generator mufflers

[Lou]

Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
will be camping. Anyone have an idea on how to make my 70db generator
quieter besides not running it?
Lou

[john smith]

In article . com>,
"Lou" > wrote:

> Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
> will be camping. Anyone have an idea on how to make my 70db generator
> quieter besides not running it?
> Lou

Put it inside a foam lined box.

[Stealth Pilot]

On 14 Jul 2006 04:35:22 -0700, "Lou" > wrote:

>Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
>will be camping. Anyone have an idea on how to make my 70db generator
>quieter besides not running it?
> Lou

trade it in on a four stroke honda generator.

[Rich S.[_1_]]

"john smith" > wrote in message
...
> In article . com>,
> "Lou" > wrote:
>
>> Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
>> will be camping. Anyone have an idea on how to make my 70db generator
>> quieter besides not running it?
>> Lou
>
> Put it inside a foam lined box.

It will shortly overheat, seize and be very quiet using this advice.

Rich S.

[RST Engineering]

"Rich S." > wrote in message
...
> "john smith" > wrote in message
> ...
>> In article . com>,
>> "Lou" > wrote:
>>
>>> Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
>>> will be camping. Anyone have an idea on how to make my 70db generator
>>> quieter besides not running it?
>>> Lou
>>
>> Put it inside a foam lined box.
>
> It will shortly overheat, seize and be very quiet using this advice.
>
> Rich S.



Actually, it will run out of oxygen and stop long before it overheats.

Jim

[flybynightkarmarepair]

Lou wrote:
> Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
> will be camping. Anyone have an idea on how to make my 70db generator
> quieter besides not running it?
> Lou

Your approach will differ depending on your requirements. Are you
trying to make it quieter for you neighors or yourself?

Neighbors will be happier if your run the exhaust into a galvanized
bucket filled with water. The exhaust, via suitable hose (few are) or
flexible metal tubing. should extend BELOW the water level. There
should be a top on the bucket, vented around the edges to direct the
much reduced noise DOWN. ASCII art:

/--------------! !--------------\
/ ! ! \
\ ! ! / Exhaust exits bucket here
\_______!__!______/
\ ! ! /
\ Water /
\____________/

The lid should be as stiff as possible, or it will re-transmit the
throbbing.

If it's your sleep that's disturbed, you need to take other measures.
ALL transmission paths must be addressed. This means soft mounts for
the genset itself, AND soft connections for everything that attaches to
it. The barrier between the genset and the rest of the RV needs to be
stiffer, heavier, and more resilient.

http://www.soundproofing.org/ has lots of good advice, and products to
implement all these strategies.

[karel]

"Stealth Pilot" > schreef in bericht
...
> On 14 Jul 2006 04:35:22 -0700, "Lou" > wrote:
>
>>Ok, so it's not an airplane but it is related. I'm going to Oshgosh and
>>will be camping. Anyone have an idea on how to make my 70db generator
>>quieter besides not running it?
>> Lou
>
> trade it in on a four stroke honda generator.

or even better, for a couple of photo-voltaic panels

[karel]

"Morgans" > schreef in bericht
...
>
> "karel" > wrote
>>
>> or even better, for a couple of photo-voltaic panels
>
> That will be quite the photo-cells to run an air conditioner, and more.
> If
> it can't make me cool at night, why bother! <g>

For a nightly chill I recommend my first wife.

[Morgans[_3_]]

"karel" > wrote
>
> or even better, for a couple of photo-voltaic panels

That will be quite the photo-cells to run an air conditioner, and more. If
it can't make me cool at night, why bother! <g>
--
Jim in NC

[Ken Finney]

"karel" > wrote in message
...
>
> "Morgans" > schreef in bericht
> ...
>>
>> "karel" > wrote
>>>
>>> or even better, for a couple of photo-voltaic panels
>>
>> That will be quite the photo-cells to run an air conditioner, and more.
>> If
>> it can't make me cool at night, why bother! <g>
>
> For a nightly chill I recommend my first wife.
>
>

Was she adopted? I think I may have married her twin sister!

