Carbon filters, Better to push air through, or draw from?

Discussion in 'Growing Marijuana Indoors' started by MDxx, Feb 10, 2010.

  1. #21 hiesman, Feb 11, 2010
    Last edited by a moderator: Feb 11, 2010
    I use "carbon bags." I situate them in the ducting so that my second fan blows the "old" air through the bags of carbon... the extra === is just the ducting leading outside of the house. Do i need to get any further in detail for you to get it without disrespecting me? Use your imagination. I'm not here to explain all the details to you.

    Hey kid, I'm not trying to step on anyones toes with the scale of my operations but I do believe you were trying to trump me with your grow tent way of thinking

    "what do you think the holes in the grow tents are for?" and "any presence of ducting means your room isn't air tight"

    makes it sound like u are trying to trump my advice and label it useless. which is quite rude. I simply put my two cents on the subject and you attacked my info... its only right that i defend myself. I know that you couldn't be on the same level/ scale as me considering your "grow tent" logic. I understand you have a great deal of ventilation knowledge and exp and i can tell you do by your talk of negative and positive pressure, etc.

    show me some respect and you'll get the same. you cant see me eye to eye because your behind a keyboard and its easy for you youngsters to reach a confrontation.

    I have read all your other posts on this thread. You seem like a cool kid. I'd rather learn than teach.

    Your Friend Hiesman

    edit: oh yea and apology accepted my man.
     
  2. Hell yeah. Do your thing man. How long/harvests have you been at it?
     
  3. and I 'LOLed" at the 9 trillion plants shot... very funny man, made my day. That reminds me of my youngest brother, def something he would say.
     
  4. Ah maybe i should have stated the small pc fan was to pump cooler air into the room bringing down the temp from the previous 88*f which had me concerned. I'll be using a "can" style filter which will simply pass air though a tube about 1 foot long 3'' wide full of carbon with connections on both ends for an intake and outake so i can place it anywhere along my ducting line as long as the exhaust vent is sealed well. Ill connect my fan between the hps hood and right before the can which will be close to the exhaust vent pumping air directly out of the room.

    Thanks for all the replies and info dispite all the hostility floating around, feel free to highjack this thread and continue discussion if you wish.
     

  5. Cheers dude!! :D
     
  6. #26 soapman, Mar 11, 2010
    Last edited by a moderator: Mar 11, 2010


    Consider this thread hijacked, R E V I V A L...

    Anyway, I would like to see some pics posted up with some people carbon setup reversed. Outside their grow space, I'm thinking about moving my filter to the exhaust side. I've done my research about it and pretty much carbon filters can be used on the intake side or exhaust side and still be effective.

    It seems like my fan HAS to be on full blast to maintain any kind of good temp range, not that I have a problem with this or anything but the guy at the hydro shop was trying to explain to me that my setup was using my filter very inefficiently. He said it's only scrubbing air through the front most part of the filter. I kind of believe him now too, it takes a lot of force to suck a decent amount of air through a scrubber and my fan is mounted in the attic and there's about 5 maybe 6ft of ducting before it even reaches my grow room than the 5ft of ducting to get to the light and another 4ft of ducting to get from the light to the scrubber. I have two booster fans installed to assist with moving air around, which they do seem to be helping for the time being, I'd rather do without them personally.

    exhausting air out roof======inline fan=====+====air cooled light=====+===Carbon filter.

    That's how mine is setup right now, the = meaning ducting (obviously) and the + meaning 6" duct boosters. I ran a lot of ducting I used up all of the 25ft I bought and used all of it. I didn't expect, but I had to account for raising and lowering the light.

    Now I figure there are two solutions to this situation. I can leave things the way that they are as there isn't a REAL problem here except that my fan has to be on full blast or close to. Which again, I'm okay with that, I plan on replacing the fan with a nicer vortex sometime down the road anyway. My whole goal is to have more air being pulled through that scrubber. As I don't really now how well it's working, seems good I can feel air being pulled through and what not. I didn't seem to have any smell problems with my last grow using the same setup just without the duct boosters, except the smell that was all around my house it was never outside just inside, very noticable when the fan and light turned off. I'm just thinking the carbon filter is out of it's efficency zone and always has been, I'd like to correct that if possible.

