Sounds like a leer jet is in my closet, advice for noise reduction

Discussion in 'Grow Room Design/Setup' started by sizzlasia, Aug 26, 2007.

  1. Since I got my 400 all hooked up and my 265 whisper fan, my closet is loud as anything. Im running the metal ducting etc and its so loud its unbearable.. the fan motor istself is quiet just the air moving through the ducts im assuming is making the noise. I searched and read something about egg crates.. any ideas would be great. I read mixed reviews about dimmers and thats not looking like an option
  2. It's just a wild assed idea, but what about insulating the ducts? A roll of that fiberglass and foil duct insulation might dampen the noise. Also, try isolating the source of the noise. I'm thinking that the point where the fan meets the duct would be a big noise maker, transferring vibrations and such to the duct where it kind of amplifies. I don't know how big of a duct you're using, but can you rig some sort of coupling between the fan and duct that wouldn't transfer sound?

    where is this venting?
  3. Its a 6 inch, so right now I have 6 inch alluminum ducting.. and yeah I hear you maybe I should go get one of those neoprene duct fittings.. the box is in my closet and the duct is running to the side wehre there is nothing
  4. Good call, I got the ducting and there is virtually no sound coming out of the duct, but the area where the fan is still transmits alot of noise out the box. Any ideas?
  5. you can use rubber washers to minimize bounce from the fan.

    other than that you need to insulate it, make sure everything fits well, and turn the t.v up when someone is in the rooms around the grow
  6. The fan is mounted on 1/4 inch door sealing stuff.. how do I insulate it for sound? The ducting is insulated and shut the noise up 100% on that end of things.. now theres still a decent bit of noise coming from the fan area
  7. I'm glad that insulating the ductwork muffled the noise. Did you isolate the fan from the duct? Is that where the fan is making the noise, or is it securely fastened to the box/wall etc. with screws? The weather stripping sounds like it should prevent the fan from vibrating against the box. Can't tell from this end, you'll just have to listen until you find where the noise is coming from.

  8. once i got my dimmer and suspended my fan by bungie cords (not screwd to anything solid) my shits been perfect. except at the exit point where it blows really strong, flatens all the grass for a foot or two infront of it!

    normaly i leave it cranked full on, its a lil noisy then,but quieter than normal "house sounds" so its not a big deal, but i can turn it down to damn near silent, still keep my room vented, just not as cool.(cool keeps the smell down a lot, i like 75-78 degrees) i'd be comfortable leaving it that way for a week or two if i had to.

    and if its quiet again, no ones over etc.. i'll just crank it back on full. I also lined the floor of the grow room with foil buble insulation, and the door is sealed with foil buble ins. with a ziper opening behind the door opening, haha makes it totaly light/smell proof and helps a ton with sound.
  9. Yup.. Its screwed into the roof of the box with weather stripping in between.. but there still noise coming from that area.. would like to silence it completely if i could

    Well the way I have things setup thats not really an option because I have a "whisper fan" (check out mounted to the roof of my box with glass about 3 inches below that.

    What is foil bubble insulation and where'd you get that?
  10. air restriction could be causing the noise. remove the duct from the hood completely and open the doors so the air is totally unrestricted and see if its still loud, if not re pipe the duct. but you may need some metal duct, the flexible kind will make noise due to the material. the ridges that make it flexible act as a turbulator and the length of the run will dictate sound tone. you want smooth duct like used for heating systems.
  11. If you use a dimmer switch on your fan, you are damaging your fan and its also dangerous. Dimmer switches are not meant for fans!

  12. Yeah regular dimmer switches you'd use for lights are not good for heavy duty exhaust fans like we use...

    What you'd need is a "solid state speed control" not for dimming lighting, or ceiling fans, but for pole style/heavy duty inline exhaust fans as we use.. Most on the market are speed controllable with the proper speed controller.. No humming, no nothing when you got the right dimmer/speed controller hooked up.. My fan goes from silent to leer jet with a twist of the dial.
  13. Good call on the air restriction. My fan makes more noise when I have some of the intakes closed off.

    He is using aluminum ducting; when he wrapped it in insulation that dropped a lot of the noise, but it sounds like the fan is humming and it is being resonated by the mounting.

  14. there is aluminum flexible and aluminum hard duct. the flexible aluminum duct has ridges on the inside - no good for systems w/ forced air.
  15. Bingo.. the heating style insulated ducting killed the noise from the end of the duct, its just where the fan is mounted itself seems to be making noise
  16. yes, restriction makes wind turbulence noise. the same effect applies to heater grilles. i had one in right next to my couch in a livingroom that howled like a banshee when i tried to close the vent which didn't seal all the way. to stop it, i taped a piece of cardboard over the vent and it totally stopped it from making any noise and the wide open unit in the corner stayed fairly quiet as it was wide open.

    the whole "dimmer" concept doesn't sound bad either. fans DO have a sort of dimmer too at that. most fans have high, medium & low settings on them which basically regulate the power to the motor. i don't know how light dimmers differ. i would think it's just a difference between potentiometers vs. resistors. pots are continuously variable & resistors have set values.

    just lower your airflow. if it's that loud, you must be moving alot of air.

    another thing you could do is add more ducting like another line or use larger diameter tubing. then, the air would meet less resistance and flow more easily. it's the same idea behind a whistle, the harder you blow, the louder it gets. the less resistance air gets, the quieter it gets like a gentle breeze.

    sounds like you're overtaxing the system trying to force too much air through it.
  17. Probably correct, but too much circulation is not a bad thing! The box isnt very big for the temps to stay exactly the same inside it as outside with a 400 watter within 2 inches from the canopy.

    Its alright though.. pretty sure im gonna lose the box soon anyway and upgrade
  18. This Might sound to good to be true but the easiest thing to do is extend the ducting outside of your grow, im using 6" flexi white ducting, and i wrap it in a bath towel, with straps to hold it in place, it dampens the sound and makes it light tight.
  19. too much circulation through too small a hole IS a problem especially if you're trying to be stealthy.

    if you just double your airl ducts, then each would work half as hard. you get the same or even BETTER circulation without stressing a single hose. it's an easy and cheap DIY solution especially if you want max air flow

Share This Page