Blower Noise

[Otis B Driftwood]

Hi Kids,

Hope all is well and warm.

Here, things are buzzin'. A little TOO LOUD.

Travis Avalon Rainier w/Blower here, just successfully relubed
bearings but STiLL makes one Hell of a racket. It's the mesh cage
partly welded to the fan body. The remedy for the past few years
is to shim the body on the hearth floor and where the cage meets
the shelf of the stove. It's worked OK but I can do much better.
When the cage is lightly pressed, the vibration ceases. This is
not an internal bearing noise.

Has anyone successfully silenced the fan rattle? How?

Thanks, All.

 

[Geoff C]

On my Clydesdale the fan housing vibrates against the mounting point on the body. I just wedged a roofing nail in there and it stopped it.


Sent from my iPhone using Tapatalk

 

[Otis B Driftwood]

Thanks Geoff, I found my extra wood shims from ax handles useful.
I'm good for at least one head replacement a year. I really need to
improve my swing ... one o' these days I'm gonna self-decapitate.

Thanks.

 

[gnappi]

If the fan blades are metal, vibration can be limited by either balancing the fan blades, or making sure the blades are all aligned. Both easily done.

A neighbor worked at a power plant balancing turbines and showed me that using a stable point like a pencil held near a hand rotated blade will show correctable (by bending / forming) deviations in the blade path.

To balance the blades remove them and install it in a pointed object held in a vise. Then rotate the blades and add weight to the blade that to not meet a stable point held near the blades.

Also, blade vibration gets worse the further it is from the motor. If possible and the blades are secured to a shaft with a set screw, moving the blades closer to the motor housing will make the motor shaft wobble less. Finally is space allows, mounting the fan motor on rubber grommets will absorb some of the noise / vibration.

Failing these attempts, replacing the blades is an option.

I've used these techniques on all sorts of fan blades from ceiling fans to A/C cooling fans, unfortunately none are usable on plastic blades.

 

[Otis B Driftwood]

Gnappi, GREAT points, thanks, I'll archive this for future use
because there WILL come a time. I'd just finished my first
major lube. Not easy, had to drill out the rivets but from there
it wasn't bad for this Useful Idiot. The armature slipped right
out, lubed and cured that bearing noise.

However, this is an issue created by the mesh that envelopes
the motors. Plastic fans, BtW. It seems there's a possible fix
in better fastening the mesh to whatever frame is there. I'd
thought of silicone or soldering it but not sure if that would
work and I'd hate to make a presumptuous mistake that
would make more of a mess. Believe me, I'm legion at that.

When I had the blower benched and successfully lubed it,
it purred like a kitten. No rattle. So it CAN run quietly.

As Geoff and I have done, we merely shimmed using various
objects but I've found that muffles 75% of the racket. Wood
makes sense. Combustible of course but not likely. I've thought
of taking some leftover Rokul®, good stuff BtW, and stuffing
it between the blower, hearth and stove shelf because it's
fireproof, but I'd think thin sheets wouldn't hold up.

One other possibility is to use fireplace cement to join loose
ends in the frame of the blower, but I'd think in time that
would dry and crack. That's why I thought of silicone but
I'd think that would stink up the room.

Thanks Again!

Any more ideas?

 

[Otis B Driftwood]

Seems this is a problem as doing a SEARCH on threads as these
I got a few more ideas and tried one just a few minutes ago.

So, as others note, my stove sits flush on the hearth but to slip
the blower on requires a gap of 3/16" to 1/4" lift distance on
the stove so the bottom can accept the two horizontal "clips"
on the blower. I shimmed using a wooden shim of approx 1/4"
height and slid it under the bottom of the stove, using a very
heavy screwdriver to lift the stove. The shim is positioned
dead center in alignment with the damper rod. I know that
using two shims would provide better balance, but already
the noise has significantly lessened. I also have found as
others have remarked that sometimes weight on the floor
just in front of the stove ( in my case, dead weight ) can help
the noise. That's impractical of course, but it seems the #1
cause for a rattling squirrel cage is not properly seating the
blower under the floor of the stove in the first place.

If it continues to stay quiet, Case Closed. If it doesn't, I'll
put a second shim under there, which is best anyway.

But yeah, buyers of blowers have to accept SOME noise
in any case, it's the nature of the beast.

Thanks for reading and replying.

Merry Christmas, Festivus, et al.

 

[Otis B Driftwood]

Update:

Peace'n'Quiet for nearly 24 hours. So, this is but one solution:

Check how your blower was installed. Therein could be the problem.

Note: The Squirrel Cage did rattle a little on one side, I shimmed that.

So far, so good.