Serious heat issues. losing faith.

John Dope

New Member
I have a 2.5'x3'x6' flower cab with a 600w HPS and air cooled hood that is ducted to a 171cfm 4" fan that is pulling fresh air into the box from outside. Also there is a 435cfm fan that is pulling air through a 6" home made carbon filter. ALso I have two desk type fans that are at the top of the box angled down to help wth the temps. Not working. With everything on the temps are in the 88-90 range. Lights off they are around 77 but and rh is 40%. How is it so hot in there with all those fans?? I think the carbon filter doesnt have enough holes in it to get the fresh air out. The 171cfm fan brings in fresh air, but the light is heating that air up before the carbon filter can get it out. What do you guys think. please help!

PS: There is a 6" to 4" reducer from the 6"435cfm fan to the The carbon filter which is a piece of 4" pipe about 12" long and capped off. There are about 15 holes drilled in the capped end of the filter, but I don't think it is enough holes.
Re: Serious heat issues... losing faith.

Can you test it without the carbon filter? What is the ambient air temp from you outside air source? Is the air on the exit/exhaust side of the lights ducted out of your grow room/box?

I am running two 600's in a 4x8 tent. I have one fan that pulls outside air to cool the lights. The lights are ducted outside the tent. Nothing else on that system as it is only to cool the lights. I have another fan ducted in pulling outside air in to cool the tent and provide fresh air. One additional fan the exhausts out the top of the tent to evacuate warm air. I am just using 6" 260cfm duct booster fans ($40) and my tempts run about 75-78 degrees. I keep the fans going 24/7 even if the lights are off.
Re: Serious heat issues... losing faith.

I'm a little confused. You said you have a 600w with air cooled hood. Are you pumping air from outside directly thru the hood and back outside?
Re: Serious heat issues... losing faith.

It's 4 times easyier for a fan to pull out the push in. Also I am not a fan of those pc fans. they dont have a real CFM raiting...

I would make all fans suck out. Put a few holes in the bottom of the box to suck in cool aor. Also take all the restrictions off the carbon filter and fan, just place them together then hook to a pie going out.

Also if you have a 45 or 90 degree bend in your pipes your dramaticly cutting the air flow.
Re: Serious heat issues... losing faith.

I think you're going to need to go to 6" inline exhaust fan, 6" ducting and a 6" filter, no reducers.

Reducing from 6" to 4" anywhere in your setup is not going to give you enough flow to handle the heat from that 600w HID.
Re: Serious heat issues... losing faith.

I have determined that I have more than enough "fire power" I just need a new filter now. Going to start over on the box and really dial it in. First few setups were learning experiences. I will check back after install of new filter. Thanks for all the replies!
Try putting the filter on a seperate exhaust line for the cab itself and run the exhaust for the light without the filter. If the flanges on the hood are 6" try to run 6" ducting and the 6" fan on the exhaust for the light. as previously stated and from personal experience reducers ruin any kind of airflow your trying to achieve.
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