"Doug Dotson" wrote:
"Ace-high" wrote in message
.. .
Suggest you buy a sound level meter from Radio Shack for $39 analog or
$49 digital and track down the hot noise spots and sound leaks - and
plug them. The irritation is either transmitted thru air - sound
waves, or solids - vibration. There's no other way. Use very soft
mounts. Or double mounts.
Good suggestions.
3600 rpm is harder to quiet down than 1800 - but you got what you got.
That's counter to what I have heard from manufactures of both types
of generators, and from my experience with my own 3600 RPM genset
vs a friend's 180 RPM unit.
It is all but impossible to shield a low frequency noise and the
corollary is that it is relatively easy to shield a high frequency
one. Low frequencies goes through solids. Think jackhammer type
noise. [We had a noise course where we had a tape of a jackhammer
which was placed in a trunk. When the tape was played we were
supposed to take sound level readings from in the room, outside the
room etc. We got complaints from people in adjoining BUILDINGS.] A
SLM from Radio Shack will only be an imprecise instrument to measure
noise - you would really need a octave band analyzer, but any kind of
meter is probably overkill. Just use your ears.
In addition to plugging up all the holes, you should make sure that
the surfaces surrounding the noise source are soft (not hard and
reflective) and bumpy. For instance if you have a cement block wall
that is unpainted, it will be better than one that is painted because
the paint fills in all the holes and reflects the noise back into the
room. A large piece of metal that might vibrate can be damped in
several ways, one of which is by piercing it.
We cruised for 5 years with a 7.5 KW Onan in our engine room under
center cockpit similar design to yours. It was noisy but worse -
unreliable.
Well, that's consistent with ONAN owners around here.
I've replaced it with a 6 kw Northern Lights 1800 rpm
genset with no sound shield as I like to visually inspect often. Vast
difference in noise created. The Onan had a very noisy air intake -
check this noise source out carefully on yours - and a 2 cyl clattery
engine.
Mine is a 1 cyl, but the air intake is a major source of noise. Mine has
a baffle that softens the noise greatly.
We had and still have 4 big solar panels - it's tough to find a good
spot for these - we moved them 3 times before finding a least
objectionable home.
We are facing the same situation.
We have 4 also - two on the foredeck under the staysail boom, one on
the dinghy davits and one on the radar arch.
We had a wind generator - noisy, vibrating and dangerous and high
maintenance - sold it - would not have one again. No matter who's.
SOunds like you bought an Air Marine. Too bad.
We have heard the same from folks that cruise in the tropics and near
tropics also. They do not like wind generators and take them off and
go exclusively with solar panels. We however like ours very well. It
works especially well at night when the sun doesn't shine and when it
is cloudy, which it sometimes is up here in the Chesapeake. It is not
dangerous or noisy, but it also does warn us when the wind is cranking
up.
When it's squall time at 3 am and the wind kicks up to 35 kts with
cold driving rain - who wants to go on deck to turn it out of the wind
and secure it. They all sound like a Cessna on the back deck trying to
do a short field takeoff. And they **** off you neighbors.
I just flick a switch from inside the boat to shut the wind generator down.
Better yet, the charge controller senses the high wind situation and shuts
it down automatically until the wind calms down to an acceptable level.
Swinging the mill by hand is both dangerous and archaic.
We don't have to go outside the boat either - the wind gen turns
itself off if the wind gets too high, or we have a switch inside that
we can turn it off when we are in a marina and don't want to disturb
our neighbors. Some neighbors are easier to disturb than others.
Some neighbors I'd like to disturb because they disturb me, but Bob
restrains me.
We'd like to have a genset for among other things to refill the scuba
tanks. What we have now is engine driven refrigeration, which we run
twice a day.
On Thu, 10 Jun 2004 16:09:40 -0400, "Skip Gundlach"
skipgundlach.sez.remove.this.and.the.dots.to.mail
wrote:
In several of the mailing lists of which I partake, there's been
discussion
of generators of late, originally about using AC, but migrating to
charging,
noise, space and cost considerations and other issues.
As we prepare to cut the cord for the rest of our lives, we're actively
considering an arch to carry solar and wind gear, as we'll be spending
the
rest of our lives in the Caribbean, where there's ample of both.
However,
the boat currently (pardon the expression) has a working generator of
recent
grandma Rosalie
S/V RosalieAnn, Leonardtown, MD
CSY 44 WO #156
http://home.mindspring.com/~gmbeasley/id2.html