2x4 Grow Tent Ventilation Question

[IjustSmoke]

Hi, I'm currently waiting for my 2'deep, 4' long and 5' tall tent to arrive. I'm going to be growing 6 autoflowers, and possibly another feminized seed (depending on space). As for lighting, I'm going to be using a 1000watt hps, and a 150 watt hps. My plan for ventilation is a 6" inline fan (rated 200cfm) for intake, and 2 6" inline fans for exhaust. I will connect one of the exhaust fans to my euro reflector. And of course a few circulation fans. Is this enough ventilation??

 

[Becorath]

Not an expert, so wait for another answer, But i would say this should be plenty. Def have the 1000w on the exhaust. You could really do without the 150 in that small of space. it'll just make more heat.

 

[drgreentm]

i will tell you when using a tent you are going to want about the same cfm in and out or it is going to cause some serious negative pressure in there and such the tent up lol, i have 2 tents right now 1 4x8x7 tent for flower with x2 1000w in it and a 740cfm exhaust fan and a 740 cfm intake fan and a ac unit cooling the room temp the tent is in down to 68 and my tent still runs around 80F so initially what you are trying to do would be like me trying to run x4 1000w in my space, its going to be SUPER hot in there. the 1000w for your tent is much to big my friend i would go for a 600w in there and even that is allot of light for that space but would be much more manageable on the heat.

 

[IjustSmoke]

I appreciate the answers, I'm starting to realize the extra cost for cooling a HPS may not be worth it. I figure i could easily replace it with high output cfls. Save my energy bill and heating problems. Does anybody know how many actual usable lumens 1000watt hps produce? I read on a hydro website that they only produce 19,500 usable lumens...

 

[drolove]

tell you what i got the same size tent with a 400 watt hps that runs around 90 degrees being air cooled with a 240 cfm 6 inch fan through a air cooled light hood and the tent has a 80 cfm inake. i would think 1000 watts in that space will be WAY too hot even with a lot of ventilation. and if you can make it work the extra light wont be needed. and im pretty sure a 1000 watt produces way more lumens than that

 

[drgreentm]

I appreciate the answers, I'm starting to realize the extra cost for cooling a HPS may not be worth it. I figure i could easily replace it with high output cfls. Save my energy bill and heating problems. Does anybody know how many actual usable lumens 1000watt hps produce? I read on a hydro website that they only produce 19,500 usable lumens...

1000w is a great light, cant listen to some of the crap floating around the net sometimes. my 1000w's stay to the ceiling of my 7' tent and never go up or down throughout flower and my plants dont stretch for the lights like they would with say a 400w. these things put some serious light down to the floor!! they are great lights to have just not in your particular space.

here is a link to bigstuff's grow https://www.rollitup.org/hydroponics-aeroponics/514266-2x4-food-drain-stealth-grow.html he is growing in a tent similar to the size of yours i believe and runs a 600w i think (you will have to ask him to confirm this) and he is having great results. just change out that 1000 for a 600-400 and you should have better luck with cooling it down easier.

think of it in terms of watts per foot sq, with a 1000w you are at 125w per sq foot (way overkill) with a 600w you are at 75w per square foot (still allot) and with a 400w you are sitting right at 50w per square foot (right at optimum) my 1000 in a 4x8 are at 62.5w per square foot and they are a little of a challenge to cool. i have the air completely exchanging about 4x in a min with 68f air and it still creeps up to 80f in the tent.