[Chief McGee]

I always wanted to put a big car muffler on my generator. If it can quite a
V8, it should work on a small one lunger. Anyone try this?

[Cy Galley]

You are dealing with sound pulses of a certain pattern and frequencies.
Large might not do as good a job as a muffler designed to the engine.


--
Cy Galley - Chair,
AirVenture Emergency Aircraft Repair
A Service Project of Chapter 75
EAA Safety Programs Editor - TC
EAA Sport Pilot
"Chief McGee" > wrote in message
news:Rmdug.838844$084.688499@attbi_s22...
>I always wanted to put a big car muffler on my generator. If it can quite
>a
> V8, it should work on a small one lunger. Anyone try this?
>
>
>

[Morgans[_3_]]

"Chief McGee" > wrote in message
news:Rmdug.838844$084.688499@attbi_s22...
> I always wanted to put a big car muffler on my generator. If it can quite
a
> V8, it should work on a small one lunger. Anyone try this?
>
It works, but not as well as you might think. They are made with the
resonance and flow rate of the bigger engine.

The exhaust running into a bucket of steel
--
Jim in NC wool would work better.

[Vaughn Simon]

"flybynightkarmarepair" > wrote in message
ups.com...
>
> Neighbors will be happier if your run the exhaust into a galvanized
> bucket filled with water. The exhaust, via suitable hose (few are) or
> flexible metal tubing. should extend BELOW the water level. There
> should be a top on the bucket, vented around the edges to direct the
> much reduced noise DOWN.

I'll bet the water muffler does well at reducing the exhaust note, (at the
expense of considerable back pressure) but you will be surprised at how much
noise those Home Depot class generators make that is NOT from the exhaust.
About the only thing that will quiet them down is a heavy, remotely sited,
generator shed.

If you really want quiet, those inverter generators made by Yamaha and
Honda are awesome. Expensive, but after all this is an aviation group. Money
is obviously no object, right?

Vaughn

[LJ]

Try two hub caps in the shape of a frizz-be(sp).Cut a hole in one cap
and weld it to the top of your exhaust pipe,weld the other cap one or
two inches above the first cap.You won't hear the exhaust.

LJ
Chief McGee wrote:
> I always wanted to put a big car muffler on my generator. If it can quite a
> V8, it should work on a small one lunger. Anyone try this?
>
>
>

[john smith]

In article
>,
"Vaughn Simon" > wrote:

> If you really want quiet, those inverter generators made by Yamaha and
> Honda are awesome. Expensive, but after all this is an aviation group.
> Money is obviously no object, right?

Vaughn, I am having difficulty finding a Yamaha generator dealer locally.
Yamaha's site is no help.
Is this something that is a regional commodity?

[Lou]

www.northerntool.com

[john smith]

In article om>,
"Lou" > wrote:

> www.northerntool.com

Thanks, Lou.

[[email protected]]

One other thing to do is check around the rental yards for a brand
called AGEKO? I belive. We used hundreds of their units in the refinery
during hurricane season. I could stand next to a 50Kw unit running at
full load and carry on a conversation with someone standing right next
to the unit and not have to have our voices much above a whisper. They
have the most sound deadened units that I've ever heard before. How
they do their units would be a good lesson on what works well.

Craig C.

[Morgans[_3_]]

> wrote in message
ps.com...
>
> One other thing to do is check around the rental yards for a brand
> called AGEKO? I belive. We used hundreds of their units in the refinery
> during hurricane season. I could stand next to a 50Kw unit running at
> full load and carry on a conversation with someone standing right next
> to the unit and not have to have our voices much above a whisper. They
> have the most sound deadened units that I've ever heard before. How
> they do their units would be a good lesson on what works well.

Did you read the decibels on that 3000 watt Yamaha? 57 db! Unbelievable!!
Light traffic is louder than that!

Most of the other brands operate at 67 to 72, with some as loud as 80 db.

