I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? How much distance to
leave around the unit for good airflow? What CFM rate? What sized fans? I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.

"Robert Green" wrote in message
...
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to
the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's
sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull
and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping
in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use? How much distance to
leave around the unit for good airflow? What CFM rate? What sized fans?
I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.

Make sure your box will come apart, so you can empty the thing

On Aug 15, 2:24*am, "Robert Green" wrote:
I want to truly silence my Hayden central vac. *I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. *I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? *How much distance to
leave around the unit for good airflow? *What CFM rate? *What sized fans? *I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. *I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

Bobby G.

I would talk to Hayden , I bet they know what is most cost effective
and works. The Sound- frequency, frequencies, you are deadining have a
wave length that some materials absorbe better than others and foam
may not be as effective as something cheaper. An example of why you
only hear bass from cars or homes that are to loud is the wave of the
low frequency can be 3-4 feet long, and carpet stops the real high
frequencies as they can be only 1/4" long. The frequency of the
whine, Hayden or a musician could figure out, then an enclosure needs
to be designed for that area of frequencies. I guess a 1" drywall box
with 6" fiberglass batts open to the motor might be better and cheaper
but i cant hear the vac from here, the fan idea and completely closing
it is risky, you cant rely on the thermal cutoff in their unit for
saftey. Maybe rubber mounting bushings of the vac would do alot as its
probably vibrating the wall.

On Aug 15, 8:20*am, ransley wrote:
On Aug 15, 2:24*am, "Robert Green" wrote:





I want to truly silence my Hayden central vac. *I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. *I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? *How much distance to
leave around the unit for good airflow? *What CFM rate? *What sized fans? *I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. *I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

Bobby G.

I would talk to Hayden , I bet they know what is most cost effective
and works. The Sound- frequency, frequencies, you are deadining have a
wave length that some materials absorbe better than others and foam
may not be as effective as something cheaper. An example of why you
only hear bass from cars or homes that are to loud is the wave of the
low frequency can be 3-4 feet long, and carpet stops the real high
frequencies *as they can be only 1/4" long. The frequency of the
whine, Hayden or a musician could figure out, then an enclosure needs
to be designed for that area of frequencies. I guess a 1" drywall box
with 6" fiberglass batts open to the motor might be better and cheaper
but i cant hear the vac from here, the fan idea and completely closing
it is risky, you cant rely on the thermal cutoff in their unit for
saftey. Maybe rubber mounting bushings of the vac would do alot as its
probably vibrating the wall.- Hide quoted text -

- Show quoted text -

Before I undertook all that work, I'd get a new, quieter unit. I have
a 25 year old unit located in the basement and most of the noise in
the living space comes from the head unit that sounds similar to a
conventional vac, not the motor in the central vac.

Would it be easier to use the vac when people are awake?

That said, you can use a bathroom exhaust fan, to draw the
heat from the top of the room / closet where the vac
resides. Also, please consider that the sound may be going
out the bottom of the vac through the floor. So, lift the
unit and put sound deadening under the unit.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Robert Green" wrote in message
...
I want to truly silence my Hayden central vac. I bought a
muffler for it,
but it's not really of much use since I've already vented
the exhaust to the
outside via an unused dryer vent. The facts are that it's a
high RPM motor
and it whines and wakes people up when it's in use when
someone's sleeping.
My plan is to box it inside something lined with acoustical
foam and to
provide two auxilliary fans (one low mounted push, one high
mounted pull and
thermal monitoring) to keep the motor cool and shut if off
if the
temperature in the box gets too high. I know the motor's
got a built in
thermal shutoff, but since I am going to be running it in an
abnormal
environment and what a replacement costs, I'd feel safer
with two.

I am going to make some preliminary and crude sound
measurements wrapping in
a different material to see if any has particularly good
sound deadening
properties. Anything I am missing? What sort of materials
(I was thinking
3/4" ply and that bumpy acoustic foam) should I use? How
much distance to
leave around the unit for good airflow? What CFM rate?
What sized fans? I
intend to use 120MM 12V PC case fans, but I'm worried that a
lot of sound
will leak out through the fan ports. I thought perhaps "top
hatting" them
the way chimneys and vent pipes are covered would reduce the
leakage,
especially if the cap had some acoustical foam facing the
fan.

Any thoughts appeciated. Any flames will be cheerfully
ignored!

Bobby G.

A central vac should not be making this much noise. Mine is in the garage,
in a 2x2x3 wooden box (no fans in box), vented to the outside with a 4"
duct. You cannot hear the unit inside the house at all, just the swish of
the air through the cleaner nozzle. Barely audible outside.

You should not need fans in your soundproofing box. After all, you do not
run your vacuum all day, maybe half an hour, unless you have a 10,000 sqft
house :-).

