Intake/outake fans with and carbon filters

Okay, so Im a little confused on how this should be.

Do intake and outtake fans need to be at the same speed? Does a carbon filter fan need to be faster than the intake and outtake?

well a carbon filter sits at the end of your lights and air is just sucked thru it and it takes away the smell. or you can just have a outtake with ducting going str8 to your carbon filter and it will do the same thing but better

and its going to be hard to get htem to go at the same speed you want to recirculate the air often so you want sum gud suction if your running more than 3 lights i would go with a 8 inch exhaust fan. and central air with a fan in the door way of your grow area works great

you dont need an intake fan. al you need is a conduit leading to where ever your source of in coming air is.

since youre using a carbon filter ill assume youll want to create a negative air pressure in your grow space to effectively "suck" all the air with pot scent thru the filter

if you have to bring cool air in to the room for heat reasons then yes youll need to ensure that your exhaust fan is big enough to maintain a negative air pressure...a positive air pressure would defeat the purpose of using a carbon filter

Allow me to jump in this thread but I also have questions regarding this; I plan to use a cabin in side a linen closet and the top part of the cabin will have an out take duct from the cabin to the ceiling to the attic, helped along with a fan of course to pull the air out , my quesiton is would it be better to have the filter before the fan or after the fan...

like this: smell and air ------------ > Fan -------------> Filter ------------> Attic

or

like this: smell and air --------------------> filter ------------------>fan----------->Attic

you want to have the filter as close to the source of the smell as possible, actually including it inside the grow space if you have the room would be ideal...but if not then the closet place you can fit it..... bare in mind that carbon filters weigh a lot, mine is about 25lbs,so there is that to consider

Duder1984 said:

you dont need an intake fan. al you need is a conduit leading to where ever your source of in coming air is.

since youre using a carbon filter ill assume youll want to create a negative air pressure in your grow space to effectively "suck" all the air with pot scent thru the filter

if you have to bring cool air in to the room for heat reasons then yes youll need to ensure that your exhaust fan is big enough to maintain a negative air pressure...a positive air pressure would defeat the purpose of using a carbon filter

Click to expand...

+1, all the advice you need

What if you have a sealed room an you clean your air with a carbon filter and pump it back into the room?

Pumping c02 into the room and wont want it to escape

Negative air pressure would mean that the fan/air speed being used to pull the air out must be stronger than the air speed coming in correct?

Wow carbon filters are heavy! I did not know that.... would there be a "mini" solution to say only using it on one plant? I don't think there should be a need for such a big filter for one plant? Although if it means getting rid of the smell then I guess it would be worth it. My issue is I have very limited space ( 1.5 ft x 2.2 ft x 8 ft) horizontally so having it inside the cabin would be a hassle and take up a lot of space...any suggestions?

Mattman- I feel like The exhaust needs to be stronger than the intake. duder1984 is right in about negative pressure. I persoanlly have 2 exhaust fans. This allows me to run the small fan 24/7 and maintain a negative pressure 24 hours a day. I run my ventilation system to cool my room. I have 2 fans blowing in an 2 sucking out with carbon filters. I took the time to filter the intake as well as adjust everything to make sure that my pressures inside are always negative. I like having intake fans and would recommend it, just keep a negative pressure to control smell

Awnox- you want filter>fan>attic

Heathro- You would want to use what people refer to as a scrubber. a fan with a charcoal filter taking air through the filter and putting it right back into the room

Thx for responses will add rep when I get some freetime

Heathro said:

What if you have a sealed room an you clean your air with a carbon filter and pump it back into the room?

Pumping c02 into the room and wont want it to escape

Click to expand...

Ah ok, this is actually quite a challenge.

Since you do not need to have an external air intake, you will want to place the carbon filter as high as you can and use the smallest fan possible while still creating a negative air pressure. You will want to direct your co2 to drain al the lowest point in the room, and since co2 is heavier than air it will fill up the air at the bottom of the room while slowly being sucked out the top.

If i were you i would time my co2 injections so that first the exhaust fan shuts off, the co2 turns on and stays on for about an hour or so...how ever long you can manage to keep it off without the smell becoming too much of a problem. You will also want to shut off any air circulation fan for maybe the first 30 minutes of co2 injection, not too long tho because u dont wanna burn leaf tips and raise the temps too much...remember hotter temps, more smell.

Basically you will think of your carbon filter and exhaust as only providing scent removable, not a component of the air circulation since your co2 injection defeats the need for external intake and exhaust.

EDIT: The other user is right about the recirculating fan, that will eliminate the need for an exhaust. though be careful as I know of people who have experienced problems with their grow room having a natural positive air pressure, or negative most of the time but suddenly goes positive when someone opens the front door, safest best is the system i just described above but if you are in an air pressure neutral environment like a basement then you might be able to get away with just recirculating the air in the room through an activated carbon filter.

AWnox said:

Negative air pressure would mean that the fan/air speed being used to pull the air out must be stronger than the air speed coming in correct?

Click to expand...

correct

AWnox said:

Wow carbon filters are heavy! I did not know that.... would there be a "mini" solution to say only using it on one plant? I don't think there should be a need for such a big filter for one plant? Although if it means getting rid of the smell then I guess it would be worth it. My issue is I have very limited space ( 1.5 ft x 2.2 ft x 8 ft) horizontally so having it inside the cabin would be a hassle and take up a lot of space...any suggestions?

Click to expand...

Check on a few websites (type "activated carbon filter" in search que and look at the only hydroponics store results) the one i use is for a 4x4 space...you probably will be able to get away with the smallest possible filter for such a limited space. You might wanna look into ONA gell as a possible smell solution, it definitely works and is a very powerful deodorant and cheap...some people claim it takes all the smell and taste in the buds, but i would be skeptical of such claims...personally i havent used it but i hear good things.