On 21 Jan 2005 03:26:18 GMT, the inscrutable Ignoramus1606
spake:
On Thu, 20 Jan 2005 21:58:03 -0500, axolotl wrote:
Ignoramus1606 wrote:
If only it was about combustion air. This is an air cooled genset that
requires a huge quantity of cooling air to cool the cylinder fins.
http://igor.chudov.com/tmp/onan/Diesel/
Oh boy.
The usual treatment is a serpentine air path lined with absorbent
material. You might try a box made of cement board with a serpentine
path (lined with rigid fiberglass insulation) in the front and back for
cooling air. I don't believe Sonex, Soundown or lead in an open box is
going to buy you much. The fix may end up to be a larger piece of
property and heavier electrical cable.
Thanks Kevin. I have some hopes that what I do will improve situation
somewhat. Specifically what is going to be behind the generator is a
high and wide deck. So, if I manage to redirect sound towards that, as
opposed to towards the front of the genset, my situation will improve.
It's better to muffle all sound than to try to redirect. If there are
trees (or neighbors!) in the direction of the redirect, they will be
sending some of that sound back, particularly in the higher freqs.
It's better to dampen it from -all- angles. It would also keep the
patio/deck nice to use all the time. Make sure you have the quietest
muffler system that the diesel will allow. I've heard they don't like
any backpressure at all.
I feel that some experimenting is educational, although there is some
point at which it will become more tiring than educational.
Want to try a low-cost solution? I've successfully used carpeting to
baffle noise from a compressor, primarily in the higher frequencies
but much of the lower frequencies were quieted as well. On something
that large, I'd try building a modified box at least twice its size,
(larger if you need exhaust cooling area) Spray a couple inches of
foam on the interior of each panel, then drape (old or new) carpeting
over the wet foam to form a triple skin, each with its own frequency
deadening attributes. You could later skin that with lead (and paint)
if needed. Alternatively, build double-walled shapes and fill with
foam, then tack carpeting on the inside. Indoor/outdoor carpet (as
thick as it comes) with foam backing, or used SHAG.
Top view of "box" showing venting between walls. Put carpet on the
outer side walls in inner passages (and floor/roof) for more sound
reduction. It's amazing how much noise it cuts by itself.
to deck
|===============================|===|
| | |
| | | genset | | |
| | | area | | |
| | | | | |
| | | | | |
| | | | | |
| | |
|====|==============================|
to home/shop
The long, tall side openings allow for full air flow.
-
Yea, though I walk through the valley of Minwax, I shall stain no Cherry.
http://diversify.com