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Topic: Ideas on quieting Onan Emerald III (Read 668 times) previous topic - next topic

Ideas on quieting Onan Emerald III

Just wondering if anyone has experimented with ways to quiet a propane fired Onan Emerald III.
The noise from ours seems to be the fan powered air intake. The exhaust is a lot quieter.
I keep thinking that every 90 degree change in direction supposedly reduces the noise about 50%.
Anybody tried anything? Besides new sound deadening material? Already done that.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Ideas on quieting Onan Emerald III

Reply #1 –
Quote from: nitehawk –
Just wondering if anyone has experimented with ways to quiet a propane fired Onan Emerald III.
The noise from ours seems to be the fan powered air intake. The exhaust is a lot quieter.
I keep thinking that every 90 degree change in direction supposedly reduces the noise about 50%.
Anybody tried anything? Besides new sound deadening material? Already done that.


Install a water cooled diesel gen set?  Trust me on this, you can get used to anything with enough time.  For me it's the thrumming in the floor.  I associate it with food: breakfast, lunch and dinner and maybe the after dinner movie.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Ideas on quieting Onan Emerald III

Reply #2 –
Hmm, I asked about ways to quiet my propane fired Onan Emerald III generator, not replace it.
I am having to balance cost vs the amount of time and usage we will get out of our coach.
The current generator only has 580 hours on it and I have had it out and replaced brushes and the end bearing.
It is not a matter of "getting used to it" but a consideration for other campers. The generator can be heard loudly thru the woods for at least 100 yards.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Ideas on quieting Onan Emerald III

Reply #3 –
As I said in my original post, the noise is from the air intake fan, not the exhaust. A few years ago (3?) I posted how I removed the generator, tore it down, cleaned it, replaced the end bearing, and replaced ALL the old black crumbling foam insulation.
The noise output (or input noise from the fan) is identical to the decibels out of Triple nickel's Onan generator. So, not just my generator but apparently the nature of the beast.
Just trying to ascertain if there is a way tl lower the intake noise.
I started to make an fan intake box that covered the louvers and will cause the air intake noise coming out of the louvers to have to change direction a "few" times. Obviously not something that could be hung on the coach permanently, but maybe in a CG.
I did do something like this when I was the head tool engineer at Mercury Marine in Fond du Lac, WI, and it worked.
I ended up doing a noise abatement study because the plant manager was standing next to an Acme Gridley bar machine when the six spindle magazine indexed 60*. He jumped all the way across a 6' forklift aisle!! Not bad for his age!
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Ideas on quieting Onan Emerald III

Reply #4 –
Quote from: nitehawk –
Hmm, I asked about ways to quiet my propane fired Onan Emerald III generator, not replace it.

It is not a matter of "getting used to it" but a consideration for other campers. The generator can be heard loudly thru the woods for at least 100 yards.

My Rockwood had a baffle behind the screen and my U225 has louvers in the door to keep the sound inside.  Any sort of labyrinth will reduce the sound level from the cooling air. If I were bothered by the sound of the cooling air I'd add a baffle to the inside of my door behind the louvers.

The first time I run out of propane dry camping . . .
With the Rockwood I could toss my 5 gallon gas can on the bike and ride into town to purchase gasoline.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Ideas on quieting Onan Emerald III

Reply #5 –
I remember that the dept built a communication center from a front wheel drive GM motorhome shell. An aircooled generator was installed with the foam with lead layers for sound insulation You could not hear in run inside when the it was done. Don't know if they sell that lead/foam insulation any longer.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Ideas on quieting Onan Emerald III

Reply #6 –
All right. Let's start over.
I'm not wanting to replace the Onan.
The noise doesn't bother me.
My concern is for the other folks in the CG.
The gen door already has five louvers in it and this is where the noise comes out, not the exhaust/muffler.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Ideas on quieting Onan Emerald III

Reply #7 –
My  Onan 5.5 is in a a quiet box .It is very quiet overall.

Re: Ideas on quieting Onan Emerald III

Reply #8 –
Quote from: nitehawk –
My concern is for the other folks in the CG.
The gen door already has five louvers in it and this is where the noise comes out, not the exhaust/muffler.
So my generator had sound absorbing mat and was applied over vents. It had fallen off and I pulled and removed all of it. Point I'm trying to make is that possibly you could cover louvers somewhat to absorb some of the sound. May even help if you opened up vents for louvers in mat.
There's lots of posts on it if you search. I've never used but will in future.
Amazon.com:
Scott