HELP!!! Smell problem! Need advice soon!

Discussion in 'Grow Room Design/Setup' started by kmcconkey, Sep 14, 2009.

  1. Does anyone have any good links to ventilation guides or anything? I have a 36 cubic feet grow tent that i am having issues with keeping it smell proof. I have only one plant (LST) with around 14 colas.

    I have constructed a scrubber exhaust system but the smell is still escaping.
    I am in the process of duct taping around all the vent ports and such to try and get it to become as air tight as possible.

    My setup pulls air through the carbon filter (which is inside the tent) and then out through an exhaust port. My ports and vent tubing are 4" but the fan is a 6" 250cfm inline duct booster fan i bought for around 25$.

    My questions include,

    Is this fan sufficient for this space? or do i need to upgrade to the 120$ can fans?

    Does it matter if the air is being sucked through the filter on the inside of the tent or does it work better to push the air through the filter on the outside of the tent?

    Attached Files:

  2. I bought some cheep really smell candels the cinnamon kind grind em up and place where your vent exsaut hose is. Makes your house or outside smell good.
  3. Im no expert but i think you want the fan to be pushing the air out thru the filter instead of sucking it through. I'm about to set my tent up as well and im gonna use a fan similar to yours but i,m gonna use two of them in series, pretty much the same setup you have but with the duct work, fan, and filter on the outside of the tent.
  4. I think it may be that you have too much fan, not too little. I just got schooled on this at thye grow shop over the weekend. In short, people think the more times they can replace the air in the room, the better, but that's not the case. If you pull it over the carbon too fast, it doesn't get time to make contact and get filtered. If you look at most commercial scrubbers, they have very low cfm recommendations. The low end of their recommendation is for smaller spaces and smaller cans like yours and mine.
  5. wow thanks for the responses! I think i'll save the candle idea as a last resort ;)

    That makes since about too much air flow. however i have heard people make claims that these cheaper duct booster fans dont have the strength to push air through a filter which i believe to be false because i can feel the air being sucked through the carbon filter.

    Unfortunately i dont think there is any way to slow this type of fan down that i know of. I know they make fan speed controls but i dont know if they work for duct booster type fans...

    I'll try making my carbon filter a little thicker or maybe larger and i will also try configuring the fan to push the air out through the filter rather then suck through it. I have to wait till tomorrow to get back in the tent while the lights are on.

    Does anyone think this will work as a solution?
    Anyone have a similar experience with solving this type of problem?
  6. Well i have found more evidence that shows that pulling air through a filter is more efficient. but if my fan's CFM rating is too much for that space it might not hurt to try pushing the air out through the filter in stead. I added another layer of the carbon filter cloth last night so hopefully that will work out good. if not i will try reversing the setup and if that does not work then i might be looking at buying a pre-made setup.

    Oh and i also duct taped all the possible air leaks around the unused vent ports and such. hopefully this will help create negative pressure.
  7. There is a way to slow them down. HERE is your answer.

    Good to have anyway so u can slow it down at night or when you dont need as much circulation,etc Cheap and easy to set up. Fan plugs into control, control plugs into wall.
  8. Yeah you want to be pulling air through the filter. Those duct booster fans are meant to be used as an aid to your squirrel or inline fan when you have to run longer spans of ducting.
  9. But that fan is sucking air through the filter, not pushing. Right? It gets exhausted outside the grow area, not back into it, right?

    also, add/replace carbon, use more this time. (Unless it's new carbon, then, just add some more)
  10. When the filter is inside your enclosure, I consider the air being "pulled" through the filter. When you have your filter on the outside, I consider the air being "pushed" from inside the enclosure out through the filter. I have been seeing that lately, people buying those booster fans cause whoever they ordered them from put these high-ass cfm rating claims on them. That number might be the the max cfm it will boost, meaning it will help move aloung that amount of air, but cannot help move more.
  11. you should put the filter outside of your room at the end of the exhaust fan so that way it blows the smell through the fan then the filter then out (Fan-Filter-Outside) instead of (Filter-Fan-Outside)

    basically take your fan piping and move it all outside of the room.

    Attached Files:

  12. I am new, but I think you want a ozone maker, or some ducting with an inline fan and a carbon filter at the end.
  13. wow thank you for all the responses! Again though there is a lot of people who think pulling is better and some that think pushing is better. the extra layer of carbon filter cloth seemed to work great but a day later the smell is again back (although not as strong). I dont think this fan could handle a 3rd layer of carbon cloth. I also feel that a tent is never going to be smell proof (escpecially the shotty one i bought from HTG supply) so we'll see.

    thank you for the help everyone!!! Once i get the smell under control i will post my solution for other tent-growers to look at.

    If anyone has/is growing in a smaller grow tent i would LOVE to see some pictures of how the smell problem was solved!
  14. Why do you think that is more efficient? If that was the better option you would see more people with filters outside their grow spaces. That is also going to dirty the INSIDE of your filter. Why do you think can style filter's are sold with a pre-filter cloth on the OUTSIDE? The air was meant to be pulled in and throught the filter and fan.
  15. its just my $.02

    like the name of the attachment
  16. well to be honest i flipped the system so it blows out through the filter and i gotta say it seems to be working....oh wait i toked like 10 minutes before i did that....which was 11 minutes ago...:rolleyes::smoking:
  17. yea its not working....:(...i can feel air being pushed through the filter and it seems to smell ok:confused:. I'm guessing the problem is that the fan is not powerful enough to keep negative pressure in the tent?

    What are some basic rules to achieve negative pressure?
  18. You don't want negative pressure. You don't want to be sucking out more air than you are taking in. I have read positve pressure helps keeps pests in check. It is hard for them to fly through the positive pressure, vs. negative pressure that just sucks everything in. You obviously want to be exchanging air, but you want your plants to benefit from that.
  19. if your exhaust is at the top, move your intake to the bottom so that way the air has to travel around the plant then exit.
  20. #20 kmcconkey, Sep 17, 2009
    Last edited by a moderator: Sep 17, 2009
    Really? I have always heard that negative pressure is the best. I'm not worried about pests as much as i am worried about the smell.

    My intake is on the bottom of the back side of the tent and my exhaust is at the top of the back of the tent. i just ordered this, Discount Hydroponics - C.A.P. ValuLine Blowers

    and plan to build a DIY carbon filter using chicken screen and vent parts and such. Can anyone recommend a top-notch activated carbon filter i should use for the scrubber?

    I will most likely go back to sucking the air through the filter (inside the tent) and pushing the clean air out.

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