4x8 tent ventilation

I have 3 friends that all do ventilation differently, and they all disagree with one another. I have a 4x8 tent. How should I ventilate with 2 600w cooled hoods? 1 inline fan, 2, 3? Already got my carbon filter. Also have a shitty booster fan. The most efficient way I've seen so far is having the carbon filter outside the tent along with an inline fan, blowing directly into the filter. An aerial drawn view of a setup would help a lot

Theres several methods but like your friends, the opinion vary. Just find a setup that works with you and stick too it.

I would run a straight line. Carbon filter -> Light 1 -> light 2 -> out of tent. Where you put the fan in that line really doesn't matter. If you don't have space in the tent or don't care about routing hot air post filter you can run it Light 1 -> light 2 -> out of tent to filter. If you run it like this I would advise placing the fan right over the filter.

These ways you get max airflow through each hood, negative pressure, and only need to bother with a single fan.

Gastanker said:

I would run a straight line. Carbon filter -> Light 1 -> light 2 -> out of tent. Where you put the fan in that line really doesn't matter. If you don't have space in the tent or don't care about routing hot air post filter you can run it Light 1 -> light 2 -> out of tent to filter. If you run it like this I would advise placing the fan right over the filter.

These ways you get max airflow through each hood, negative pressure, and only need to bother with a single fan.

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Fans need to sux not blow. so yes it matters, if you have a filter you need to sux threw the filer not blow threw the filter.. and the filter need to be were the air needs to be filtered.. inside the grow not outside.

That's nuts because my fan sucks and blows... Sucks in one side and blows out the other...

I would agree that it is better to suck through the filter first as you'll keep your fan internals nice and clean but works both ways and either way the air will be equally filtered. If you have no leaks in your ducting and negative pressure no air from the tent is going to escape without passing through the filter.

always use the suction side of the fan to pull air through your lights not push air through them, this makes a big difference. as for the carbon filter, i have ran both ways and both work but i like to run them at the end of the suction side of my lights inside the tent. i have a 4x8 tent with x2 1k's in it and i cool it with x2 inline fans of the same rating one to extract hot air out from my lights and one to pump cold air in from the room at the same rate and for a good reason. using 1 fan to pull air out in a tent causes the tent to suck up and drag down the fan so the addition of a fan of equal or greater cfm equalizes the neg pressure of the tent. i have a carbon filter on both fans (in and out air) here is a pic of the fans, dont really have any good pics of the inside of the tent but here is one i have you can kinda see the carbon filter back there and it has a piece of ducting connecting to the right side light.

pic1 is of the 2 fans the lower fan is putting air in the upper is taking it out
pic2 is of the exhaust fan you can see i remove the hot air from the room completely this is the only way to do it as the lights will heat the room quick
pic3 is of the intake with a scrubber
pic4 is of the lights you can kinda see the scrubber back there

here is a top view of my tent ventilation.


notice the exhaust is being taken out of the room the tent is in, i highly advise against venting into the room the tent is in especially with x2 600w unless your room the tent is sitting in is going to be huge. those lights will heat my 12x12 room quick and would cause heat problems. my 2 1k's are another monster but with a 8500btu ac in the mix of this setup it works great.

im new to this which is why im going to ask a stupid question here. Do you actually need ventilation. i know i know, but in my tent its 81 degrees without any fans so its perfect so would you need to put fans in

if you can get away with it then go for it. 81 is a bit on the hot side imo just keep a eye on things like humidity because moist things in enclosed spaces=powdery mildew. without ventilation (depending on your situation) a de-humidifier may be necessarily.

Thanks guys, this really helps

drgreentm said:

if you can get away with it then go for it. 81 is a bit on the hot side imo just keep a eye on things like humidity because moist things in enclosed spaces=powdery mildew. without ventilation (depending on your situation) a de-humidifier may be necessarily.

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Even if you don't use an exhaust fan, you should still have a fan clipped to the inside of the tent just to move the air around... no?

bigben69 said:

im new to this which is why im going to ask a stupid question here. Do you actually need ventilation. i know i know, but in my tent its 81 degrees without any fans so its perfect so would you need to put fans in

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Air exchange to keep co2 levels at a reasonable level. Plants need co2 so unless its supplemented it diminishes quickly and so does the growth rate and life expectancy of the plants.
Bud rot is highly likely without good air movement within the tent/grow room. Nobody wants that to happen. Even chuck Norris is afraid of bud rot

If these guys haven't figured it out in the last 5 years. The last 2 post probably won't help much.

lol.

How's this get picked up off the scrap heap?

bigben69 said:

im new to this which is why im going to ask a stupid question here. Do you actually need ventilation. i know i know, but in my tent its 81 degrees without any fans so its perfect so would you need to put fans in

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Plants need CO2 to grow and can quickly use up the CO2 in a room with 0 air exchange

Yeah this is a post from way back!

I have my carbon filter in tent fan hooked directly too it to suck air through it and it blows that air through the 2 1000w HPS lamps and out of the tent, i also have an intake fan that is pushing cool air into the tent, my tent stays at 81degrees at its hottes point and works great, i have zero exterior smell from my tent.

tpc_mikey said:

I have my carbon filter in tent fan hooked directly too it to suck air through it and it blows that air through the 2 1000w HPS lamps and out of the tent, i also have an intake fan that is pushing cool air into the tent, my tent stays at 81degrees at its hottes point and works great, i have zero exterior smell from my tent.View attachment 3998416

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Venting it out of the tent is only part of equation. If exhaust is not expelled outside the house it's still going to run short on CO2 you'll quickly use the CO2 in the house. Without pushing it out of the house you're not doing much more than not venting at all. Unless the windows are open and the wind is naturally bringing in fresh air.

goldberg71b said:

Venting it out of the tent is only part of equation. If exhaust is not expelled outside the house it's still going to run short on CO2 you'll quickly use the CO2 in the house. Without pushing it out of the house you're not doing much more than not venting at all. Unless the windows are open and the wind is naturally bringing in fresh air.

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yes, you are correct i have a window a/c that pushs fresh air in and also have a c02 tank and regulator

tpc_mikey said:

yes, you are correct i have a window a/c that pushs fresh air in and also have a c02 tank and regulator

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That's another way to handle it. Most ppl with tents don't run CO2 that's why I didn't mention it.

theres usually more than 1 way to skin a cat. But the cat still gets skinned lol