--
Walter
www.rationality.net
-
"Robert Green" wrote in message
...
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to
the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's
sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull
and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping
in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use? How much distance to
leave around the unit for good airflow? What CFM rate? What sized fans?
I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.

Robert Green wrote:
I want to truly silence my Hayden central vac. I bought a muffler
for it, but it's not really of much use since I've already vented the
exhaust to the outside via an unused dryer vent. The facts are that
it's a high RPM motor and it whines and wakes people up when it's in
use when someone's sleeping. My plan is to box it inside something
lined with acoustical foam and to provide two auxilliary fans (one
low mounted push, one high mounted pull and thermal monitoring) to
keep the motor cool and shut if off if the temperature in the box
gets too high. I know the motor's got a built in thermal shutoff,
but since I am going to be running it in an abnormal environment and
what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements
wrapping in a different material to see if any has particularly good
sound deadening properties. Anything I am missing? What sort of
materials (I was thinking 3/4" ply and that bumpy acoustic foam)
should I use? How much distance to leave around the unit for good
airflow? What CFM rate? What sized fans? I intend to use 120MM 12V
PC case fans, but I'm worried that a lot of sound will leak out
through the fan ports. I thought perhaps "top hatting" them the way
chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!


You may be trying to solve the wrong problem.

I'd put a timer on the electrical input so they thing won't even WORK during
sleeping hours.

There's also an innovative fix involving three items: Pliers, blowtorch, and
the person running the vacuum.

On Aug 15, 7:32*am, wrote:
On Aug 15, 8:20*am, ransley wrote:





On Aug 15, 2:24*am, "Robert Green" wrote:

I want to truly silence my Hayden central vac. *I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. *I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? *How much distance to
leave around the unit for good airflow? *What CFM rate? *What sized fans? *I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. *I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

Bobby G.

I would talk to Hayden , I bet they know what is most cost effective
and works. The Sound- frequency, frequencies, you are deadining have a
wave length that some materials absorbe better than others and foam
may not be as effective as something cheaper. An example of why you
only hear bass from cars or homes that are to loud is the wave of the
low frequency can be 3-4 feet long, and carpet stops the real high
frequencies *as they can be only 1/4" long. The frequency of the
whine, Hayden or a musician could figure out, then an enclosure needs
to be designed for that area of frequencies. I guess a 1" drywall box
with 6" fiberglass batts open to the motor might be better and cheaper
but i cant hear the vac from here, the fan idea and completely closing
it is risky, you cant rely on the thermal cutoff in their unit for
saftey. Maybe rubber mounting bushings of the vac would do alot as its
probably vibrating the wall.- Hide quoted text -

- Show quoted text -

Before I undertook all that work, I'd get a new, quieter unit. *I have
a 25 year old unit located in the basement and most of the noise in
the living space comes from the head unit that sounds similar to a
conventional vac, not the motor in the central vac.- Hide quoted text -

- Show quoted text -

Right I thought a main selling point is those were supposed to be
quiet, could the instal be bad? but I wonder if its really noisy.

On Aug 15, 9:54*am, "HeyBub" wrote:
Robert Green wrote:
I want to truly silence my Hayden central vac. *I bought a muffler
for it, but it's not really of much use since I've already vented the
exhaust to the outside via an unused dryer vent. The facts are that
it's a high RPM motor and it whines and wakes people up when it's in
use when someone's sleeping. My plan is to box it inside something
lined with acoustical foam and to provide two auxilliary fans (one
low mounted push, one high mounted pull and thermal monitoring) to
keep the motor cool and shut if off if the temperature in the box
gets too high. *I know the motor's got a built in thermal shutoff,
but since I am going to be running it in an abnormal environment and
what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements
wrapping in a different material to see if any has particularly good
sound deadening properties. *Anything I am missing? *What sort of
materials (I was thinking 3/4" ply and that bumpy acoustic foam)
should I use? *How much distance to leave around the unit for good
airflow? *What CFM rate? *What sized fans? *I intend to use 120MM 12V
PC case fans, but I'm worried that a lot of sound will leak out
through the fan ports. *I thought perhaps "top hatting" them the way
chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

You may be trying to solve the wrong problem.

I'd put a timer on the electrical input so they thing won't even WORK during
sleeping hours.

There's also an innovative fix involving three items: Pliers, blowtorch, and
the person running the vacuum.- Hide quoted text -

- Show quoted text -

Yea blowtorch the person running it at 2am

"Robert Green" wrote in message
...
I am going to make some preliminary and crude sound measurements wrapping
in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use?

I would use lead. You can get thin sheet lead in 1/32" that you can wrap
around the noisy box and kill all of the sound.

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.

On Aug 15, 12:39*pm, "Roger Shoaf" wrote:
"Robert Green" wrote in message

...

I am going to make some preliminary and crude sound measurements wrapping
in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use?