They carry a nice price, but if quiet is important, those seem to be the
units to go with.
--
Jim in NC

[Vaughn Simon]

"john smith" > wrote in message
...
> In article
> >,
> "Vaughn Simon" > wrote:
>
>> If you really want quiet, those inverter generators made by Yamaha and
>> Honda are awesome. Expensive, but after all this is an aviation group.
>> Money is obviously no object, right?
>
> Vaughn, I am having difficulty finding a Yamaha generator dealer locally.
> Yamaha's site is no help.
> Is this something that is a regional commodity?

I recently bought two Yamaha generators for my employer from these people:
http://www.yamahagenerators.com/ and got excellent service. I agree that it
would be better to support a local dealer even if you pay a bit more, but my
search was as fruitless as yours. Even our local Honda dealer does not seem to
stock generators with any consistency, even though I live in a hurricane area.

Vaughn

[Rich S.[_1_]]

"john smith" > wrote in message
...
>
> Vaughn, I am having difficulty finding a Yamaha generator dealer locally.
> Yamaha's site is no help.
> Is this something that is a regional commodity?

John...........

After owning two Yamaha generators and one Yamaha Virago motorcycle, I can
say that starting the motors of all three is a continual problem. Neither of
the generators would fire without removing the spark plug and priming the
cylinder directly.

The motorcycle is an well-known abomination in the starting department.
Google "Virago starter" for 69,500 hits on how to fix the problems. Even
after these were well-known by Yamaha, they continued to manufacture this
joke of a starter for years. I would never buy another product from this
company.

I have had a Honda 5000 watt 120/240 volt generator for 7 or 8 years now.
Besides an occasional oil change it has required zero maintenance during
this time. It almost always starts on the first pull. Even if I am trying to
slowly pull it through to get some gas in the system it will start, scaring
the heck out of me. I give it my unqualified recommendation.

FWIW,
Rich S.

[Morgans[_3_]]

"Rich S." > wrote
>
> After owning two Yamaha generators and one Yamaha Virago motorcycle, I can
> say that starting the motors of all three is a continual problem. Neither
of
> the generators would fire without removing the spark plug and priming the
> cylinder directly.

That does truely suck. Too bad they can't get that fixed, because my 75
Yamaha bike was a good one.

> I have had a Honda 5000 watt 120/240 volt generator for 7 or 8 years now.
> Besides an occasional oil change it has required zero maintenance during
> this time.

My dad has had a Honda generator for almost 20 years, and it sometimes goes
2 or 3 years without being started. Even though it has not had any gas
treatment or any other special car, it starts within the first 2 or 3 pulls.
They are amazing, for their legendary easy starting.

The Honda generators are quite quiet, but they are nothing like the Yamaha.
As far as I could tell, nobody else makes one in the small to medium size
that is even half as quite. If Yamaha can do it, the others could, too.
They need to get with it!

So I guess you pick your poison. Quiet and hard to start, or easy to start
and loud.
--
Jim in NC

[Vaughn Simon]

"Morgans" > wrote in message
...
> The Honda generators are quite quiet, but they are nothing like the Yamaha.

I have not compared the exact specks, but both the Yamaha and Honda
inverter generators are very competitive and comparable, each manuvering for a
tiny marketing advantage on the other. I have a Honda EU2000i, and it is very
quiet. We have two 1000 watt Yamaha inverter generators at my shop and they are
also very quiet (and easy to start). Honda and Yamaha are to the generator
world what Honda and Toyota are to the auto world, you won't go far wrong with
either one.

Vaughn

[Morgans[_3_]]

"Vaughn Simon" > wrote in message
...
>
> "Morgans" > wrote in message
> ...
> > The Honda generators are quite quiet, but they are nothing like the
Yamaha.
>
> I have not compared the exact specks, but both the Yamaha and Honda
> inverter generators are very competitive and comparable, each manuvering
for a
> tiny marketing advantage on the other. I have a Honda EU2000i, and it is
very
> quiet. We have two 1000 watt Yamaha inverter generators at my shop and
they are
> also very quiet (and easy to start). Honda and Yamaha are to the
generator
> world what Honda and Toyota are to the auto world, you won't go far wrong
with
> either one.

