"John B." wrote in message
...
On Sun, 16 Jul 2017 18:31:30 -0400, Neon John wrote:
On Sat, 15 Jul 2017 15:52:20 -0700, Larry Jaques
wrote:
Wow, 400 hours of work and you gave it away? I've always hated the
noise gensets put out, too. Compressors are bad enough, so I'm
working on a housing for mine now. (Project 143 or so on the
priority
list now.)
I hate the sound of running machinery. Because up here in the
mountains the power goes off for longer than 24 hours about every
month, I bought and installed Generac's 10 kW automatic standby
generator system. It works perfectly. EXCEPT. It uses a B&S
Vanguard twin cylinder air-cooled engine and a 2 pole alternator.
That
means 3600 RPM roar. Intolerably loud.
My interim solution was to buy 4 sheets of pre-fabricated wooden
fencing and 4 sheets of foil-backed Styrofoam sheathing and build an
open-top enclosure around the unit. I fabricated a duct out of
ductboard (compressed fiberglass) to carry the hot exhaust air up
and
out so the thing would not overheat.
That improved things a lot but the thing will still awaken me when
it
starts at night. Plus it's just a little too small. The automatic
transfer switch has 3 levels of load shedding. I have to shed the
water heater if the AC starts.
So I'm building the ultimate. I have procured a 15kVA foot mount 4
pole military surplus belt driven generator. And I've procured the
V6
engine, exhaust and electronics out of a late model Ford pickup
truck.
I used to consult to Ford on special projects so I was able to get
the
performance data on the engine and the PCM's source code.
The generator is an 1800 RPM affair. The performance data shows
that
the engine can provide about 25 HP at 1400 RPM. So the generator
will
be geared up a little. 1400 RPM is barely above idle on this
water-cooled and QUIET engine. And the Brake Specific Fuel
Consumption on that engine at that speed is phenomenal. I'll
convert
it over to propane but keep the emission controls. Nothing like
being
awakened in the middle of the night by the CO alarm going off
because
the air got heavy and trapped the current generator's exhaust.
This engine is fly-by-wire (servo on the throttle plate) so my
governor will be the cruise control. I've designed a little
microprocessor board that listens to the generator's frequency,
multiplies that by a factor to satisfy the PCM's road speed sensor
input and a few other things such as detecting power loss and
sending
a start signal to the PCM. The PCM controls the starter motor,
engaging it up to 5 times before locking out. The generator has its
own voltage control module.
This engine does not use an engine-driven cooling fan. All done by
giant pancake fans. Variable speed to boot. So little noise there.
The battery will be charged and maintained by a Progressive Dynamics
40 amp Intellipower so no generator noise.
The only remaining belt-driven accessory is the water pump. I'm
looking at a racing electric pump to replace it. Then there will be
only the 60 Hz alternator rotor that is turning.
The entire assembly will be housed in a small pre-fab building with
louvers to let air in and the radiators mounted over a hole in the
other side to exhaust air. I'm going to run 2 radiators in
hydraulic
series, located one above the other. I hope that with this
configuration, natural circulation will circulate the coolant and
require minimal pumping.
The inside of the building and especially the metal roof will be
lined
with spun lead as is used to soundproof sound booths. My goal is to
have this thing be so quiet that it'll be difficult to hear it run
even when nearby. I have a Generac QuietPack RV generator that
almost
meets that criteria so I think that it will be possible.
As the project stands right now, I've done all the procurement and
have written some of the code. The engine and generator will be
built
on a C-channel frame that is partially embedded in the concrete
slap.
I'm going to fill the concrete with about 300 lbs of #8 lead shot to
further help dampen the ringing.
My lung problem has rendered me slow and plodding so I figure I have
a
year to go on this project. I'll be putting progress reports and
photos on my blog, http://www.johndearmond.com.
John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address
Just as a comment, internal combustion engines emit a certain amount
of noise from the block itself and on sailing yachts it is quite
common to see the "gen-set" enclosed in an "insulated" box which
uses
sound insulation and in some cases even lead sheet to deaden the
noise.
See
https://www.linkedin.com/pulse/how-c...tor-sets-roode
--
Cheers,
John B.
I made a take-down sound reducing enclosure for a portable Coleman
generator from two 2' by 4' fire-rated acoustic ceiling tiles, cut to
2' x 2' since it's a small generator.
The faces of the tiles are fairly durable but the edges needed
sheetmetal channel rims to minimize crumbling. I had 2" wide steel
trim strips from an old aboveground pool and a brake to bend them on,
otherwise aluminum flashing bent around wood forms should do well
enough.
http://makezine.com/2015/06/24/skill...h-sheet-metal/
I prefer to hammer on a block of wood held against the bent flange.
This gives nice square corners.
The corners of the back panel are reinforced with aluminum angle
brackets that extend out far enough for the other three panels to nest
in for transportation and storage, mainly to protect the panels from
rubbing together.
It assembles with thumbscrews through the back that screw into
sheetmetal clip nuts in the rear corners of the sides. The top is
unattached for easier access to the generator, and the front is open
to let exhaust out and air in, a 4 sided cube. In bad weather it can
be covered with something waterproof like pieces of corrugated
roofing.
It faces back from behind the house, unfortunately toward possible
sound reflectors so I didn't measure the reduction in decibels, only
in how far away I could recognize it as a generator. I can't hear the
genny from the street or neighbors' houses if there's traffic within
1/4 mile.
While testing it I tried an exhaust extension of fiberglass pipe
insulation which barely made a difference, the noise comes from the
engine.
-jsw