I would use lead. *You can get thin sheet lead in 1/32" that you can wrap
around the noisy box and kill all of the sound.

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent..

Heavy carpeting works wonders, the stuff with a thick foam backing
helps the most at the lower frequncies. I'd also contact the mfgr and
see if they could tell you of other installations of your model in
your area. Then go listen to a couple of those to see if yours is
especially bad,

Robert Green wrote:
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? How much distance to
leave around the unit for good airflow? What CFM rate? What sized fans? I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.



Buy a small jet engine, mount it on a stand outside the house
and run it at the same time as the vacuum cleaner. No one will
notice the noise from the vacuum cleaner.

TDD

stuff snipped

"RBM" wrote in message
...

Make sure your box will come apart, so you can empty the thing

That's a good idea and one I am ashamed to say I didn't put in my sketch!

Thanks!

--
Bobby G.

"ransley" wrote in message
...
On Aug 15, 2:24 am, "Robert Green" wrote:
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to
the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's
sleeping.
stuff snipped

I would talk to Hayden , I bet they know what is most cost effective
and works. The Sound- frequency, frequencies, you are deadining have a
wave length that some materials absorbe better than others and foam
may not be as effective as something cheaper. An example of why you
only hear bass from cars or homes that are to loud is the wave of the
low frequency can be 3-4 feet long, and carpet stops the real high
frequencies as they can be only 1/4" long. The frequency of the
whine, Hayden or a musician could figure out, then an enclosure needs
to be designed for that area of frequencies. I guess a 1" drywall box
with 6" fiberglass batts open to the motor might be better and cheaper
but i cant hear the vac from here, the fan idea and completely closing
it is risky, you cant rely on the thermal cutoff in their unit for
saftey. Maybe rubber mounting bushings of the vac would do alot as its
probably vibrating the wall.

Good points. Acoustics can be tricky. It's quite possible just wrapping
the motor end of the assembly will reduce noise enough to not wake anyone.
It's fairly quiet, and you can't really hear it if you're not near it except
when the house is very quiet. If I do my own fans, I will monitor the
internal temperature and kill power to the vac via relay if there's an
overheat. An extra thermal shutoff can't hurt much.

Thanks for your input!

--
Bobby G.

wrote in message news:6f54d0ce-95d3-4b77-aad5-

stuff snipped

Before I undertook all that work, I'd get a new, quieter unit.

I'll be waiting for your check! (-: I think you've got a point in that I
should try cheap solutions like a water heater blanket to see if that has
any effect. New vacuum not an option since this is new, sort of. Not very
many miles and was the top of the line at the time. It just sat in the box
a long time before the preliminary work got done. Who doesn't have such a
project waiting around their house?

--
Bobby G.

"Stormin Mormon" wrote in message
...
Would it be easier to use the vac when people are awake?

Shift work. Not an option. If the foreclosures ramp up, might even have to
"hot bunk" like they do on subs if homeless friends and relatives have to be
taken in. Let us pray for economic recovery. (-:

That said, you can use a bathroom exhaust fan, to draw the
heat from the top of the room / closet where the vac
resides. Also, please consider that the sound may be going
out the bottom of the vac through the floor. So, lift the
unit and put sound deadening under the unit.

It's hanging from a plate attached to a piece of 3/4 ply attached to cinder
block wall. I am moving it, so I think I will use some of the big
rubberized mounts I've seen in my junk pile but quite can't remember where I
got them from. Like car motor mounts, just much smaller. Good point,
though, to insulate the mountings as much as I can acoustically speaking.

--
Bobby G.

"Walter R." wrote in message
...
A central vac should not be making this much noise. Mine is in the garage,
in a 2x2x3 wooden box (no fans in box), vented to the outside with a 4"
duct. You cannot hear the unit inside the house at all, just the swish of
the air through the cleaner nozzle. Barely audible outside.

It's mounted in the basement and that makes all the difference, noisewise.
A high RPM motor of enough HP is gonna make noise naked to the world.
Mine's not yet in a box, either, so that's two major differences between my
install and yours and probably more than enough to make the difference,
noisewise.

--
Bobby G.

"Roger Shoaf" wrote in message

"Robert Green" wrote in message
...
I am going to make some preliminary and crude sound measurements
wrapping
in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use?

I would use lead. You can get thin sheet lead in 1/32" that you can wrap
around the noisy box and kill all of the sound.

But it would make Superman suspicious and we all know how he loves to crash
through cinder block walls when making an entrance. Good idea, but high
risk.

I never thought of lead as absorbing sound waves, but it absorbs other waves
quite well. I might look into acquiring a used X-ray apron. I'll bet that
deadens sound and a torn up one could be had for cheap with a little
searching. Thanks for the input.

--
Bobby G.

"hr(bob) " wrote in message
...
On Aug 15, 12:39 pm, "Roger Shoaf" wrote:
"Robert Green" wrote in message

...