    The other solution would be moving the carbon filter to the exhaust side with the inline fan in the attic, and just leaving one end of my light open so it will pull air through and push into the filter. In order to keep dust and debris to a minimum (as miniumum as I can) I'd put one of those cheap-o air intake style filters on the open end of the light so it will filter out the stuff that I don't want in there, carbon filter will deal with the small as air gets pushed in there.

    Opinions?:confused:
     
  7. WOW why is this even a conversation let alone a 2 page thread lol. Look at how real carbon filters work aka the ones you buy not make. the fan pulls the air through the filter and pumps it into the venting which then goes whereever you put it, im not sure why this is even a debate. This is my carbon filter for a room 12 by 10 Imageshack - 1000204a.jpg and thats how that works.
     
  8. #28 soapman, Mar 11, 2010
    Last edited by a moderator: Mar 11, 2010


    But why? Can you explain to me why you use your filter the way that you do? It looks like you got a whole room there or at least a walk in closet which would explain most of it, you have space to run a setup like that.

    I don't have that...yet. I'm stock with a pretty small closet for the time being, 4x2x8 to be exact therefore my setup has to be a certain way. And if I can use my fan more efficiently by putting my scrubber on the exhaust side than that works too doesn't it?
     
  9. Uh obviously your scrubber would be smaller but its all the same concept. Why would u ever push the air out of the scrubber its just illogical and defeats half the point of the venting purpose (heat removal) not to mention the fan you use will die twice as fast. If you have small room use a small filter and do the same thing as i did. Look up any legit carbon filter company all their filters will tell you to use it like that, if you cant vent you still pull the air through the filter not out it still has the same effect that way compared to pushing it out the filter. I'm just so confused as to why you would do it backwards? Got pics? Maybe give me more details, but no matter what this is the way to do it whether you vent the new air out of the house or keep it pumping inside. And im not sure who said pumping the ODOR out of the house, the whole point of a scrubber is to remove odor your not pumpin the smell out your removing it the air that comes out of it smells so damn clean its redonkulous.
     
  10. #30 soapman, Mar 11, 2010
    Last edited by a moderator: Mar 11, 2010
  11. seems like it would be better to have the air sucked into filter 1st, and pushed out through ducting......seems like the fan would have to work harder the other way by pushing it through filter and ducting.....
     


  12. See I don't think so. In my mind my inline fans exhaust side pushes enough air that it will push air out of the filter, just take off the pre-filter since you don't need it anymore and I bet it works just as well. The only downside to it is you have to make sure there aren't any rips in your ducting otherwise smell will leak.

    I hear a lot of this is the way to do it, or it was meant to be sucked through. But can any of you that think this actually explain why it is that this is the only way they can be used? Has anybody ever actually asked a carbon filter company and got their opinion.
     
  13. Sigh, why would a carbon filter company make videos of it only done 1 way, Ill take their word on it. I didnt say it can only be used this way I said this is the proper way to use one, you can drive your car in reverse to get to places but I wouldnt recommend that either.
     
  14. Just to chime in, I agree that an entire room is the way to go, but tents make excellent area dividers/isolators as far as photo-periods and atmospheres go. The setup I'm about to present is intended for a CGE that is a CO2 enriched, LED lit tent(s) that vents into a room that is kept at a low negative pressure with the room having an independently filtered exhaust to the house or outside(air flow pulled through).


    Grow tent 6" intake==> Inline 180 CFM fan (Cheap $50 one)==> Y Splitter==> Ports 1 and 2. This assembly is on the outside of the box, sitting on top of it.

    1. Normally closed damper==> ducting stretch (if using collapsible ducting use extra, it shrinks under negative pressure)==> 420 CFM CFG fan==> Filter out to room (air being pushed through, straight from fan, no ducting between). As far as which port on the Y to use, use the most inline of the ports, with least air resistance.

    2. Normally open damper==> Ducting stretch to bottom of tent to air intake port.

    Now the wiring is slightly complicated, and to add the the confusion, on 2nd intake port of the tent, there is a normally closed damper. This damper is a bare intake from the room.

