Tent ventilation when using HID

Hey all, I was wondering, how do some of you ventilate your grow area while running a closed/forced air exhaust system for the lighting. How are air exchanges done with closed hood systems?

I have two carbon filter systems running next to my 630 W

and 2 down low

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I see, so you’re running almost a plenum exhaust style using the open hood? @Hogmaster

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VIVOSUN 440 CFM 6" Inline Duct Fan with 6" Carbon Filter Odor Control with Australia Virgin Charcoal

@Thelaughingwolf there are many sizes and styles I also have just carbon filters with in-line fans on the end

Ok, now I see what ya did. The vertical duct to the floor is the inlet, and the two filters and fans up high. How are temps at the canopy when at closest distance?
And thanks for the help already!

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Useful tip: Spray paint the inside of aluminum ducts black to prevent light reflection. Otherwise they transmit a lot of light and can ruin your flowering dark time. Especially if your exhaust duct is short and goes right to an outside window. Of course, if you have a filter in there you don’t need to do this.

I just suck room air in near the bottom with a little cardboard light lock, painted black inside. The exhaust at the top is where the fan is. If you can suck exhaust air through your light(s), so much the better. If you have a fan running for air circulation, heat sinks will warm up the whole chamber unless you devise a way to suck exhaust air through them.

@Hogmaster has you covered i run the same light set up as he does and do the same tbing have my filter set just above the light to pull heat in i also use a floor fan to blow cool air at hood to prevent heat frim building up in the first place
I run that exhaust tube over by my portable ac that i keep set fir 80 degrees doesnt run much at all in winter lol
I then have a second carbon filter and exhaust fan that exhausts out of my grow room to outside
I have a third fan i use as a intake fan ti provide fresh air from the basement itself
Just a few other options for you
Cooled hood work well also if you wanted to invest in them

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@Hogmaster is the man. I’m thinking of using an enclosed cooling hood only because my space is only 6.5 feet tall, so I want to be careful not to burn plants when they become taller and figured the glass would help diissapate some of that heat. I’m leaning more towards using a 1000w hid system and running it at 60% for veg and 100% for flower.


What they’re doing is a little different than what you’re talking about. I think in your case the most common configuration is running them inline. Air comes through filter and is ran through duct to first light, then through duct to the second light, then exhausted.

You just need to make sure that your fan and filter are sized big enough to move enough air. There will be quite a bit of loss on a system like that.

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