CFM strenth ?

Discussion in 'Grow Room Design/Setup' started by HydroNator, Jan 6, 2013.

  1. Need some advice on filter outtake and fan intake. My room is 4 foot wide, 6 foot long, and 8 feet tall. Any advice on what kind of CFM I am going to need to successfully clear the air out and bring air in?

  2. Depends on how often you want to "replace" the air.

    4 x 6 x 8 = 192 cu ft.

    I use a 20 minute cycle as reference (soak then empty).

    Round it up to 200 cu ft and I get a flow rate of about 600 cu ft over an hour or 10 cfm.

    You don't need a big ass fan for the grow.
  3. Ya I am planning to run 20-30 min intervals of air replacement. Researching carbon filters and intake fans. If I only need 10 CFM it won't be as costly as I was originally quoting. Thanks for the input.
  4. IMO just stick a speed control on the fan and dial it in.

    You just need a good enough flow to get rid of the stink.

    If you are using Co2 then you may want to do a soak then empty.

    The problem with soak and empty is that a leak in the grow area will allow stink to bleed out during soak.

    I just have negative pressure on my chamber at all times and inject Co2.

    I may modify my chamber into a "breather" (as they are called) later on.
  5. I will not be using co2 or anything at first. I am hoping just emptying and refilling the air every 20 minutes will make a good environment for my plants to thrive.

  6. Not bursting your guys bubbles but unless ur running co2 20-30 mins is a bit much.. Ideally u wanna switch the air out every 5 mins, since your room is small however, u won't need a high cfm fan for this. A low cfm rating fan around 150 for a 4" duct would be fine. This will replace the are in your room about once every 2 mins afterthe carbon scrubber is attached (150cfm x 5min =750cf/5min before the filter as filters add slight drag resistance) they only run around 100watts as well. :)

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