First Micro Stealth Grow with PC Fan Filter

Discussion in 'Growing Marijuana Indoors' started by Scrumpy1991, Aug 21, 2019.

  1. #1 Scrumpy1991, Aug 21, 2019
    Last edited: Aug 21, 2019
    Hi all!

    First time post here so Ill try and not waffle.
    I'm in week 10 of my first ever indoor stealth grow (you can see more Nirvana Blue Mystic Auto grow journal by Scrumpy - GrowDiaries) and wanted to share it as its late enough that I haven't been arrested or her die, so incase anything I've done helps anyone I'll feel fulfilled.
    I think overall the grow is going well, I know its not perfect but everything is a learning curve so be gentle!

    Background is when starting this project I wanted it to be as stealth I could make it, not because I have to hide from someone, but to see if it was possible as I enjoy making things in my space time.
    Before starting this I know that filtering air and removing the smell would be the most challenging part as I didn't want to use big fans and noisy ducting, so I spent a few hours researching to see if I could find a way of making successful carbon filter utilising a PC Fans.
    I saw a few designs, but there wasn't much in the way of journals explaining its success as the vast majority ended up switching to proper set-ups with inline fans and ducts.
    I know that the pencil holder with tights is popular, but I wanted to see if there could be a mode compact and potentially modular system I could come up with.

    To begin with as the cab is going to be in my home office, I started with an old ikea unit that I no longer needed, simple cupboard with a single door. I decided that as I was going to be using PC Fans, which aren't the most powered things available to start with, let along with the resistance of a filter, that splitting the cab into two sections would allow me too cool the LED light separately, reducing heat in the main grow area.

    I split the level using some MDF cut to the depth and width of the cab, with a perspex sheet stuck over a whole cut in the middle which was the same dimensions as the light. I then sat the MDF on some L-profiles I cut and stuck to the inside of the cab. Sealed all gaps and joints with silicone.
    At the back of this section I cut a 80mm square in the cabinet, which I placed a PC fan into. I then cut a bit off the top of the cupboard door and Im left with a cooled lighting area separate to the grow area.
    The left over space beneath was left to growing.
    On the back of the wall I cut out two 90mm (fan size I had at the time) holes which became my exhaust and carbon filter locations. I cut the bottom of the door like the top so I had air in and out.
    For the filters: I saw the post by Stoned_Stew_UK and the idea of building right off the fan in a modular way stuck with me.
    I had some Artic F9 fans from a previous tinker, these are ok static pressure fans, close to but not as good as Noctura. So if you started from scratch I'd get Noctura every time as static pressure is what you want, and maybe go for 120mm fans as well.
    Anyway, I took myself off to poundland and bought myself some clip-lock containers type things which matched the diameter of my fans. I seaIled the fans to the back of the cab over the holes I cut (externally to save space inside).
    I then proceeded to cut a pot in half leaving me with a rim with the lockable lip, which I stuck around one of the extract holes on the inside. I cut the middle out of one of the lids and stuck some wire mesh over it. i then cut another pot in half and stuck the half with the lip as before, over the mesh. Finally I cut the middle out of another lid and I placed some carbon sheet foam stuff so it sat within the lid but wouldn't come out.
    so I had wall of cabinet>pot with clip ring>lid with clips>mesh>Pot with clip>lid with carbon foam. Within this complicated sounding thing, I had created a void which was encased with mesh or foam, this is where I stuck some activated carbon pellets in.
    As you can see from the pictures, its easier when you see it. The idea is that if I added another layer of wire mesh the whole thing becomes relatable and modular.

    Anyway, I made two of these and didn't really use them for a while. Im growing blue mystic at the time which only had a 'plant' smell so I wasn't really bothered. However a month ago it got to that time and the whole house stank. I took the filters out of the drawer and clipped them to the rings on the back of the cupboard and left it for the night. The next day the smell was not even noticeable, I understand now like many of you m sure that there is no 100% smell proof method if you're not venting outside, but I am confident to say that this is at least 95%, the remaining 5% is what i'd call a planty smell, not one that any nose would instantly recognise as weed.

    I'll admit the airflow is massively reduced as to be expected, but as the cab doesn't get that hot, its not a huge deal for cooling. As for air exchange, I don't even know how to work it out, but its such a small space that I have to just imagine that it is enough (also plant hasn't suffered any notable ill-effects since).
    I think there's some things that I would definitely upgrade/change for the next grow, but I am pretty pleased with the results and I want to share the knowledge that it is possible to build a functioning carbon filter for a small grow, using just PC fans.

    So there it is. I hope its kind of helpful to someone, or anyone!

    Thanks for making it to the end.


    • Like Like x 1
  2. can you put pictures of the connector filter to the fan?
  3. Ive since changed the design so its 2 sets of fans in one. I hope it makes sense. no carbon in this one yet as not needed right now.

    IMG_7405.JPG IMG_7403.JPG IMG_7406.JPG IMG_7401.JPG
  4. Nice job
    • Like Like x 1
  5. The pictures aren't terribly helpful, sorry.

    Also, the 4 fans for the filter are controlled by a fan speed controller up in the light section, as well as another one for the fan light and internal fans.

    Bit too many wires still haha IMG_7411.JPG

    Attached Files:

Share This Page