Carbon Filter help

KlosetKush

KlosetKush

Active Member
So I have a 6" inline fan from terrabloom

https://www.amazon.com/gp/aw/d/B00WW4H8XY/ref=mp_s_a_1_1?ie=UTF8&qid=1518481911&sr=8-1-spons&pi=AC_SX236_SY340_FMwebp_QL65&keywords=terrabloom+inline+duct+fan&psc=1&smid=A3I2VACYSJR5AQ&th=1

And a speed controller from terrabloom as well.

My question is can I use a 4 inch carbon filter with a 4-6 reducer to a 6 inch ducting to my fan and it work efficiently?

I read the max cfm of my fan is 240 and the max cfm for the filter I'm looking at is 240 as well
 
BigHornBuds

BigHornBuds

Well-Known Member
I would send that fan back n get a real one
That booster fan is not going to pull enough air , and there is no way it will pull any where close to 240cfm through a filter.
I don’t think it will pull 240cfm at 10000 feet elevation will zero restrictions.

Get a turbine fan , if your worried about noise , the NuTone 4” is the quietest one I own, but it moves about 100-150cfm and about $200cdn
I have other 4” about $100 about the same cfm’s but twice as loud(they move more air then the Nutones)
 
KlosetKush

KlosetKush

Active Member
BigHornBuds said:
I would send that fan back n get a real one
That booster fan is not going to pull enough air , and there is no way it will pull any where close to 240cfm through a filter.
I don’t think it will pull 240cfm at 10000 feet elevation will zero restrictions.

Get a turbine fan , if your worried about noise , the NuTone 4” is the quietest one I own, but it moves about 100-150cfm and about $200cdn
I have other 4” about $100 about the same cfm’s but twice as loud(they move more air then the Nutones)
Click to expand...

Man this is what I got to work with, I just hope it works well enough
 
McStrats

McStrats

Well-Known Member
I'm a novice grower but I design odor control systems for many industries like plastic extrusion vents where the odors and VOC's are pretty high. Working out your carbon filtration is really just a matter of doing some math. Hopefully you will find this useful.

For carbon to work properly the smelly air needs a certain amount of "dwell time" in the carbon. I see a lot of people use fan systems that are too powerful and the air gets pulled too quickly through the carbon. Get in touch with these guys http://www.generalcarbon.com/ and ask for a carbon pellet that is formulated for cannabis. Potassium permanganate and Coconut Shell are another odor absorption medias works well. There are literally 100's of different carbon formulas for VOC and odor control.

To work out your cfm needed for 10 air changes per hour you multiply your fan systems cfm x 60 and divide by the volume of the space. For example...if a 4" cent' fan has a cfm rating of 187cfm and your space is 6' x 8' x 8' then 187x60=11,200/384 = 29.1 ach.

So..a 4" fan that does 187 cfm running on full speed with an line carbon filter is pulling too fast and the air is not getting adequate "dwell time"...but that same fan running at 1/2 or 1/3 speed is going to be much more effective.
 
KlosetKush

KlosetKush

Active Member
McStrats said:
I'm a novice grower but I design odor control systems for many industries like plastic extrusion vents where the odors and VOC's are pretty high. Working out your carbon filtration is really just a matter of doing some math. Hopefully you will find this useful.

For carbon to work properly the smelly air needs a certain amount of "dwell time" in the carbon. I see a lot of people use fan systems that are too powerful and the air gets pulled too quickly through the carbon. Get in touch with these guys http://www.generalcarbon.com/ and ask for a carbon pellet that is formulated for cannabis. Potassium permanganate and Coconut Shell are another odor absorption medias works well. There are literally 100's of different carbon formulas for VOC and odor control.

To work out your cfm needed for 10 air changes per hour you multiply your fan systems cfm x 60 and divide by the volume of the space. For example...if a 4" cent' fan has a cfm rating of 187cfm and your space is 6' x 8' x 8' then 187x60=11,200/384 = 29.1 ach.

