Onan 2800 is now quiet

[mojoman]

Just took DB readings, inside 52DB so my efforts lowered the noise compared to over 60db in a Travato. Now to work on the AC which is running at 56DB inside.

[wincrasher]

8 db is huge, so I'm interested in what you've done. Also, is this measured with the van sitting on concrete, or over ground? Makes a big difference.

[bobojay]

Details please....

[mojoman]

Its on my driveway with walls around, yes concrete. It should be quieter anywhere else.
The cover of the generator is covered with lead sheet and closed cell foam. I made a custom mount with 4 vibration isolators. The area around the generator is coated with ceramic beads and then closed cell foam glued to the underside of the floor. I also installed the resonator which helped a little. The floor inside is MLV sandwiched between closed cell foam.

I'm not done yet and I have some more ideas and hope to get the outside noise closer to 60DB within 5'.

[wincrasher]

Interesting. I've notice that most of the noise of the generator is coming from the cooling fan. How can you box that in, and still get sufficient cooling air? Are you monitoring your generator temps?

[mojoman]

My modifications didn't interfere with the cooling. Sound bounces off and transmits through hard surfaces, after I soften the remaining area under the generator area I plan to install sound absorbing baffles in the path of the cooling, so there is no direct path for the sound. since I have a lot of clearance under my generator, I can afford to loose a couple of inches with a flexible sound baffle. My van is not the Ext length so the generator is next to the axle and less prone to bottoming out.

[mojoman]

I added more sound absorbing foam around the generator and sprayed surfaces with spray rubber. It lowered the DB to 62db @ less than 20'. Softening the surrounding surfaces helps significantly.

[mojoman]

I finished installing 1/2" closed cell rubber under the van an all the flat areas, it further quieted down the generator while parked on concrete. Standing at the front of the van you can hardly hear it running.

[swo]

Originally Posted by wincrasher

8 db is huge, so I'm interested in what you've done. Also, is this measured with the van sitting on concrete, or over ground? Makes a big difference.

Having a devil of a time finding a place to install mine.
Both custom muffler and exhaust shop I called whined about having the right size clamps and hangers _ which I figured a custom shop would carry. Then I said if I got the hangers and clamps would they do the job. One said he wouldn't do it unless he could get it on his lift. The other said he had to see it first.
I'm all for the independent mechanics out there but what BS.

Maybe I need to go to MIDAS - I doubt they'd turn me away.

[mojoman]

Onan sells an exhaust kit that includes the ss flex pipe and hanger etc... You could do it yourself without lifting anything just laying on the ground. I made my own because I'm cheap.