    The start of the chain is a heavy duty timer (which is used to set exhaust cycles), followed by a Split to 3 components.

    1. The CFG fan.
    2. The transformer for the dampers==> the dampers(make sure to use a junction box if you do your own wiring)
    3. (Optional) The sensing cord of a normally on switch.

    The normally on switch gets it's power from your CO2 controller and has your tank's solenoid plugged into it's outlet.

    The nice thing with this setup is that you can link more tents to the CFG fan as long as the have they're own inline fan and damper Y assembly. Since the power requirements of dampers are very low, you can use a fan with a high CFM on the end without much trouble. I will mention that this won't work with HPS or MH light setup, this is best suited for LED lit tents, as I said at the start of this novel.

    Keep Growing Crazy:smoking::wave:
     
  15. yo i am growing one plant for my first grow, buying a full out CF with a duct and fan seems like it would be overkill for one plant ? can i get something for under $50 that would do the job ?
     
  16. #36 earthbender, Jan 31, 2011
    Last edited by a moderator: Jan 31, 2011
    It's not a matter of preference. Carbon air "scrubbers" remove scent from the air.
    To work correctly, the "dirty" air is sucked in from the tent/grow area, through the carbon filter and out into the world. The fan is attached at the end near the window pointed outside, pulling air from the tent and releasing it.

    This accomplishes 2 things:
    1. the air coming out of the tent is not obnoxious (you don't smell up the block)
    2. the heat from your lights is released to prevent overheating (depending on your lights)

    carbon filter>> ducting>> (light hood> ducting> ) fan>> world
    (the air moves in, is cleaned, cools off the bulbs, is released- from LEFT to RIGHT)

    If you want clean air IN the tent, you control the air circulating in the house with a HEPA filter or a dehumidifier.
     
  17. #37 Dirtbud, Apr 1, 2012
    Last edited: Apr 1, 2012
    I realize this thread is old but seen someone pushing through a filter the other day and made me think of this.

    The fact that the "pre-filter" adds to the longevity of your carbon filter by filtering out dust particles that can clog a carbon filter; would suggest that you either need to suck air through it or create a prefilter for the inside part. Otherwise just do away with the prefilter on the outside if you are blowing through it. It's pointless.

    I could see how the filter can work both ways but is probably more efficient in suck mode. Which kinda blows cuz if you are in a small environment a carbon filter takes up too much room.
     
  18. If your pushing air into the carbon filter and the filter is outside the grow room is the air thats being released from the filter in any way harmful? smells kinda funny
     
  19. Hey all. I have a set up that doesn't allow me to have a filter in the grow room. I have to have it on the end of my ducting. I have my fan (250mm air force 2 and a 315mm x 1000mm PHAT filter comnected via reducer up in the loft. It works brilliant. Someone said about the pressure and I agree when sucking through the filter I noticed it was sucking more intence near the flange than at the rear of the filter but putting it with the air being pumped in I can feel an even pressure all over the filter meaning it will last longer as it isnt being used 90% at the front and 10% everywhere else. Iv used my current filter for 2 years with no problems. Im about to buy new though as its time (I replace every 2 years). I definitely agree with getting a bigger filter than fan. My fan can pump 2400 m3h and my filter can do 3200 m3h so I can run the fan full pelt during summer and have no issues.

    :)
     
  20. filter=fan=====light====outside. Is the only right answer.


    There are potential leaks at every connection. Also consider your light is not perfectly sealed.


    In The above diagram all air throughout the ducting is positive pressure. Any leaks will only leak clean fresh filtered air.


    Filter===light===fan===outside.


    As a example has failure waiting to happen written all over it. The whole system pre fan is negative pressure. If your ducting develops holes, the tape gives way a little from heat or stress, or the light fixture leaks the negative pressure will draw in stinky air.




    The only truly safe answer that I can come up with is like the first diagram. Positive pressure throughout with clean filtered air


    Try running the filter any way you want. When you wake up at 3am 5 weeks into flower and your whole house smells opressivly skunk you will know why.




     

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