Dirtbag
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A bigger fan yes, but not as powerful as an inline fan, I'm talking about using an axial fan on the intake. And you dont need a 25cfm fan, but you need a fan that can pull at least 25 actual cfm after calculating for ducting and filter losses. The filter and ductwork will greatly slow down the actual amount of air being moved. A 4" inline fan dialed down to 50% worked well for me as an exhaust in a 3x3 for a while, and that was with a passive 8" intake, in other words, no intake fan.bigger fan on the intake than the exhaust?
so if my tent is 54 cubic feet and I can use 2 mins to change it, I only need a 25cfm fan? that seems way too low. im super confused and backwards now.
I blow the intake air directly between the lights and the top of the plants where the most heat is trapped. Then I draw this moderate temperature air from above the canopy and duct it below the plants using a seperate small fan. Works really well at keeping the whole room an even temp, and keeps all the leaves moving gently which increases gas exchange around the lower leaves.
A bigger fan yes, but not as powerful as an inline fan, I'm talking about using an axial fan on the intake. And you dont need a 25cfm fan, but you need a fan that can pull at least 25 actual cfm after calculating for ducting and filter losses. The filter and ductwork will greatly slow down the actual amount of air being moved. A 4" inline fan dialed down to 50% worked well for me as an exhaust in a 3x3 for a while, and that was with a passive 8" intake, in other words, no intake fan.
And yeah I'd use a bigger intake size UNLESS you are powering the intake with an equal size fan as the outtake, with similar airflow loss from filters on each fan.
A 4" inline exhaust with a 6" axial intake will allow the tent to vent without sucking in the walls in too crazy.
ok this has me wondering... isnt the air just doing one big loop and staying stale? where does your fresh air come from?
hmm interesting. I need to get this figured out asap so I know what size filter to order so I can order it and get it here ASAP too!!!
im trying to have the tent air and light tight, with all my air being provided via inline fans. and then a few small fans inside just moving air around the canopy and between leaves.
I was thinking the plants raised on a mesh grating about 8" off the ground.
4" inline fan on the bottom with a Y connection so I can split it into two and have it lightly blowing under my mesh grating, aimed upwards on all 4 plants.
then the 6" hung up top with the 6" carbon filter also inside the tent. the exhaust would be stronger causing a negative pressure and no air would ever escape the tent. any cracks in the tent would be sucking in air due to the giant exhaust.
or am I all wrong?
I may have missed if you said it. But do you need a carbon filter? is smell going to be an issue? You only need a carbon filter for the smell. Again if i missed you say that i apologize.then the 6" hung up top with the 6" carbon filter also inside the tent. the exhaust would be stronger causing a negative pressure and no air would ever escape the tent. any cracks in the tent would be sucking in air due to the giant exhaust.
or am I all wrong?
I may have missed if you said it. But do you need a carbon filter? is smell going to be an issue? You only need a carbon filter for the smell. Again if i missed you say that i apologize.
An you need to vent the stale air somewhere and bring in at least some fresh air from outside. Otherwise you need a source of Co2 and dehumidifiers, AC etc...
Never heard this term before but i love it.most people bring air into the tent from a lung room
You arent wrong, but it's a balance. Too much negative pressure and the walls of the tent will get sucked in hard, reducing the space to grow in. Properly balanced, it should be almost neutral, with very slight negative pressure.
I totally agree, it's only for folks trying to prevent smell from escaping. Positive pressure is better in every way imho. But only if you're runnin dank filters on the intake like that lol. Pressurization with filtered air keeps bugs and other spores and shit out of the garden.Never heard this term before but i love it.
I prefer positive pressure. but its a preference for what you are going for. In my case its how i designed the system. the positive pressure allows me to overcome the pressure drop from the filters venting back into the cavity between the filters and the inlet fan. allowing the fans to run more efficient. But thats all in the design. 99% of people are not going to worry about those things. because they are not going to try running merv 13-15 filters for a single tent. But to a standard inline/exhaust setup. For sure.
its a tent in a little corner pocket of a giant basement... im going to be venting into the basement and also taking air from the basement too.... the intake and exhaust holes are actually kind of close together. is this going to be a huge problem?
Good advice. Has the same effect as running a fan dialed down with a speed control. I use a 10" with a 10" filter, but the fan is dialed way down to keep it quiet, so it draws air slower through the filter. Also let's me get away with a 10" passive intake considering its flowing at half speed and the filter losses etc.To add on to dirtbags comment. The good news about doing it in a basement is you tend to have a floor drain. For me im emptying 2 tanks 3x a day right now. Cause its in a house like everywhere in the house. But in a basement you can just get one with a hose connection for draining and you can let it run for ever.
Its most likely my genetics. But i can barely smell it. But im told im high all the time and unless its skunk or a catchy terp. i dont smell it. But if its a concern 100% get a filter. Im also of the mindset go 1 size filter up and attach to it. IDC what size hose you use. Its about surface area. will make for greater efficiency. So if you want a 6" fan get a 8" carbon filter. Thats just my recommendation.
You can have too small of a carbon filter but not really too big.
That's a lot of air exchange, possibly too much. You want to aim to fully change the air once every 2-5 mins.
Personally I'd run a 4" inline fan with a speed controller on the exhaust and a 6" axial fan on the intake, or if you are filtering the intake you could just run a second 4" inline with speed controller on the intake end as well. That would be closer to ideal, and you could use the speed controllers to balance the pressure in the tent.
3x per minute max turnover with controller to turn down is standard to keep tents cool passively.
And 4x size intake to exhaust hole.
3 times a min? That's a lot of air exchange.. I always had the "once every 2-5 min" in my head but I could be wrong.
bigger fan on the intake than the exhaust?
so if my tent is 54 cubic feet and I can use 2 mins to change it, I only need a 25cfm fan? that seems way too low. im super confused and backwards now.
Growing properly is a time and money commitment. Thousand$ for sure. And you will have bad crops, you'll have crops that make you want to quit. I've seen people have bad YEARS that they eventually crawled out of.damn, this is getting complicated and really taking the fun out of growing it. its become a full time job and requiring thousands in never ending random shit for 4 puny, struggling little plants... got me really debating how far I want to move forward with this now.
damn, this is getting complicated and really taking the fun out of growing it. its become a full time job and requiring thousands in never ending random shit for 4 puny, struggling little plants... got me really debating how far I want to move forward with this now.
6" inline fan is kinda overkill for a 3x3 tent no? A 4" fan is almost overkill, even run passively.Its actually simple and can be done passive with just the 6” fan exhaust likely. Need cool lightproof intake in low to the floor. Bent and black foam or stocking covered duct through the lower socks works great. And exhaust high and out of the building or at least the room. With 3x per minute exhaust i kept my old 4x4 about 5-6 degrees above room intake temp. Basically 72 toom temp. 77 flowering temp under a 600 w air cooled glass enclosed lamp with a carbon filter.
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