What amount of CFM is needed to keep a 400W Cool Tube, cool to the touch?

Discussion in 'Grow Room Design/Setup' started by Mycelium, Dec 15, 2009.

  1. #1 Mycelium, Dec 15, 2009
    Last edited by a moderator: Dec 16, 2009
    As the title says, what CFM should be aimed for in a 400w cool tube system to keep it remaining cool to the touch? I have 2x high performance 120mm fans which can push 130 CFM when using one for intake and other as exhaust. Curious if that might do it, what do you all think?
     
  2. #2 jollyrancher1, Dec 16, 2009
    Don't force air down the tube.

    Draw air from it.

    I use a 6" Vortex on a speed control to keep my 400w cool.

    Those 70cfms are a little small.
     
  3. #3 Mycelium, Dec 16, 2009
    Thanks for the response Jolly, It turns out the fans I have are actually 130 CFM. The only load put on them would be by the bends in the ducts. The carbon filter and main cabinet exhaust would function separately and the cool tube would have its own intake and exhaust cycling air from outside the cabinet. I thought using both one at the intake and exhaust would be fine since there will be almost no load on them and perhaps it would stop the duct bends from reducing airflow. They are identical fans, so it would be balanced.
     
  4. #4 jollyrancher1, Dec 16, 2009
    I think you are in error.

    The load on the intake fan will be drawing the air in and the load on the exhaust fan will be forcing the air out.

    Shared load, but I don't recommend forcing air in.

    Just a suggestion, but what I do is put the ballast over the intake so that air gets drawn over the ballast as well as it is drawn over the lamp.

    That keeps the ballast from heating the room.

    Anyway, I have reservations about the amount of air flow those fans are rated for in your application.
     
  5. #5 Mycelium, Dec 16, 2009
    I knew those fans most likely wouldn't cut it, I was just asking out of curiosity. 400W really is overkill for my cabinet and what I need to yield. I'm going to run a 150W HPS with CFLs for side lighting instead. That will be perfect for my cabinet and require less airflow / noise. Wondering if 130 cfm would be enough for a 150W cool tube, based on what I've read I assume it will be.
     
  6. #6 baldie, Jun 16, 2016
    I am using a push/pull on my 6' cooltube due to exhaust duct run length of 25 feet with some bends. I appreciate your point about equal fans producing balance. Good point. I have read so much bad onfo by airheads it is comcal. Thanks.
     

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