is 80 cfms sufficient airflow?

Discussion in 'Grow Room Design/Setup' started by IRIESH, May 3, 2011.

  1. i am using 2 600watts in a 4X4 grow tent to grow 12 plants and fear the heat being too much, is an 80 cfm 4" inline duct fan sufficient air flow? im new to this and would appreciate an expert opinion!
  2. Is that a small propeller fan in 4" round duct? 120v from home depot/wal mart?

    It doesn't really move a full 80 CFM, its rated to be a "duct booster", designed to be placed in an ac/heating system that already has a blower, and just boost the air through a single duct. I cant speak with any actual CFM figures I don't own a velometer. Keep in mind duct length/construction (# of elbows) greatly reduce total CFM.

    I cannot speak for sizing a 600w light in a small grow tent since I have no experience with that setup. Mine is larger and has a fair amount of passive intake, and less lighting, and one 4" inline room exhaust works well in a 65 degree basement with a 400w light. I also allow a fair amount of passive intake air - very important for keeping temps down.

    In a smell proof situation if thats what you are after with your tent you will need a strong exhaust and plenty of intake to keep it in a negative pressure (always pulling air in, no smell leak) and keep temps down.

  3. No its not. I have a 400w HPS tube with a 6inch inline fan. You can go on amazon get it for 24 bucks. With just that air in my grow tent is about 78-80. I added another 6 inch to suck out ambient air surrounding the tube.

    I would suggest a duct going into your tube, duct going out and a fan pulling air then another set up to suck out ambient.
  4. You want air to be 100% exchanged in 5 min or less.
    Height x width x depth = x / 5 = your cfm at very least.

    so... 4 x 4 x 7 = 112 CFM. 112 / 5 = 22.4 cfms.
    Get an inline fan and you'll be good. Duct boosters just help move air through a duct...but it has to be already moved by some sort of inline fan...
  5. Thanks a lot guys! i have now switched my plans to 1000w in the grow tent and also picked up a powerful 6" inline fan for the air cooled reflector. im gonna vent that out of the room and put a portable window ac in the room the tent is in and open the bottom for negative pressure and to keep the cool air circulating! i appreciate all the advice cheers!

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