Fan Control

ilmbk

Member
Just received my Tjernlund 4" inline, with speed controller by the same company. It's extremely loud. Even with the controller at the lowest possible setting it still seems to be moving quite a bit of air. How slow can generic speed controllers get? Down to a crawl? I only need to move a small amount of air and this thing can't get slow enough
 

skunkd0c

Well-Known Member
4inch fans are normally very quiet 30+ db range
most fans do not work well with standard cheap controllers they hum
these things work just like a light dimmer switch
so some folk use variable transformers (variacs) instead to slow the fans down without the hum/buzzing noise but variacs do not tend to offer as much control over the speed, also running the fan at a lower speed than it was intended can in some cases shorten the fans life

if your issue is with noise, best thing to do is put your fan in an insulated box, rockwool inside the box works well to trap the sound
also sound insulated ducting will also reduce the noise , much of the sound, is the rushing sound of the air through the ducting
any fan over 40 db is pretty loud, fans rated at 30db can still move lots of air, and are no louder in a room than a small house fan heater

peace
 

ilmbk

Member
I haven't connected it to any ducting yet, so that may bring it down some. But it's certainly louder then anything else in the house just running wide open. It's also an issue that it's really moving too much air... I'm working with a very very small space (think, rubbermaid grow box). PC fan was more than enough to cool the area but smell will be an issue so I invested in the inline to push through a carbon filter. Now I'm sitting here with a fan and filter and looking at the possibility of not being able to use it. Disappointing for sure - money into this setup and 0 grams out ...
 

Mattemil

Active Member
And BTW not all speed controls make that hum....I use one of the cheap "speedsters" with my 4 inch fan and have no hum and yes it will run at a crawl.
 

ilmbk

Member
I put a voltmeter on the speed control and on it's lowest setting, it's still feeding 88 volts... could be why it seems to make little difference ... ?
 

ilmbk

Member
I decided to purchase a variac. Super quiet... brought it down to about 50v and it's a nice easy breeze. Just what I needed! thanks guys!
 
Top