Glad to hear that the Yamaha generator is east to start.

What is it about the inverter generators that makes them so quiet? Do they
run less RPM, or what is it? I have never been around one.

I am hesitant about an inverter, being the final drive. I had a 1500 watt
inverter that would not run the smallest 110 air conditioner that I could
find, even though it was rated as an efficient AC, and the amps rating
should have made it well under the rated output of the inverter. In fact,
the inverter was almost two times as big as what it should have needed to
be, according to it's rated output. I even put extra cooling fans to it,
and still, it would kick out with a thermal overload after about 5 or 10
minutes.

I also burnt out a power tool battery charger, even though I knew I was
taking a risk, according to the inverter manual. Most inverters have a
square wave output, instead of a sine wave output, and that will kill
chargers that run at a high voltage potential, until the load is attached to
the charger. So I am skeptical of inverters, unless it is sine wave output,
and the Yamaha inverter generator, looks to me, to be a square wave AC
output.

Anyone know what the waveform of these units are?
--
Jim in NC

[Vaughn Simon]

"Morgans" > wrote in message
...
>
>
> Glad to hear that the Yamaha generator is east to start.
>
> What is it about the inverter generators that makes them so quiet? Do they
> run less RPM, or what is it? I have never been around one.

Yes, they actually make DC and then feed it to the inverter. A normal
generator runs at 3600 RPM all the time. An inverter generator's engine only
makes enough RPM to make exactly the power needed to keep the inverter happy.
The less load, the fewer RPMs. You also save a bunch of gas since the engine is
not always revving its little heart out. Those little Yamaha 1000-watt
generators will run a refrigerator for about 12 hours on a single gallon of
gasoline.
>
> I am hesitant about an inverter, being the final drive. I had a 1500 watt
> inverter that would not run the smallest 110 air conditioner that I could
> find, even though it was rated as an efficient AC, and the amps rating
> should have made it well under the rated output of the inverter. In fact,
> the inverter was almost two times as big as what it should have needed to
> be, according to it's rated output. I even put extra cooling fans to it,
> and still, it would kick out with a thermal overload after about 5 or 10
> minutes.

It was a "Modified Sine Wave" inverter right? That is a big difference!
Refrigeration motors tend to start hard and run hot when ran with square wave
power. All inverter generators that I have seen so far use a true sine wave. I
have tried those little 1000-watt Yamahas on two different refrigerators with
excellent results. My 2000-watt Honda inverter generator barely notices my big
side-by-side refrigerator, but I have not yet tried it on an air conditioner.

Also, consumer refrigeration units tend to require a very large startup
surge compared to their "normal" running load. There are modifications you can
make to reduce that surge significantly.
>
>
> Anyone know what the waveform of these units are?

Like I said, all that I have seen so far are sine wave.

Vaughn



> --
> Jim in NC
>

[Alan Petrillo]

Vaughn Simon wrote:
> "Morgans" > wrote in message
> ...
>> The Honda generators are quite quiet, but they are nothing like the
>> Yamaha.
>
> I have not compared the exact specks, but both the Yamaha and Honda
> inverter generators are very competitive and comparable, each
> manuvering for a tiny marketing advantage on the other. I have a
> Honda EU2000i, and it is very quiet. We have two 1000 watt Yamaha
> inverter generators at my shop and they are also very quiet (and easy
> to start). Honda and Yamaha are to the generator world what Honda
> and Toyota are to the auto world, you won't go far wrong with either
> one.

Pardon my ignorance, but what is an "invertor generator"?


AP

[Morgans[_3_]]

"Alan Petrillo" > wrote

> Pardon my ignorance, but what is an "invertor generator"?

Most generators set the 60 cycles per second AC (alternating current, like
your house) power, by running the engine at a governed RPM. It is
different, depending on the brand, and how many different windings the
generator head has, but many times the engine runs at 3,600 RPM. They run
that speed, if you are powering a light bulb, or a big welder - same RPM,
wildly different loads.

