sleeping in the dark I have to find a way too keep it cool. Unfortunately the tent is in my room on the 3rd floor or an apartment, so the temps are always higher. My room stays about 78-80 deg. I have recently added a windows A/C because I usually have the windows open but I'm pretty sure I see money flying out the window. Any idea how to keep a 3rd story bedroom cool? Or any ways to make my light cooling more efficient.

Here are two pictures to help you visualize.

Thanks for any help

Bigger fans will move more air in less time. Might I ask why you went with the size fans that you did? Honestly I would be using a 6" Vortex fan (for example, there are better brands) on a system like that. I have a tent (4x4x7) and I am using a 4" for intake, 6" to cool my light, and another 6" with a filter for exhaust.

So yeah, I'd try a bigger fan before the A/C. If you can get the tent temps to the same as your outside room you will be fine.

Oh...what ARE you using for intake? A passive air flow?

I accually dont have a intake that I think is mostly the problem. The only holes i can have a intake is the top holes because the bottom ones are against a wall.

I am having the same problems with heat and i am on the 3rd floor as well and am using a 6 inch intake fan with a 6 inch to cool my 2 x 600 watt lights and a 4 inch for my carbon filter in a 5x10x7 tent. I also have a 14 inch fan circulating the air pointing at the lights. The inside temp is staying between 89-92 degrees with only 20 to 25% humidity with lights on and 65 degrees with lights off, I have my window open 24 hours a day, while the outside temp is 80 degrees, . I just tried putting two 1 litres ice blocks behind both fans to try and cool it down so well see how that works, i have 50 plants in 2 gallon pots that are on there 10th day of VEG. Some of the newer leaves are becoming a bit deformed/small with slight yellowing. I just added nutes and have been watering every 4 days and misting every nite when the lights go off after a 18/6 day. ANY IDEAS!!! Thank you

You can't turn your tent or at least move it away from the wall a bit? Yeah no intake is going to make you have little/no air flow man. I bet your tent is sucked in big time when zipped up for a few. Mine does suck in on itself, but I need that neg. pressure to avoid smell issues.

You may want to look into moving your hut if at all possible. Then use some ducting for at least a passive intake...if that does not cool your temps then indeed get a bigger fan. If they inch sizes dont match up there are reducers you can buy at most hydro stores, or places like Home Depot. For example if you have a 4" port on your hood, but the fan is a 6" port...you would need a 6" to 4" reducer.

If you cant do anything...you may be forced to try the ducts in the ceiling of your tent as intake...but idk how well thats gonna work. OR...may be forced to cut (i know I know..BAD) a new intake (make it clean and resealable somehow of course). I wish I had more time to help you with this today but I am actually on my way out the door.

Good luck man...and indeed get some other opinions. I don't know everything after all.

~Statik~

bosshogg88 said:

I am having the same problems with heat and i am on the 3rd floor as well and am using a 6 inch intake fan with a 6 inch to cool my 2 x 600 watt lights and a 4 inch for my carbon filter in a 5x10x7 tent. I also have a 14 inch fan circulating the air pointing at the lights. The inside temp is staying between 89-92 degrees with only 20 to 25% humidity with lights on and 65 degrees with lights off, I have my window open 24 hours a day, while the outside temp is 80 degrees, . I just tried putting two 1 litres ice blocks behind both fans to try and cool it down so well see how that works, i have 50 plants in 2 gallon pots that are on there 10th day of VEG. Some of the newer leaves are becoming a bit deformed/small with slight yellowing. I just added nutes and have been watering every 4 days and misting every nite when the lights go off after a 18/6 day. ANY IDEAS!!! Thank you

Click to expand...

Swap out your intake fan, for your exhaust fan. You have that backwards.

You want more air flow going OUT than coming IN. I know I am right on that one.

I have a 4 inch for intake, and a 6 inch cooling my light...and a 6 inch attached to my filter. Make sure your filter is rated for the same CFM's (or better) than your exhaust fan as well.

EDIT:

Stop misting. Seriously not needed in this stage of growth unless you have a def cause by lock out and are foliar feeding to help slow the defs.

the fans are an easy fix thnx. but i thought during the VEG stage the plants love to be misted after a long light day?? and also whats the proper humidity levels during this stage, Im growing PK, I thought its suppose to be between 35-60%?? mines 20-25%!!!! bad??

Thanks for the information. I am thinking about cutting a hole at the bottom I think that will greatly help. I hate when things are not perfect so Im sure ill be careful with the hole and to seal the cuts so it doesn't get torn. Unfortunately I keep the tent in a closet, to vent to a light above when was replace with a fan, and Ive tred to move it out but the doors will not close then. I think that an intake should solve this problem.

I have the same problem. My tent is 4 x 2 x 5 and I have 2 6in holes on the sides of the tent at the top. Also I have 3 breather pockets around the bottom of the tent. I am using 4 90w UFO Led lights. My tent is in my closet too. The side top hole I have a 6 in. duct fan venting into a cavity in the wall that goes into the attic. I have a water type fan that I made work IN THE other 6in hole. It blowes in air { kinda like a swamp cooler}. Should I make a hole at the bottom and re run the cool air into the bottom? Ambiant temp in room right now is 77 degrees temp in tent is 85 degrees {with no water at the moment}. I have a thread on another forum that you can see what I am doing. Click HERE.