I am going to make some preliminary and crude sound measurements
wrapping
in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was
thinking
3/4" ply and that bumpy acoustic foam) should I use?

I would use lead. You can get thin sheet lead in 1/32" that you can wrap
around the noisy box and kill all of the sound.

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.

Heavy carpeting works wonders, the stuff with a thick foam backing
helps the most at the lower frequncies. I'd also contact the mfgr and
see if they could tell you of other installations of your model in
your area. Then go listen to a couple of those to see if yours is
especially bad,

Another good idea. Thanks. I have some kicking around that I could try.

--
Bobby G.

Ah, shift work. I heard that. Having been a shift worker.

Mount on a foam pad is good idea -- camping section at
Walmart, buy a foam sleeping pad for six bucks or so. Cut it
up with a razor, to the right size for under your central
vac.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Robert Green" wrote in message
...
"Stormin Mormon" wrote
in message
...
Would it be easier to use the vac when people are awake?

Shift work. Not an option. If the foreclosures ramp up,
might even have to
"hot bunk" like they do on subs if homeless friends and
relatives have to be
taken in. Let us pray for economic recovery. (-:

That said, you can use a bathroom exhaust fan, to draw the
heat from the top of the room / closet where the vac
resides. Also, please consider that the sound may be going
out the bottom of the vac through the floor. So, lift the
unit and put sound deadening under the unit.

It's hanging from a plate attached to a piece of 3/4 ply
attached to cinder
block wall. I am moving it, so I think I will use some of
the big
rubberized mounts I've seen in my junk pile but quite can't
remember where I
got them from. Like car motor mounts, just much smaller.
Good point,
though, to insulate the mountings as much as I can
acoustically speaking.

--
Bobby G.

Robert Green wrote:

I never thought of lead as absorbing sound waves, but it absorbs
other waves quite well. I might look into acquiring a used X-ray
apron. I'll bet that deadens sound and a torn up one could be had
for cheap with a little searching. Thanks for the input.

You'll never get an FHA approved loan...

On Aug 15, 3:24*am, "Robert Green" wrote:
I want to truly silence my Hayden central vac. *I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. *I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? *How much distance to
leave around the unit for good airflow? *What CFM rate? *What sized fans? *I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. *I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

Bobby G.

My father in law put his in the utility room. He had the forsight to
insulate the walls. He also installed the washing machine, dryer and
to his wife's annoyance the dishwaher in there.

I love it. You can sit down and wath TV or talk and dont have to
worry about hearing major appliances running.

Jimmie

"JIMMIE" wrote in message
...
On Aug 15, 3:24 am, "Robert Green" wrote:
I want to truly silence my Hayden central vac.

stuff snipped

My father in law put his in the utility room. He had the forsight to
insulate the walls. He also installed the washing machine, dryer and
to his wife's annoyance the dishwaher in there.

I love it. You can sit down and wath TV or talk and dont have to
worry about hearing major appliances running.

Yes, that sounds like a great idea. Not to easy to do in a house that I am
only "making do" with until the real estate market regains its sanity. I'm
trying to get by until then. I think a foam blanket might easily do the
trick.

Thanks for the input.

--
Bobby G.

On Sat 15 Aug 2009 12:24:29a, Robert Green told us...

I want to truly silence my Hayden central vac. I bought a muffler for
it, but it's not really of much use since I've already vented the
exhaust to the outside via an unused dryer vent. The facts are that it's
a high RPM motor and it whines and wakes people up when it's in use when
someone's sleeping. My plan is to box it inside something lined with
acoustical foam and to provide two auxilliary fans (one low mounted
push, one high mounted pull and thermal monitoring) to keep the motor
cool and shut if off if the temperature in the box gets too high. I
know the motor's got a built in thermal shutoff, but since I am going to
be running it in an abnormal environment and what a replacement costs,
I'd feel safer with two.

I am going to make some preliminary and crude sound measurements
wrapping in a different material to see if any has particularly good
sound deadening properties. Anything I am missing? What sort of
materials (I was thinking 3/4" ply and that bumpy acoustic foam) should
I use? How much distance to leave around the unit for good airflow?
What CFM rate? What sized fans? I intend to use 120MM 12V PC case
fans, but I'm worried that a lot of sound will leak out through the fan
ports. I thought perhaps "top hatting" them the way chimneys and vent
pipes are covered would reduce the leakage, especially if the cap had
some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.

Bobby, the truly simplest approach is to relocate the unit outside the
living space. My parents had central vacuums in their homes since the
first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another possibility
would be the attic. At least half of those years I was living at home. I
could never tell when the unit was running unless I entered either the
garage, basement, or opened the closet.

It shouldn't be that difficult to run an inlet pipe to the new location, be
it through closets, hollow walls, etc. The other upside to doing this is
not tampering with the environment that the vacuum naturally requires. I
would never consider enclosing it in a box, despite the efforts to
ventilate it with fans.

