2 x 4 Lighting for Flowering with QB Elite v2

i have a 10" 1k cfm hyper fan for my 10x10 and its been doing well for me. Goes pretty close with what random is suggesting.
I have it going into a 5 foot tall can filter though lol. Im trying to prevent any smell from coming out of the basement and this setup has done it well just finished week 7 of flower. Tent smells so strong a good deep breath will sting your nose but you cant tell I grow in the house.

Randomblame said:

You need a bigger one for a 4x 5' area (at least in summer) even if you use no bath fan with hepa filter in the bottom hole. You need very little underpressure but in no case a vacuum, lol! And you only need underpressure inside the tent if its important to eliminate the smell. If its not important you don't need underpressure. But for a 4x 4' you need at least a 230ft³/5-6" exaust and 80-100ft³/4" on the bottom. Believe me, it makes sense and as long as you use a bigger exaust you still get a little underpressure which you can see on the tent walls. They should be slightly curved inwards but not too much.

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Sorry perhaps I said that wrong. I use a hepa filter FROM a vacuum, not to create a vacuum. Just to keep shit out of there. The fan is small but it can totally replace the air in a few minutes.

Randomblame said:

You need a bigger one for a 4x 5' area (at least in summer) even if you use no bath fan with hepa filter in the bottom hole. You need very little underpressure but in no case a vacuum, lol! And you only need underpressure inside the tent if its important to eliminate the smell. If its not important you don't need underpressure. But for a 4x 4' you need at least a 230ft³/5-6" exaust and 80-100ft³/4" on the bottom. Believe me, it makes sense and as long as you use a bigger exaust you still get a little underpressure which you can see on the tent walls. They should be slightly curved inwards but not too much.

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I’m not using a tent either. I have a grow room built over a tub we don’t use. The tub is too big for our hot water tank. We didn’t install it, it was here when we bought the place. I made a table and lined it in EPDM pond liner, panda poly all around. Mounted a Fluence Spydr x in there ( just fits ) and the light controller outside, and a inkbird heat/ humidity controller. The table has a slight tilt from back to front and has a drain in it where a hose is connected. I can drain to tub or drain to save and test by aiming hose where I choose. I just built the room so it’s a work in progress. I want to mount a 4” can air and filter in it. My neighbour has a small humidifier I can have. As for the heat side of the controller I will just connect that to the ventilation fan. Should work? If not I will shut it down in the summer and move my grow into the greenhouse.

Randomblame said:

Sorry, brother! But they don't get hot, lol! At least not hotter like other LED's....

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Like I wrote, they get hotter than my 800 boards (compare to 3x288s). They get hot enough that after I stuck a filter on my main air mover that it got to 35.5C, so without proper ventilation, expect an overheating issue. I didn't say that its impossible to grow in a tent, but its hotter than 288/302 boards get.

I can touch any of my heatsinks while the light is on, but I would dare do that with (for long) on a 96. At 240W, they get hot. At 300W, the 800, not so bad (still needs ventilation).

btw, my avatar is an overlay of a 288 and a 96 spectra.

trojanvirus said:

Like I wrote, they get hotter than my 800 boards (compare to 3x288s). They get hot enough that after I stuck a filter on my main air mover that it got to 35.5C, so without proper ventilation, expect an overheating issue. I didn't say that its impossible to grow in a tent, but its hotter than 288/302 boards get.

I can touch any of my heatsinks while the light is on, but I would dare do that with (for long) on a 96. At 240W, they get hot. At 300W, the 800, not so bad (still needs ventilation).

btw, my avatar is an overlay of a 288 and a 96 spectra.

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Yeah, QB96 is a lot smaller and can running at a higher wattage. But if you dimm them down to the exact same wattage like the 288's and put each in its own 4x 4' tent you would get the same ambient temps even when the QB96 heat sinks feel hotter. You have simply used more watts compared to the 800 board and for this reason you get higher ambient temps. Surface area is all what matters when it comes to LED cooling and such a huge 800's boards has much more cooling surface and therefor they don't get really hot.

BTW, I like your avatar, bro!
Seems you has thought about what to use! Not just a silly smiley like me...

Randomblame said:

Yeah, QB96 is a lot smaller and can running at a higher wattage. But if you dimm them down to the exact same wattage like the 288's and put each in its own 4x 4' tent you would get the same ambient temps even when the QB96 heat sinks feel hotter. You have simply used more watts compared to the 800 board and for this reason you get higher ambient temps. Surface area is all what matters when it comes to LED cooling and such a huge 800's boards has much more cooling surface and therefor they don't get really hot.

BTW, I like your avatar, bro!
Seems you has thought about what to use! Not just a silly smiley like me...

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Do you have a recommendation for distance from the qb96 elite v2 to the canopy for the veg and flowering stages?