An inverter generator has what is close to an automobile alternator, but
usually much bigger, and possibly different voltage. It puts out DC (Direct
current, like your car) power, but not what your appliances can use.

Added on to the DC output is a power inverter, which makes the voltage
change to AC, at an electronically controlled 60 cycles per second. If you
are running nothing, or a small load, the engine only is at idle, and making
enough electricity for a small load.

As you put larger loads on it, the inverter senses that it needs more power
for the big load, and brings the RPM up higher on the engine, so it is
making more HP, and sending more power to the inverter. It constantly
changes the RPM, making only what HP is needed to carry the load.

Some inverter generators even have a battery added in the generator, so when
you have a high surge load, like starting a motor or air conditioner
compressor, the battery takes care of sending the extra power for a few
seconds, until the starting load of the appliance is done. The end result
is a unit that has a more steady RPM of the motor, and it will be able to
run a larger motor or AC, because it has an extra weapon to use to take care
of the starting surge, rather than adding a larger engine.
\
That is the difference between the two Yamaha inverter generators that are
both 3,000 watt, but a couple hundred different in price, if you read the
fine print in the specifications.

I hope that is enough explanation, but not too much. It was a long one,
huh? <g>
--
Jim in NC

[Lou]

Jim, too bad you can't hear my applause. That was such a good
explination, I even understood it. Thanks
Lou

[john smith]

Sine wave, square wave and things inbetween.
It's all about the "area under the curve".
Tim "The Tool Man" Taylor always wanted "more power".
Sometimes, this is not a good thing.
The "power" delivered by cycle, be it square wave, sine wave or things
inbetween, can be found by calculating the area under the curve.
For a square wave, it is simple the width times the height.
A sine wave takes a little more math, but can be approximated by the
area under half a circle ((1/2)*pi*(r**2)).
These are greatly simplified for demonstration purposes.
Drawing a sign wave inside the square wave visually illustrates that
there is more power delivered by the square wave than by the sign wave.
This is why some devices heat up. They cannot handle the extra power
delivered by the square wave.
There are methods to reduce the area above the sign wave within the
square wave, but they complicate the inverter design and can add volume
to the packaging.
Pulsewidth modulation, an electronic means of making different length
square waves is an elegant solution, but adds cost and complexity.
Capacitor banks to build a stepped sign wave are more simple and less
costly but very bulky. The more steps desired to closer approximate the
sign wave, the more capacitors are required.
Like airplanes, power supplies are tradeoffs.

[[email protected]]

LJ wrote:
> Try two hub caps in the shape of a frizz-be(sp).Cut a hole in one cap
> and weld it to the top of your exhaust pipe,weld the other cap one or
> two inches above the first cap.You won't hear the exhaust.
>

That sounds very interesting.

But I'm having trouble reconciling "two hubcaps in the shape of a
frisbee."
with the second one welded "one or two inches" above the first.

Do you mean like this:

___
/ \
(gap)
\ _ _ /
| |
| |

(This will look beter with a non-proportionate font.)

--

FF'

[LJ]

Yes.You might experment with the gap. LJ

wrote:

> LJ wrote:
>
>>Try two hub caps in the shape of a frizz-be(sp).Cut a hole in one cap
>>and weld it to the top of your exhaust pipe,weld the other cap one or
>>two inches above the first cap.You won't hear the exhaust.
>>
>
>
> That sounds very interesting.
>
> But I'm having trouble reconciling "two hubcaps in the shape of a
> frisbee."
> with the second one welded "one or two inches" above the first.
>
> Do you mean like this:
>
> ___
> / \
> (gap)
> \ _ _ /
> | |
> | |
>
> (This will look beter with a non-proportionate font.)
>

[Morgans[_3_]]

"john smith" > wrote in message
...
> Sine wave, square wave and things inbetween.
> It's all about the "area under the curve".
> Tim "The Tool Man" Taylor always wanted "more power".
> Sometimes, this is not a good thing.
> The "power" delivered by cycle, be it square wave, sine wave or things
> inbetween, can be found by calculating the area under the curve.
> For a square wave, it is simple the width times the height.