--
Wayne Boatwright
------------------------------------------------------------------------
We are living in a world today where lemonade is made from
artificial flavors and furniture polish is made from real lemons.
Alfred E. Newman

On Aug 15, 2:24*am, "Robert Green" wrote:
I want to truly silence my Hayden central vac. *I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. *I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. *Anything I am missing? *What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? *How much distance to
leave around the unit for good airflow? *What CFM rate? *What sized fans? *I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. *I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

Bobby G.

Google motor and music studio sound proofing for ideas, the common way
to do music studios is a seperate wall of maybe 1" or more drywall
both sides with fiberglass batts, but it floats it doesnt touch the
other wall and its on rubber pads, moving it off the mounting you have
now may have a giant effect from stopping vibrations through block.
Sand inbetween 2 sheets of drywall is used for machinery, even an old
Bass amp of the 60s had sand. There is alot you can do cheaply, even
experimenting with hanging some carpet around it will let you see to
be its effect now so you can gauge results, who knows , an isolation
mount and carpet might do it. Radioshack sells cheap and good "db
meters" to measure sound volume.

On Aug 16, 12:57*am, "Robert Green"
wrote:
"JIMMIE" wrote in message

...
On Aug 15, 3:24 am, "Robert Green" wrote:

I want to truly silence my Hayden central vac.

stuff snipped

My father in law put his in the utility room. He had the forsight to
insulate the walls. *He also installed the washing machine, dryer *and
to his wife's annoyance the dishwaher in there.

I love it. You can sit down *and wath TV or talk and dont have to
worry about hearing major appliances running.

Yes, that sounds like a great idea. *Not to easy to do in a house that I am
only "making do" with until the real estate market regains its sanity. *I'm
trying to get by until then. *I think a foam blanket might easily do the
trick.

Thanks for the input.

--
Bobby G.

Does the unit have an exhaust pipe? I used to have a Kenmore unit in
the garage and even there it was bothersome until I extended the
exhaust pipe outside. When the motor on it finally went out I decided
not to replace it.

Jimmie

"Robert Green" wrote in message
...

Good idea, but high risk.

I never thought of lead as absorbing sound waves, but it absorbs other
waves
quite well. I might look into acquiring a used X-ray apron. I'll bet
that
deadens sound and a torn up one could be had for cheap with a little
searching. Thanks for the input.


High risk? The lead is not in contact with water, nor is it in a form that
will give you any grief from breathing in the area where installed.

Google lead soundproofing for details. The sheet lead would be a whole lot
easier than the lead apron and probably a whole lot easier to obtain and
use.

--

__
Roger Shoaf

Important factors in selecting a mate:
1] Depth of gene pool
2] Position on the food chain.

Wayne Boatwright wrote:

Bobby, the truly simplest approach is to relocate the unit outside the
living space. My parents had central vacuums in their homes since the
first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another possibility
would be the attic.

In an attic installation, how much performance is lost with an uphill
pipe run?

Robert Green wrote:
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to the
outside via an unused dryer vent. The facts are that it's a high RPM motor
and it whines and wakes people up when it's in use when someone's sleeping.
My plan is to box it inside something lined with acoustical foam and to
provide two auxilliary fans (one low mounted push, one high mounted pull and
thermal monitoring) to keep the motor cool and shut if off if the
temperature in the box gets too high. I know the motor's got a built in
thermal shutoff, but since I am going to be running it in an abnormal
environment and what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements wrapping in
a different material to see if any has particularly good sound deadening
properties. Anything I am missing? What sort of materials (I was thinking
3/4" ply and that bumpy acoustic foam) should I use? How much distance to
leave around the unit for good airflow? What CFM rate? What sized fans? I
intend to use 120MM 12V PC case fans, but I'm worried that a lot of sound
will leak out through the fan ports. I thought perhaps "top hatting" them
the way chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. Any flames will be cheerfully ignored!

Bobby G.

Go digging through some old dishwashers and remove the black heavy tar
like sheets of sound deadening material. (It's fairly expensive to
buy.) Now I'm not sure what would work better, putting this
soundproofing material on the outside of the vac, or on the box you
propose to built around it? I would think putting it on the outside of
the vac to be the best, and the messiest to do. Regular lightweight
foam won't do much, you need something with a lot of mass so it absorbs
the sound waves.

Bob wrote:
Wayne Boatwright wrote:

Bobby, the truly simplest approach is to relocate the unit outside
the living space. My parents had central vacuums in their homes since
the first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another
possibility would be the attic.

In an attic installation, how much performance is lost with an uphill
pipe run?