So..a 4" fan that does 187 cfm running on full speed with an line carbon filter is pulling too fast and the air is not getting adequate "dwell time"...but that same fan running at 1/2 or 1/3 speed is going to be much more effective.
Click to expand...

So since I have a speed controller for my fan and can slow the air flow down to give it enough time in the carbon?
 
KlosetKush

KlosetKush

Active Member
McStrats said:
I'm a novice grower but I design odor control systems for many industries like plastic extrusion vents where the odors and VOC's are pretty high. Working out your carbon filtration is really just a matter of doing some math. Hopefully you will find this useful.

For carbon to work properly the smelly air needs a certain amount of "dwell time" in the carbon. I see a lot of people use fan systems that are too powerful and the air gets pulled too quickly through the carbon. Get in touch with these guys http://www.generalcarbon.com/ and ask for a carbon pellet that is formulated for cannabis. Potassium permanganate and Coconut Shell are another odor absorption medias works well. There are literally 100's of different carbon formulas for VOC and odor control.

To work out your cfm needed for 10 air changes per hour you multiply your fan systems cfm x 60 and divide by the volume of the space. For example...if a 4" cent' fan has a cfm rating of 187cfm and your space is 6' x 8' x 8' then 187x60=11,200/384 = 29.1 ach.

So..a 4" fan that does 187 cfm running on full speed with an line carbon filter is pulling too fast and the air is not getting adequate "dwell time"...but that same fan running at 1/2 or 1/3 speed is going to be much more effective.
Click to expand...

My grow space is basically 1x2x4
 
whitebb2727

whitebb2727

Well-Known Member
KlosetKush said:
So I have a 6" inline fan from terrabloom

https://www.amazon.com/gp/aw/d/B00WW4H8XY/ref=mp_s_a_1_1?ie=UTF8&qid=1518481911&sr=8-1-spons&pi=AC_SX236_SY340_FMwebp_QL65&keywords=terrabloom+inline+duct+fan&psc=1&smid=A3I2VACYSJR5AQ&th=1

And a speed controller from terrabloom as well.

My question is can I use a 4 inch carbon filter with a 4-6 reducer to a 6 inch ducting to my fan and it work efficiently?

I read the max cfm of my fan is 240 and the max cfm for the filter I'm looking at is 240 as well
Click to expand...
No. No.

Get an 8 inch if buying a new one. I run a 8 inch filter on 4 inch fan. Always go bigger with filters. Never smaller.
DSC01480.JPG
 
KlosetKush

KlosetKush

Active Member
whitebb2727 said:
No. No.

Get an 8 inch if buying a new one. I run a 8 inch filter on 4 inch fan. Always go bigger with filters. Never smaller.
View attachment 4089079
Click to expand...
I figured that if I went smaller that I could turn my fan down to compensate for noise and the lower cfm rated fan as well as I'm using an inline fan that isn' very powerful as is. That was my though process anyways
 
whitebb2727

whitebb2727

Well-Known Member
KlosetKush said:
I figured that if I went smaller that I could turn my fan down to compensate for noise and the lower cfm rated fan as well as I'm using an inline fan that isn' very powerful as is. That was my though process anyways
Click to expand...
If you keep the fan on low it might work. I have that 8 inch in a 2x4x6
 
McStrats

McStrats

Well-Known Member
KlosetKush said:
So since I have a speed controller for my fan and can slow the air flow down to give it enough time in the carbon?
Click to expand...

You don't need anything bigger than a 4" cent' fan and a speed controller for a 1x2x4 space if you are sizing based on proven science. That air movement is also noisy and adding an 8" fan goes against what you are trying to do in the first place...which is to be as incognito as possible. The only thing an 8" fan does is make your grow space more noticeable.
 
McStrats

McStrats

Well-Known Member
you can also easily DIY a real inline 4" carbon filter that will give you more lbs of absorption media than the cheapo 6" or 8" ones on amazon.

 
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