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Inline fan noise problem!! Help

Discussion in 'Indoor Marijuana Growing' started by AliensWorkshop, Dec 18, 2008.

  1. I just got my complete setup last week. Everything's put together and ready to go. Thats when i realized my 6" inline fan was noisy as hell! Its in a 4.5x4.5x6.5 grow tent on a 600w system. The setup is in my room and my 2 other roommates can hear the fan upstairs. I have a carbon scrubber on it and ducting is fixed to the lamp shade and still there is alot of noise! I'm thinking maybe a fan controller can bring the speed down quite abit and hopefully take most of the sound out.

    Has anyone run into this particular noise problem?? And is a fan speed controller a good option?
  2. I had a similar issue. I found that by blocking out the top 1/4 portion of the intake with duct tape you change the airflow and stop howling noise they tend to make. In this case the noisy fan was right next to the intake. If your fan is located somewhere else then this might not work.

  3. Is it the fan itself that is making the noise or the air thru the ducts? If it's the airflow, you can make a muffler. If it's the fan, a fan controller would help. You could try wrapping the fan in foam and duct tape for a temp fix.
  4. also try to use lots of silicone around the fan and all the fixtures associated with it. could help damp the vibrations. all the other guys ideas should work too. im just using a small computer fan and it was quite noisy until i got it nice and snug and siliconed in place
  5. #5 AliensWorkshop, Dec 18, 2008
    Last edited by a moderator: Dec 18, 2008
    thanks for your input guys. And no its not the vibrations, i have them on bungees which is working out nicely. Its just the actual fan itself from the suction. It sounds like a small jet taking off in my room. Cutting off some circulation with duck tape is a good idea. I even tryed putting a 6"-4" conversion bracket on the intake to try and muffle some out. It did a little bit but can still be heard over the whole house.

    I am really considering building a little box for the fan to sit in and line it with egg shell insulation and hopefully this will really cut down a major part of the noise. If it dosn't work i may just have to return the fan and get a small ducting inline fan.
  6. I have a 6" valueline inline fan that yes, sounds like a mini-jet, as you described.

    Question, do you have it pushing through the filter or pulling? If you have it pull through the filter it will cut down on the sound a bit as compared to pushing the air through it.

    The majority of the sound comes from it sucking in so much air, so putting a load before the suction helps out.
  7. get the fan controller. the majority of the noise is from the moving air, not the fan itself.


  8. Right now I dont have the filter connected cause nothing is growing im just trying to perfect the setup before the seeds get here in like a week. But I did try the filter as a the intake instead of exhaust, and you were right it does bring the sound down. But another issue i ran into was massive ammounts of heat. Doing trial runs with my 600w lamps i realize that just using the fan to pull air from the light and circulating it with the carbon scrubber within the tent does nothing to bring my heat down. I may just have to leave the 6" inline soly to cool the lamp down and exhaust straight out the tent. But then get a smaller 6" ducting fan, flange it straight to the tent for exhaust and putting the scrubber on the other end to purify the out bound air.

    Does anyone thinking running 2 6" inline fans (1 being smaller cfm rating) is going to be too over the top for a grow tent and spike up my noise pollution and electrictricy usage considerably?

  9. lindedrivr your right the actual suction of the air is making all the sound. When i put my hand infront of the suction side and stop most air intake I can hear the fan motor is very quiet. Its just hearing 450 cfm getting pulled through it is what really makes the nosie. Which sucks for me cause im realized that the extra muffle i would get from my carbon filter wont be happening since my fan is directly to my lamp shade and i need it to cool everything down and putting a filter on it is just going to slow it down. I dont even think building a little insualation box for the inline fan will help since the suction will be coming from inside the light not where the light intake is at :(
  10. are you using a air coolded reflector? if not that can help with reducing heat alot, and you can get split fixtures to exhaust your box/tent.

  11. ding ding ding, put the filter on. geez. If it's still too loud go down to a 4".
  12. Would a 4" not make the same or more noise as a 6"? I'd imagine the larger the diameter, the lower the noise due to lower air velocities needed to acheive the cfm rating needed.
  13. Put a variable speed controller and a muffler on it. The controller is great but when you turn it down, you not only get less noise, you have less air flow,....so what's the point. Add the muffler and use it as needed.

    The heat is another issue, I'd have a 6" on the light, venting directly out of the tent with a length of duct that is as short as possible. Wrap that length of duct with insulation and it will keep the noise lower and keep the heated duct from allowing heat to diffuse back into the room.

    I'd use a separate 4" or 6" fan for the scrubber.

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