Even if it actually works, sounds like a lousy place to put it. You have
to haul the dirt back out through the house, and it is a pain to get to.
I'd probably never get a central vac (even if I won the lotto), but if I
did, I'd want it as close as possible to where the trash cans were, ie
the garage. I'd only consider the basement if it was a walkout.

Personally, I put central vacs in the same category as trash compactors-
a solution in search of a problem. Unless you a clean freak that vacuums
multiple times per week, dragging the vac around is simply not that big
a deal (especially since they aren't made out of heavy steel any more,
and modern super-magnets let them make the motors tiny). You already
have to shove the furniture around. But YMMV, of course. Only place
where I could see a central vac being useful, is in a wood shop, with
dedicated hoses at each tool station. AKA, dust collection system. But
those aren't really the same thing.

--
aem sends...

On Sun 16 Aug 2009 12:51:24p, Bob told us...

Wayne Boatwright wrote:

Bobby, the truly simplest approach is to relocate the unit outside the
living space. My parents had central vacuums in their homes since the
first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another
possibility
would be the attic.

In an attic installation, how much performance is lost with an uphill
pipe run?


I have no statistics, but I can't imagine much would be lost. I've know a
couple of families where their installation was in the attic. These homes
had no basements nor free space on the main floor. I don't recall anyone
mentioning a problem.

Consider that many, perhaps most, HVAC air handlers are in the basement,
yet the air easily reacheds the 2nd or even 3rd floor of houses. Perhaps
not a great comparison, but true nevertheless.

--
Wayne Boatwright
------------------------------------------------------------------------
There is no sincerer love than the love of food. George Bernard Shaw

On Sun, 16 Aug 2009 12:51:24 -0700, Bob wrote:
Wayne Boatwright wrote:

Bobby, the truly simplest approach is to relocate the unit outside the
living space. My parents had central vacuums in their homes since the
first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another possibility
would be the attic.

In an attic installation, how much performance is lost with an uphill
pipe run?

Are you joking, or just stupid?

"ransley" wrote in message
...
On Aug 15, 2:24 am, "Robert Green" wrote:
I want to truly silence my Hayden central vac. I bought a muffler for it,
but it's not really of much use since I've already vented the exhaust to
the
outside via an unused dryer vent. The facts are that it's a high RPM motor
stuff snipped

Google motor and music studio sound proofing for ideas, the common way
to do music studios is a seperate wall of maybe 1" or more drywall
both sides with fiberglass batts, but it floats it doesnt touch the
other wall and its on rubber pads, moving it off the mounting you have
now may have a giant effect from stopping vibrations through block.
Sand inbetween 2 sheets of drywall is used for machinery, even an old
Bass amp of the 60s had sand. There is alot you can do cheaply, even
experimenting with hanging some carpet around it will let you see to
be its effect now so you can gauge results, who knows , an isolation
mount and carpet might do it. Radioshack sells cheap and good "db
meters" to measure sound volume.

Good ideas. Since no one was home, at 2AM yesterday, I ran a test with the
basement windows open and I could clearly hear the motor from this sucker
two houses over, which is several hundred feet. Of course, late at night
(or the early AM) there are no other sounds so anything that makes noise
stands out.

I've set up an old laptop with CoolEdit audio shareware so that I can map
the sound frequencies to find out which bands produce the most noise. I
probably should get a real soundmeter, but the laptop's been giving me good
information, so far. My preliminary results are encouraging in that a lot
of materials I've tried deaden the sound noticeably, but I coming to the
conclusion that an enclosure made of sound deadening materials is the only
thing that's going to work effectively. I may, indeed, have an unnaturally
noisy installation, but there's not much I can do about it now other than
muffle it somehow. I am leaning toward a box with 3/4" ply exterior, some
type of sound-deadening insulation and then a layer of lighter plywood for
the interior layer, with that layer faced with eggcrate foam to further
deaden the sound. I could easily build it so that the "meat" of the plywood
sandwich could contain sand.

Thanks for your input!

--
Bobby G.

"Tony" wrote in message

stuff snipped

Go digging through some old dishwashers and remove the black heavy tar
like sheets of sound deadening material. (It's fairly expensive to
buy.) Now I'm not sure what would work better, putting this
soundproofing material on the outside of the vac, or on the box you
propose to built around it? I would think putting it on the outside of
the vac to be the best, and the messiest to do.

I tend to agree, but I am sure Murphy's law would cause the motor to fail
immediately if I attached soundproofing "schmutz" on the outside casing.
Hell, had someone not reminded me, I might have forget to add a service
hatch! (-: I do like the idea of acquiring some sound proofing from a
junkyard dishwasher. I'll have to search a little more in Google, Ebay and
other places to see what's available cheaply. Fortunately, nearly all the
sound "power" is concentrated at a few distinct frequencies, so I just need
to find sound deadening that's most effective for them. I'm liking the idea
of sand more and more because it's so cheap and a lot of sound energy will
get dissipated from the motion of the tiny sand particles as the sound waves
travel through it. My fear with sand is that it will compact over time and
fall away from the very top of the enclosure where the motor and most of the
noise resides.