That is why I asked about the wave form. I was assured it was sine wave. I
still wonder. Usually they are proud of true sine wave, and advertise it.
--
Jim in NC

[Morgans[_3_]]

"Lou" > wrote in message
ups.com...
> Jim, too bad you can't hear my applause. That was such a good
> explination, I even understood it. Thanks

Thanks. After all I am supposed to be a teacher! :-))
--
Jim in NC

[Morgans[_3_]]

"john smith" > wrote

> Sine wave, square wave and things inbetween.
> It's all about the "area under the curve".

> There are methods to reduce the area above the sign wave within the
> square wave, but they complicate the inverter design and can add volume
> to the packaging.
snip
> Pulsewidth modulation, an electronic means of making different length
> square waves is an elegant solution, but adds cost and complexity.
snip

The Yamaha is supposed to have pulse width modulation, which if it is fast
enough, can come pretty close to sine wave, I guess.
--
Jim in NC

[john smith]

In article >,
"Morgans" > wrote:

> The Yamaha is supposed to have pulse width modulation, which if it is fast
> enough, can come pretty close to sine wave, I guess.

Powerwise, yes.
As a sinewave arcs up to a peak then arcs down, the pulse widths become
progressively wider then narrower. The average of the area under the
curve approaches the power of of the sinewaveform. A simplified
approximation...
_ __ ___ __ _
| | | | | | | | | |
_| |_| |_| |_| |_| |_

[Vaughn Simon]

"Morgans" > wrote in message
...
>
> That is why I asked about the wave form. I was assured it was sine wave. I
> still wonder. Usually they are proud of true sine wave, and advertise it.

From the Yamaha site: "
a.. Inverter System with Pulse Width Modulation - Industry-leading system
produces higher-quality and cleaner electricity. Results in pure sine wave as
clean or cleaner than commercial power and can operate products with built in
microcomputers."
a..
Note the words: " Results in pure sine wave". Yes, it is pwm (just like any
sine wave inverter I know of), but the resultant waveform is far cleaner than
you will get from most any other generator, particularly from any other consumer
grade generator.

If you look closely at the specifications & instructions that come with cheap
generators, you will often see verbage warning you about operating sensitive
equipment. This is because they can have distorted waveforms, off-frequency
operation, and poor voltage regulation. (That said, they often manage to do the
job amazingly well.)

This conversation started about refrigeration motors which can be quite fussy
about waveform, but it is little understood that modern electronics have
switching power supplies that can be pretty insensitive to waveform. Strangely,
your computer is more likely to run well off of your cheap inverter than your
refrigerator, even though both of them may require about the same wattage.

Vaughn



> --
> Jim in NC
>

[john smith]

In article
>,
"Vaughn Simon" > wrote:

> This conversation started about refrigeration motors which can be quite fussy
> about waveform, but it is little understood that modern electronics have
> switching power supplies that can be pretty insensitive to waveform.
> Strangely,
> your computer is more likely to run well off of your cheap inverter than your
> refrigerator, even though both of them may require about the same wattage.

(I am trying to remember all this from college physics)
Think about how a refridgeration system "starts" and runs.
There is usually a "start-run" capacitor.
The capacitor is a "voltage" device.
The motor to run the compressor is a "current" device.
ELI ICE
Voltage leads current in an inductor (motor) by 90-degrees
Current leads voltage in a capacitor by 90-degrees

This has to do with the current and voltage phase with respect to each
other. This is really neat to watch on an oscilliscope.
Draw a picture of two sinewaves, shifted by 1/4-wavelength.
As you start up the compressor, the motor draws a slug of current, so
the sinewave current waveform distorts to look something like a sharks
fin. As the current gets sucked into the wires of the inductor, the
voltage collapses. The start-run capacitor dumps its stored voltage to
hold the line voltage up until the current draw diminishes as the
magnetic field is established. Then the capacitor draws a slug of
voltage to recharge itself, and the voltage waveform takes on the
sharkfin shape. And then the process repeats itself.
(Does that sound right to the experts out there?)