To Suck or Blow? According to manufacturer doesn't matter?

Discussion in 'Grow Room Design/Setup' started by Prodigus, Jun 26, 2011.

  1. Trying to design my closet (still) and I was trying to figure out which would work best as far as stealth goes. For me, if I could have the filter be outside of the closet then that would allow me to maximize that space and keep the space as stealth as possible. I've read a LOT of posts arguing this little tidbit so I looked up my filter (Phat filter 12" x 6" ) to see if it had a preference. Nothing on the website where I bought it ( http://www.gianthydro.com/product_p/igspf126.htm ) but this statement:

    Given CFM rating is for scrubbing. Divide by 2 to get exhaust filter CFM

    I admittedly didn't understand the difference between scrubbing and exhausting so I sent an email to Phatfilter to ask. Just wanted to share their response in case it helps anyone. According to them, it doesn't matter. This was their response:


    "As with CAN filter, we decided to give minimum and maximum flow recommendations for clients because so many people were asking how slow and how fast their fan should be for a given filter. Generally, we scrubbing, meaning moving air in a circular pattern from a room through a filter and back into the room, the fan can be much faster because the air passes through the filter many times. When filtering, moving the air through a filter one time, the air should be a little slower to allow a longer overall contact time for the air with the charcoal. These are simply recommended flow rates. These recommendations have nothing to do with pushing or pulling through a filter, either is ok."


    So, according to their explanantion I can only run my fan at a max of 150cfm an hour (I think, lol). Closet will be 3'x4'x6' so that would be 72 cubic feet. Is 150 cfm going to give me enough air exchanges for a 400w HID?
    Neck/Tall

    Maximum Scrubbing
    CFM
    Maximum Scrubbing
    m3/hr
    Recommended Single Pass Filtering CFM
    Recommended Single Pass Filtering M3/hr
    6x12
    275cfm
    470m3/hr
    150cfm
    235m3/hr
     
  2. oops, I see the table didn't come out too well. Sorry about that.

    Neck/Tall \t\t\t 6x12
    Max Scrubbing CFM\t\t275cfm
    Max Scrubbing m3/hr\t\t470m3/hr
    Rec. Single Pass Filtering CFM\t150cfm
    Rec. Single Pass Filtering M3/hr\t235m3/hr
     
  3. Better to suck (pull air) so it pulls through any cracks, if you push, you push some of the air you are trying to exhaust out through any air leaks. I find pulling to be more efficient and easier also.
     
  4. Thanks Bohbo! That would be my first choice if possible... Do you think 150cfm exhaust will be enough for a 3x4x6 closet?
     

  5. I think it should do fine.
     
  6. If odor is a concern its better to push. That way your carbon filter filters all air in the tent and none escapes into the hood bypassing the filter.
     

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