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Ventilation: what size of fan you need

Dichoti

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Random mix of Stardawg, APG, and Cherry Bomb.
At 4 x 4 x 7 = 112 cubic feet x 2 = 224 cfm fan

I multiply by 2 for losses due to ducting. The actual losses could be less but it is a rule of thumb that ensures you will have enough power to exhaust at the rate of one air exchange per minute. In your case, 112 cubic feet is the target.

If you have 120 volt power, I recommend something like:
https://www.ebay.com/itm/Strong-CFM-4-6-8-Inch-Inline-Fan-Hydroponics-Exhaust-Fan-Duct-Cooling-Fan/331835934649?epid=1966337412&hash=item4d42f687b9:m:mE3AWU1GhURsauxhYNupdtA

You might also look into a controller like this:
https://www.ebay.com/i/282266838825?chn=ps&dispctrl=1

And here is a filter:
https://www.ebay.com/itm/VIVOSUN-4-6-8-inch-Air-Carbon-Charcoal-Filter-Odor-Control-Scrubber-for-Fan/172810741794?epid=1573556714&hash=item283c52a822:m:mlzuYi1BtTSa7jILbWNP_Yw

Hope that helps.
I dug out the paperwork that came with the fan...
210 Cfm...
So, As long as it's nothing super stanky, I should be good, Right?
 

Unique

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I dug out the paperwork that came with the fan...
210 Cfm...
So, As long as it's nothing super stanky, I should be good, Right?
that size will work for maybe 1-2 plants in a 4x4 tent, but you'll be pretty much maxed on speed router, a 4x4 tent should really have a 6" extraction & scrubber, with speed router, you'll be able keep fan running much lower speed's, so it will not only last longer & be more efficient but will do much better job at clearing the stink....not to mention less noisy, since it can be kept down much more then the other size.
 

Padawan1972

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I dug out the paperwork that came with the fan...
210 Cfm...
So, As long as it's nothing super stanky, I should be good, Right?
Should be fine..however, if you can swing it, I would go up one size with a controller. Just in case of possible problems, heat, smell , tent upgrade.
 

Unique

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Should be fine..however, if you can swing it, I would go up one size with a controller. Just in case of possible problems, heat, smell , tent upgrade.
oh yeah what he has will work, for now. but by no means the best option for a 4x4 tent... I thought the idea of 4x4 tent so can have more plants growing? but that isn't big enough for more then 2 very stinky plants, it would always be maxed out and loud... I just think stepping up to a 6" is much better choice, will be next to silent, work 80% better my 6" is 440cfm...using speed router I Never have go over half throttle..that's with 4+ plants and very stinky ones at that.. no 4" can handle that many plants, it would constantly be maxed it won't last long, tent will be getting severe neg pressure, just lots of bad using under sized extraction. it will work for sure, just not efficiently at all...6" makes many choices in scrubber sizes as well, 4inch does not...
 
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Dichoti

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oh yeah what he has will work, for now. but by no means the best option for a 4x4 tent... I thought the idea of 4x4 tent so can have more plants growing? but that isn't big enough for more then 2 very stinky plants, it would always be maxed out and loud... I just think stepping up to a 6" is much better choice, will be next to silent, work 80% better my 6" is 440cfm...using speed router I Never have go over half throttle..that's with 4+ plants and very stinky ones at that.. no 4" can handle that many plants, it would constantly be maxed it won't last long, tent will be getting severe neg pressure, just lots of bad using under sized extraction. it will work for sure, just not efficiently at all...6" makes many choices in scrubber sizes as well, 4inch does not...
I'm actually only planning on doing one plant at a time until I fully get the hang of it. After I have some experience, and know what NOT to do, I'll move up in fan size and number of plants.
Btw... It's two 24 gallon totes (rdwc of sorts), 1000w el cheapo full spectrum led (feels like you're getting sunburn if you're within 18 inches or so of it), in a 4x4xalmost 7 tent, 4" fan and charcoal filter... This can either go extremely well, and only be needed for meds twice a year, or it'll all go to shit haha
 

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I'm actually only planning on doing one plant at a time until I fully get the hang of it. After I have some experience, and know what NOT to do, I'll move up in fan size and number of plants.
Btw... It's two 24 gallon totes (rdwc of sorts), 1000w el cheapo full spectrum led (feels like you're getting sunburn if you're within 18 inches or so of it), in a 4x4xalmost 7 tent, 4" fan and charcoal filter... This can either go extremely well, and only be needed for meds twice a year, or it'll all go to shit haha
i'm not sure about rdwc, I know there are plenty who use that on here... I use only coco/perlite...about that light I couldn't tell ya for sure.. I think even though it says 1000watts, I think it's really like only 100w-200w at very most, I think they using them "double chip" you probably could of gotten like a meizhi 600w reflector for same cost 130-140$ and that will certainly out-power that 1000w easily...
 

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I'm actually only planning on doing one plant at a time until I fully get the hang of it. After I have some experience, and know what NOT to do, I'll move up in fan size and number of plants.
Btw... It's two 24 gallon totes (rdwc of sorts), 1000w el cheapo full spectrum led (feels like you're getting sunburn if you're within 18 inches or so of it), in a 4x4xalmost 7 tent, 4" fan and charcoal filter... This can either go extremely well, and only be needed for meds twice a year, or it'll all go to shit haha
the only reason I say about not wasting money on a 4" is because for sure you will upgrade, everyone does! that's just how it goes.. at-least your starting with a good tent size, since your running led heat shouldn't be an issue with that 4" anyways, I just can't say for sure how well it will clear the stink...you should make sure have a speed router no matter what, you not want run that at full speed always, it won't last, neither will your tent from all neg pressure...not sure if ya know, but you will have keep some side vents open where the Velcro is, so your able exchange air inside tent, if not providing co2...and you won't need run extraction for a while with led, so then will need a fan blowing in air and still have extraction on timer every what-ever you think is right for air-exchange, there is a calculation you can go by for that..
 

Dichoti

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i'm not sure about rdwc, I know there are plenty who use that on here... I use only coco/perlite...about that light I couldn't tell ya for sure.. I think even though it says 1000watts, I think it's really like only 100w-200w at very most, I think they using them "double chip" you probably could of gotten like a meizhi 600w reflector for same cost 130-140$ and that will certainly out-power that 1000w easily...
The LED uses 10w epileds. I believe they're double chipped, but I'll have to check. I actually only paid $50 for it after seeing that people were bitching about photooxidation. The thing is super bright. I put it in my tent, and turned it on to see if there were any holes or tears in the tent... It looked like there were reddish purple lasers shooting out the vent holes haha
 

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I'm actually only planning on doing one plant at a time until I fully get the hang of it. After I have some experience, and know what NOT to do, I'll move up in fan size and number of plants.
Btw... It's two 24 gallon totes (rdwc of sorts), 1000w el cheapo full spectrum led (feels like you're getting sunburn if you're within 18 inches or so of it), in a 4x4xalmost 7 tent, 4" fan and charcoal filter... This can either go extremely well, and only be needed for meds twice a year, or it'll all go to shit haha
It's only gonna be 180ws so don't expect loads but what u get will be very frosty

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