Regular lightweight
foam won't do much, you need something with a lot of mass so it absorbs
the sound waves.

Correct. Wrapping a foam mattress pad around the motor was nowhere near as
effective as an old piece of heavy carpeting. I thought the foam would
absorb a lot more sound than it did, lending support to the lead and sand
methodologies. Today I'll go "sound mapping" again so I can report back
which frequencies are the worst offenders.

Thanks for the input, Tony.

--
Bobby G.

"JIMMIE" wrote in message news:6a9415f3-
stuff snipped
Does the unit have an exhaust pipe? I used to have a Kenmore unit in
the garage and even there it was bothersome until I extended the
exhaust pipe outside. When the motor on it finally went out I decided
not to replace it.

Yes, it's vented outside and through a Hayden muffler unit, but an awful lot
of noise still escapes. Worse, still, it's now pointed directly at a
neighbor's bedroom window. That's one of the reasons I am moving the unit
to the back of the house. The exhaust would then be pointing to my
backyard and the park beyond and shouldn't bother anyone.

Thanks for the input, Jimmie.

--
Bobby G.

"Wayne Boatwright" wrote in message
stuff snipped
Bobby, the truly simplest approach is to relocate the unit outside the
living space. My parents had central vacuums in their homes since the
first ones were introduced. There were three scenarios of their
installations. (1) Garage, (2) Basement, (3) Spare Closet, where the
interior walls of the closet were heavily insulated. Another possibility
would be the attic. At least half of those years I was living at home. I
could never tell when the unit was running unless I entered either the
garage, basement, or opened the closet.

I've lived with CV's for a long time, too. I live pretty close to neighbors
on each side and relocating outside my living space puts me closer to
theirs. In the interest of peaceful coexistence, I don't want to foist the
noise onto my neighbors, but to mitigate it as well as I can. That means
enclosure, as far as I can tell.

It shouldn't be that difficult to run an inlet pipe to the new location,
be
it through closets, hollow walls, etc. The other upside to doing this is
not tampering with the environment that the vacuum naturally requires. I
would never consider enclosing it in a box, despite the efforts to
ventilate it with fans.

Well, advice on "enclose or not to enclose" has been running all over the
map. Unfortunately I think it's the only option left considering all of the
issues. I'm hoping that several added safety interlocks will overcome what
I agree is the possibility that the unit might overheat. I'll be monitoring
the temperature in the box very closely. I also have a HomeVision
controller that I can set to make sure that the unit does not ever run more
than a set amount of minutes at a time and that the internal temperature of
the box never rises above a certain amount. A good friend says he doubts
the unit will even get noticeably warmer since the unit is always sucking
cool room air into the unit as part of the vacuuming process and the Hayden
CV design has that air flowing around the motor assembly.

Thanks for your input, Wayne.

--
Bobby G.

"aemeijers" wrote in message
stuff snipped
Personally, I put central vacs in the same category as trash compactors-
a solution in search of a problem. Unless you a clean freak that vacuums
multiple times per week, dragging the vac around is simply not that big
a deal (especially since they aren't made out of heavy steel any more,
and modern super-magnets let them make the motors tiny).

I respectfully disagree. No matter how high the filtration of a portable
vac, they output a considerable volume of air into the room that blows dust
around and around. They're terribly noisy as well, and that noise follows
the user around through the house, making it hard to hear music, the door
bell, etc. Most people I know that use central vacs would never think of
going back to a drag-around device. In the case of my unit, the horse power
is about 5 times that of a conventional vacuum and the suction much greater.
I can't imagine pulling the Hayden around on a cart. It's rather huge. CV's
improve the air quality of the home by removing 100% of the vacuumed air and
filtering it to the exterior of the living space and are great for allergy
sufferers. And there's no chance some temporary cleaning help like we had
when my wife got sick will decide to plug a vacuum into a UPS outlet and
start a small fire. (-:

We both love our CV, although each for different reasons. We ran through a
series of three Orrick cleaners before switching to a CV. The Orricks cost
nearly as much as the whole (uninstalled) Hayden system and so far, we
haven't even had to have the motor replaced once let alone three times as we
did with the Orrick. Vacuuming carpeted stairs is much, much easier with a
CV than with almost any kind of stand-alone vacuum. You can see the
difference when strong sunlight enters the room. Vacuuming with the Orrick
filled the air with so many dust particles it looked like a 3-D planetarium.
The CV on the other hand barely produced any noticeable increase in visible
airborne dust particles.

You already
have to shove the furniture around. But YMMV, of course. Only place
where I could see a central vac being useful, is in a wood shop, with
dedicated hoses at each tool station. AKA, dust collection system. But
those aren't really the same thing.

