Venting for odor contol

Greetings Growmies! I am planning ahead for my second grow and want to keep the scent down.

I am growing in a closet in a spare bedroom (junk room) LOL.

Usable floor space is 2’x8’. Height now is 5’ but if I remove the shelf it would be 7’-8’. Good thing about this closet there is existing access to a side T-shaped “attic”. Access point is about 1’ to 3’ from the floor. What would I need?

I just thought that would be an easier solution that cutting a hole in the ceiling.

I appreciate any and all suggestions. Simple and inexpensive preferred of course.

Thank you in advance.


You will need an exhaust fan I’m sure you already have and a carbon filter fitted to that as well and you can take your duct and run it into attic access! If you don’t want to cut a hole into the access panel get a piece of ply wood or even blue board insulation foam cut it into the proper dimensions and use that as the panel while your growing in there.

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@Teffygreenthumb. I have no exhaust or carbon filter this grow. I am starting from scratch. The access is just a framed drywall portion and has never been opened up.

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By my calculations you have 128 square feet in your grow space. I was told by a hvac professional to multiply that by 5 and the is the cfm of the fan you want to put in the area. I think that is high and if you were to multiply by 2 or 3 you would be good. I know as my grow progresses I increase the flow through my tent or odor starts to leak out. I am hyper sensitive to the odor as we have guest that don’t approve. If you are in a sealed room you will need to think about inlet air also.

Inexpensive means different things to different people. What is your budget for your vent system?


In order to have proper ventilation with odor control you will need a exhaust fan and a carbon filter, which can be vented into your attic, me being a residential carpenter a drywall patch especially in a closet is very easy to fix after the fact.
The only way I know of odor control is with a carbon filter and good ventilation, even if you do somehow vent it into your attic (without) exhaust fan the smells will escape your attic vents and you will be smelling it from your driveway!
Now I am a contractor haha and you can’t go clogging or patching attic vents either haha those are what allow fresh air into attic with out those vents your roof would basically be uninsulated!

Is odor a big deal for you? If not I don’t see why putting a small fan or something into attic access to push your closet air into attic wouldn’t be an issue I think that would work but that doesn’t combat the Odor issue if there is one

Edit: there are cheap exhaust fans and carbon filters although the cheaper the carbon filter the more often it needs a change

@bubblehead I really haven’t set a budget. I’ll pay for whatever is adequate for my needs.

I am not worried about it turning on or off based on humidity or temperature - just venting out for odor control. Temp and humidity have been very stable this grow.

The room and closet are not airtight so the intake would probably pull from the house. I want to minimize the scent when people stop by and not give neighbors a snootful. We are legal here but live in a neighborhood with a lot of Karens and Brads.

Wax warmers/incense only cover so much scent inside.



I like what you have suggested! Fan to vent out with a carbon filter. At least the inside of the house won’t have such a scent.

I am also going to hang some carbon pigs…activated carbon hung in pantyhose. Used those in my kids’ gym bags and sport shoes.

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Okay lots of ways to solve this issue. If noise is to be considered I’d look at the fan below. I have one and love it. Even on highest setting it is very quite.

Filters prices are all over the board. I tend to go mid to low range and have been getting several grows out of mine. Mine run 24/7 to help with heat so if you ran yours only in flower you may get more life out of filter. I have this one and it has been working well.

Recently someone recommended a fan like the one below. The only experience I’ve had with fans like this has not been anything to write home about and that is why I upgraded to the fan I have now.

Don’t for get the ducting. I just use duct tape to put mine together and it works fine.

Lmk if you have any other questions.


@Bubblehead. Price looks good. Do you think the fan and filter should be in the closet or attic?

I am sure I could McGyver something to attach them to the wall and not use up floor space. Already did a lot of McGyvering this grow.

That would be personal preference. I have mine in my tent because I don’t have room outside the tent. Sometimes I wish I did so I had more vertical room. You want to pull air from the top.

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My grow room is a closet. It measures about 500 cubic feet (8x8x8). The fan I use plus the carbon filter merely sits on the floor of my grow room. Based on the throughput of my fan, it recirculates the air in my grow room through the carbon filter e very 3 minutes.

Some of our plants are at the stage where odor IS an issue. With the fan/filter running - no problem. My system does not vent outside at all.


@SurferDude. Can you provide the brand name(s) or Amazon links?

Vortex 4" fan (177 cu/ft per minute. Circulatyes all the air about every 3 minutes to scrub the odors.

You might also watch this video: