Any ideas on how to muffle a bathroom type vent fan? I tried it out
at the store and it wasn't too bad, but after getting it installed at
home, this thing is almost deafening. The drone of this is incredibly
obnoxious.

What I suspect is the problem is that in the store the fan was setup
to push into a "dead" duct, so there was little air movement and thus
little noise. Now in my installation at home, there is a lot of air
moving and also a lot of noise.

For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes. Can I place some sort of smooth venturi type restriction in
the exhaust side of the fan to quiet this down a little. I don't need
this much airflow.

I installed it to draft warm air up the staircase and to stuff it into
the attic. Before I used to alway open the attic access door and let
the attic vent fan draw air as it needed. This worked fine, but the
attic access was in the closet in our master bedroom, neccessitating
leaving doors open and the hazard of loose insulation ending up on the
clothes in the closet.

It accomplishes the desired effect of cooling the house(quite well
actually), but the noise isn't tolerable. I have it wired in parallel
with the thermostat switch for the attic fan, so it only runs when the
attic starts to get to warm but it needs to get muffled somehow.

Ideas?

JW

Check the mounting. Are the screws evenly and gently tightened? You
might try loosening them a skoach when the fan's running, if you can.
Then slowly ease them back in. I had a real noisy muffin fan in a
Miller welder that got quiet when I tightened the screws.

Grant

Jeridiah wrote:

Any ideas on how to muffle a bathroom type vent fan? I tried it out
at the store and it wasn't too bad, but after getting it installed at
home, this thing is almost deafening. The drone of this is incredibly
obnoxious.

What I suspect is the problem is that in the store the fan was setup
to push into a "dead" duct, so there was little air movement and thus
little noise. Now in my installation at home, there is a lot of air
moving and also a lot of noise.

For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes. Can I place some sort of smooth venturi type restriction in
the exhaust side of the fan to quiet this down a little. I don't need
this much airflow.

I installed it to draft warm air up the staircase and to stuff it into
the attic. Before I used to alway open the attic access door and let
the attic vent fan draw air as it needed. This worked fine, but the
attic access was in the closet in our master bedroom, neccessitating
leaving doors open and the hazard of loose insulation ending up on the
clothes in the closet.

It accomplishes the desired effect of cooling the house(quite well
actually), but the noise isn't tolerable. I have it wired in parallel
with the thermostat switch for the attic fan, so it only runs when the
attic starts to get to warm but it needs to get muffled somehow.

Ideas?

JW

On 12 Jul 2004 10:46:20 -0700, (Jeridiah) wrote:

||Any ideas on how to muffle a bathroom type vent fan? I tried it out
||at the store and it wasn't too bad, but after getting it installed at
||home, this thing is almost deafening. The drone of this is incredibly
||obnoxious.
||
||For reference - fan is 8" with a baffle rated at 180CFM and 6.5
||sonnes. Can I place some sort of smooth venturi type restriction in
||the exhaust side of the fan to quiet this down a little. I don't need
||this much airflow.

Mask the impeller
Depending on what shape the fan and motor is, you may be able to fasten a thin
disk of plastic or aluminum (metal content) to the face of the housing or even
the blade to remove some of the blade surface. It might be more effective to
make a large "washer" to mask of the outer inch or so of the fan (front or back)
since that's there the highest speed is and probably the source of most of the
noise.
Texas Parts Guy

In article ,
(Jeridiah) wrote:

For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes.

Egad. First thing would have been to pay attention to the sones rating
before purchase, or return it and buy one with a _much_ lower rating.

If you want to choke it down, it need not be all that complicated - put
a damper in the duct.

--
Cats, Coffee, Chocolate...vices to live by

In article , Jeridiah says...

Any ideas on how to muffle a bathroom type vent fan? I tried it out
at the store and it wasn't too bad, but after getting it installed at
home, this thing is almost deafening. The drone of this is incredibly
obnoxious.

Some folks like that. Loud fans, that is.

Womenfolk mostly. That means they don't have
to run the water in the basin to mask the
sound of the water running into the toilet.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Sometimes just a small reduction in speed makes a lot of difference in the
noise level. A couple of ways to do that, a bucking filament transformer,
secondary 12 to 24 volts, a series light bulb, choose the wattage to get the
speed you want, or (outside chance) a lamp dimmer that may or may not work with
an inductive load.

Earle Rich
Mont Vernon, NH

On Mon, 12 Jul 2004 13:18:17 -0700, Grant Erwin
calmly ranted:

Check the mounting. Are the screws evenly and gently tightened? You
might try loosening them a skoach when the fan's running, if you can.
Then slowly ease them back in. I had a real noisy muffin fan in a
Miller welder that got quiet when I tightened the screws.

0.5 to 2.0 sones is considered quiet. He bought a 6.5 sone fan.
http://www.naturalhandyman.com/iip/i.../infexh.shtm#3 shows
listings only up to FIVE sones. g

Exchange it for a quieter style or learn to live with it, Jeridiah.

P.S: Shy people LOVE noisy bathroom fans.

