Inline Fan WAAAAY too loud

OneHit

Well-Known Member
I just got a 6' inline fan thats incredibly loud for the room that I want to put it in. Its not vibration noise, just the sound of it of the motor. Its a hydrofarm fan. Anything I can do to quiet it down?
 

OneHit

Well-Known Member
So, a wooden box with 2 6 in holes coming out of it, stuffed with insulation?

I was thinking about those S&P fans, how much more quiet are they?
 

Landragon

Well-Known Member
If the fan is more than you need, many can be speed-controlled which can lower noise significantly. Or what they said :)
 

Landragon

Well-Known Member
I lime the S & P mixvent but they aren't as quiet as some may claim. For reference, I have 4" versions of vortex, can-fan, mixvent and s&p powerline series. Out of these four the can is quietest and the powerline the loudest to the ear. The can is also the largest by far and not suitable for many situations that would require only 4" fans. The speedster is a great speed control for the $. 17-30 bucks depending on source. It is non-linear though and when it seems you have turned it down 10% you have really lowered 30-50% depending on load and factory calibration of the units rheostat. Best way to figure value is with a kill-a-watt and note wattage change. Big however though, the powerline and some other fans including the mixvent I have (td100x) are louder when speed controlled. There is a resonant hum from the pulse wave modulation used to control speed. Essentially you can picture a bicycle crank being turned and it's effect. At full blast the rider pumps continuously thus smoothly turning the drive wheel. The rider feels little deccelerative effects as they are constantly moving forward. But if the rider moves with repetitions of pumping .25 seconds and coasting .25 seconds, they will essentially oscillate in feeling a forward-backward movement. This is what the fan blade does since it is balanced to spin at full speed. The sound becomes apparent at real 60% or lower which is more like a 10 -15% reduction on the speedster or similar devices. This is not a malfunction of either the fan or the speed controller, but just incompatiblity between the devices. It is safe to lower untill the hum becomes apparent. Can-fan and vortex are fully speed controllable without hum. There is a blue plastic sunleaves fan that I have had the chance to play with the 6" version. If the 4" is similar, will be a good contender. The model slips my stoned mind now but it is the blue plastic one so not too hard to miss. Don't let plastic scare you as it is extremely efficient at vibration damping. Much more so than steel. Can-fan and vortex each use vibration damping paint which is noticably better than the powerlines. Sorry for the breadth and scope but my girlfriend got busy with Christmas wrapping and I'm bored as all get out. :::::edit::::: I am high. You are going 6". Never tested can, vortex is like a rocket engine, sunleaves is nice, my out of state buddy saw my stuff and told me to gets mixvent. I havnt visited him or seen the 6" version.
 

OneHit

Well-Known Member
Nice response, real informative. i guess ill give the speedster a try, but kinda sucks I have to spend another $30 for it, when its already a $140 fan. I think the vortex is similar to the hydrofarm one, so hopefully it doesnt become louder with it attached.

Is your speed controlled vortex louder than the full power mixvent?
 

funkdocKT

Well-Known Member
always buy the next fan size up from what you need...that will make you able to keep the temp you want without blasting it full speed (get a fan control unit) and therefore give you the sound you dont want...

the Sunleaves Wind Tunnel 409CFM 6" is really really really quiet and works awesome

my $0.02
 

Piemeal

Active Member
Stumbled onto this post by mistake but It rings very familiar to me. My 4' vortex is very windy sounding when not speed controlled but no motor sound. I bought the speed control they sell at he shop with the Vortex. Not wired in just a dial with an A/C In/Out (dial-a-temp). Below 70 or 80% the hum is unbearable. Plus , even on the low setting it doesn't seem to turn the speed down much. Maybe 25% speed reduction with the loud hum. I prefer the sound of the air to the hum so I moved the speed control to a little computer fan which works great. I'd love to hear if somebody has a solution to this!
 

OneHit

Well-Known Member
hmm, i thought the vortex was one of the fans with no hum? I have read in the S&P fan thread that a speedster creates the humming there also. Is there a way to know if this fan will have a hum before i purchase the speedster?
 

Landragon

Well-Known Member
From what I understand through phone calls to manufacturers, moe four and some six inch fans use motors not designed to be speed controlled externaly. On my speedster it warns to not use with capacitor driven fans. On each fan with noticable hum, there is a black plastic "can" inside the junction box. The S&P each have it, and also have two speed hard wiring for low and high. The windtunnel is the sunleave blue plastic one I mentioned and was good. Though I didn't have the speedster then. My 6" vortex is not producing a hum when slowed. For whooshing wind noise, almost nothing beats insulated duct, and if needed a duct muffler.
 

Landragon

Well-Known Member
And the hum is producednby the fan. The conditions to allow the hum are create by the speedster.
 

uhavealighter?

Active Member
always buy the next fan size up from what you need...that will make you able to keep the temp you want without blasting it full speed (get a fan control unit) and therefore give you the sound you dont want...

the Sunleaves Wind Tunnel 409CFM 6" is really really really quiet and works awesome

my $0.02
The suncourt centrax fans are the same as the sunleaves windtunnel fans. They just change the name on the box and add a pretty sticker. Centrax fans are cheaper.
 
Top