My CV is hooked up to my radial arm saw for just that purpose. Adding
another branch and outlet was a cinch and unlike the leaky shop vac I used
to use, the CV truly ejects dust without stirring up a lot of airborne
particles. Running a powerful standalone in a small room not only kicks up
loads of as yet unvacuumed dust into the air, it adds ozone from the motor
brushes and lot of extra heat into the room. The big downside is that I
will probably have to leave the CV as an "attached fixture" when we move
whereas we could much more easily take a stand-alone with us.

--
Bobby G.

Robert Green wrote:

Today I'll go "sound mapping" again so I can report back
which frequencies are the worst offenders.


The frequencies may change as you load the motor - go from sucking air
to pulling a vacuum.

--
bud--

"bud--" wrote in message
...
Robert Green wrote:

Today I'll go "sound mapping" again so I can report back
which frequencies are the worst offenders.


The frequencies may change as you load the motor - go from sucking air
to pulling a vacuum.

Interesting observation. The whining noise does change considerably when
something large enough to block the nozzle gets stuck without getting sucked
in. In that case, it's a good thing to be able to hear the increase in
noise and remove the blockage before the motor goes into thermal overload.
Lots of things to consider when boxing this bugger up!

--
Bobby G.

"Bob" wrote in message

In an attic installation, how much performance is lost with an uphill
pipe run?

Certainly you are working against the force of gravity and heavier objects
will stall going up a upward vertical intake instead of being helped along a
downward one. Who hasn't had to work a vacuum hose like a snake swallowing a
rat to get a stone or some other heavy object to move along?

While I do distinctly recall some discussion of how water lift (the
traditional method of measuring suction) was lower in "up to the attic and
down again designs," that could easily be because of the longer pipe runs
and the potentially greater number of leaks.


When I first looked into CV's I had to learn a whole new terminology to
compare units and estimate "suckiness" (in more than one dimension!). The
first oddball term was air watts, which at first sounds useful in evaluating
air guitars but is really an attempt to express suction power at different
nozzle diameters. Some CV accessories are air powered and put an extra load
on the system, hence the attempt by manufacturers to express the ability to
perform work with the air flow, giving us air watts. Anyway, what I
discovered was that a properly plumbed and sized CV system has more than
enough suction power to work from any location in the house.

I won't be mounting mine in that attic for reasons other than any possible
slight performance loss. Attic installations are not fun to service in
general, but the incredible heat genned in many attics leads to summertime
failures where you may encounter near-lethal heat, high humidity, wasps,
squirrels, bees and yes even ("who would hang all these teeny little black
bowties
upside down inside this closet?") BATS!!! That's why I would avoid the
attic and do.

But many folks are fine with attic installs, and since the installation
manual:

http://www.merchandisemecca.net/haydeninstallguide.pdf

(No affiliation, no recommendation, for all I know the worst virus in the
world will infest your machine upon visiting the site - use at your own
risk!!!!)

shows layouts for older homes where a single pipe ascends to the attic and
then comes down from above - an up and over design familiar to old house
rehabbers. So obviously it's not enough of a hit to be a serious issue. It
may be a blessing in disguise in that big heavy stuff is *less* likely to
get sucked into the main intake run because it would never rise high enough
to reach the attic run and might just fall out of the outlet at next
operation.

A much more serious set of performance robbing problems are leaky outlet
cover plates, poorly thought out pipe runs, very sharp bends, bad solvent
welds and burrs left on the inside of the pipe that catch the tiniest hairs
at first that eventually turn into full blown clogs. All of the branches
need to be designed with gradual sweeps and not elbows (except right before
the main intake on the motor unit) so that longish debris doesn't get forced
to make too sharp a turn and clog.

I thought CV installation was going to be just like drain pipe installation
but it was quite a bit different. All piping had to be cut with a tubing
cutter and then sanded out to make sure there were no rough edges. Since
it's a pressurized system, I didn't have to pay attention to pipe slope.
Vacuum piping has a much thinner wall and lighter couplings than similar
sized drain pipe which surprised me. I thought that they both used the same
type of pipe but I was wrong. When my unit is sucking sawdust generated by
the radial arm saw, no one can do any vacuuming elsewhere because the vacuum
level is too low if more than one outlet is active. I could get around that
if I were willing to add a second motor unit the way water heaters are
ganged together. Not likely!

Even during operation, I never run the hose without some sort of narrower
nozzle or attachment on the end to keep as many nasty things as I can from
clogging the hose (most of the time) or the pipe (much larger diameter than
the hose, so happens very rarely).

As far as bang for the buck, aside from the noisy motor unit, CV is great.
No motor whine in the same room you're working in, no blown-up dust swirling
around your head from the output air. That's all piped outside along with a
few million dust mites and the carcasses of their fallen brothers.

--
Bobby G.