P.P.S: Venting stairway air to the attic? Have you looked into
using a thermostatically controlled louvre in the ceiling instead
of a fan?


Jeridiah wrote:
For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes. Can I place some sort of smooth venturi type restriction in


-----
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http://www.diversify.com Comprehensive Website Development

The Bathroom Fan FAQ has some stuff on this
(http://pages.quicksilver.net.nz/geoffm/)
In short, use an inline fan, mounted as far as possible from the
inlet. mount it on wire or strapping. Use a GOOD quality fan, use a
big fan and speed control it down. use insulated ducting and a couple
of bends between the fan and the inlet and outlet. Look at using an
acoustic silencer.
It is easy enough to make a fan system so you can't hear it. It takes
space, time and some money - and attention to detail.
Geoff
--
"Peace through superior firepower"
"How to build a rolling road dyno", Radar detector FAQ and
Forte Agent automation FAQ both at http://www.bigfoot.com/~geoff_m
REMOVE "DELETEME" SPAMBLOCKER FROM ADDRESS TO REPLYTO USENET POSTINGS

Ecnerwal wrote in message ...
In article ,
(Jeridiah) wrote:

For reference - fan is 8" with a baffle rated at 180CFM and 6.5
sonnes.

Egad. First thing would have been to pay attention to the sones rating
before purchase, or return it and buy one with a _much_ lower rating.

If you want to choke it down, it need not be all that complicated - put
a damper in the duct.

This was the only one that met other specs of the problem. In any
case, I did notice the sound rating. I did try it out at the store in
their bench display. I shut off all of the other fans and tried this
one by itself. It was noticeable, but not "loud". Some of the others
were barely audible. Again, I think this is due to the fact that they
are allowing the motors to cavitate the air and have very little "air
noise".

The "other" fans with sonnes ratings of around 2 also had cfm's of
about 40 and cost 5x what this one did. What exactly is a sonne? I
am aware of dB for rating sound, but don't know what sort of unit a
sonne is.

I built an air tight super insulated house, and needed my bathroom fan
on all night for air exchange [I know, I never got around to building
the heat exchangers because we started having kids.].
I had the super quiet mode fan, but I wanted lower flow and even lower
noise.
I got a dimmer switch that was rated for motors.
That way I could dial in the noise and air flow I wanted.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

On Mon, 12 Jul 2004 21:09:55 -0700, Larry Jaques
vaguely proposed a theory
.......and in reply I say!:

remove ns from my header address to reply via email
Missed the OP. Possibly KF'd the poster?

Swap it for the lavatory fan. I have always felt that the lavatory fan
has far more value for noise than for extraction.

On 13 Jul 2004 06:00:28 -0700, (Jeridiah) calmly
ranted:

The "other" fans with sonnes ratings of around 2 also had cfm's of
about 40 and cost 5x what this one did. What exactly is a sonne? I
am aware of dB for rating sound, but don't know what sort of unit a
sonne is.

http://hyperphysics.phy-astr.gsu.edu.../dbcon.html#c1


---
Annoy a politician: Be trustworthy, faithful, and honest!
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http://www.diversify.com Comprehensive Website Development

P.P.S: Venting stairway air to the attic? Have you looked into
using a thermostatically controlled louvre in the ceiling instead
of a fan?

Where would I find such a thing? Hadn't been considered, but now
maybe.

For the record, the fan has been doing an awesome job of cooling the
house "naturally", the inside vs outside temp "feel" is easily 10
degrees. Haven't found a thermometer to check the difference, but it
is worth the effect, it is just a matter of making the noise less.

JW

why do bathroom fans always come on with the light switch, when they are
most useful after the light goes out?

"Jeridiah" wrote in message
om...
P.P.S: Venting stairway air to the attic? Have you looked into
using a thermostatically controlled louvre in the ceiling instead
of a fan?

Where would I find such a thing? Hadn't been considered, but now
maybe.

For the record, the fan has been doing an awesome job of cooling the
house "naturally", the inside vs outside temp "feel" is easily 10
degrees. Haven't found a thermometer to check the difference, but it
is worth the effect, it is just a matter of making the noise less.

JW

On 14 Jul 2004 14:23:21 -0700, (Jeridiah) calmly
ranted:

P.P.S: Venting stairway air to the attic? Have you looked into
using a thermostatically controlled louvre in the ceiling instead
of a fan?

Where would I find such a thing? Hadn't been considered, but now
maybe.

Think "greenhouse parts" and Google it.


For the record, the fan has been doing an awesome job of cooling the
house "naturally", the inside vs outside temp "feel" is easily 10
degrees. Haven't found a thermometer to check the difference, but it
is worth the effect, it is just a matter of making the noise less.

Add an ess of carpeted tube/box channels to the intake.
That should tone it down considerably for a very few dollars.

Next time go to several stores to find a cheaper, quieter
fan, eh?


---
Annoy a politician: Be trustworthy, faithful, and honest!
---
http://www.diversify.com Comprehensive Website Development