Generator Noise

[TQUIN45]

Generator Noise

In the past several months I have had to take interest in Generator noise. Back in Aug my wife and I traveled from Mass. to the West coast and did a bunch of National parks. We were asked to shut down our generator because it was too noisy. Our generator is a Cummins Onan RV QD 3200 Diesel. It's output is 3200 watts. Winnebago uses these in their VIEW model. The Cummins noise specification is the noise will be less than 68 dBA at 10 ft and 1/2 load. I have measured (with sound power meter) the noise at 78 dBA which is 10X louder than spec. I spoke to other RV Views owners and theirs are also very noisy. At this point Winnebago will do nothing to help but Cummins has shown interest in helping. The other issue for people to be aware of the location of the generator exhaust- just behind the rear wheel directly under the awning and below the rear bedroom window. Being under the awning goes against all of Winnebago's safety notes- again they will not help by changing the location possibly out the rear of the coach. If anyone has any questions please ask. Note- Honda and Yamaha generators are usually below 58 dBA noise- worth noting if possibly going to purchase one. In my previous RV- a Winnebago Vectra our 8000 watt diesel generator was much quiter than the QD 3200 watt. At 10 ft you could barely hear it. From my experience up to this point be careful if you buy a Winnebago View with a Cummins Diesel generator. The big issue is Winnebago will not step up to the plate and try to resolve the problems of noise and location from the generator.

[j-d]

I agree with several points here.

-They're noisy
-Park Ranger can pretty much tell you what they want. Bottom line is "you can always leave." That's around the corner from "you'll have to leave."
-But they're sure helpful
-Agree 100% with the courtesy angle.

All that said:

-There are CG Quiet Time rules that should be followed.
-Outside those hours you (no, WE) should be allowed to run our gensets, particularly if they meet

Quote from Yosemite's CG Rules

***Quiet hours are from 10 pm to 6 am. Generator use is allowed only from 7 am to 9 am, noon to 2 pm, and 5 pm to 7 pm. Generator use is not allowed at other times.***

They don't allow genset use "all day" or "only outside quiet hours" which might not be known to everybody. They're allowing only those three two hour windows. Which should be enough.

I looked for the actual NPS rule and didn't find it. What I did see was the rule quoted on another site as "less than 60 dbA at 50 feet" which from the notes here seems pretty generously loud.

ONAN weighs in on this and quotes NPS with the same numbers

***According to the National Park Service’s current regulation, the A-weighted sound pressure level at a distance of 50 feet may not exceed 60 dB(A). ***

They go on to mention that their gensets meet the rules, but are louder close to the genset/RV.

[Dakzuki]

PJUSTICE2650 wrote:

I do not run my generator at any State or National park unless I need A/C, I than only run it during allowed operational posted hours.
We depend on our 12Volt system for all our night time needs. I find it a courtesy to other campers to opeate my Motor Home in that manner.

Amen, brother. When I was at Yellowstone this spring, they were doing some work with chain saws in the park so guess what I did? Yep, I cranked up the generator. I felt like a jerk running it any other time, it was so quiet in the park.

[Deleted-3]

TQUIN45, Phil Here. Reg: Generator noise. I have a Onan 4K gas generator in my Minnie Winnie, It makes noise! It makes more noise than a Propane gen. and less noise than your Diesel gen, that is just fact.

I do not run my generator at any State or National park unless I need A/C, I than only run it during allowed operational posted hours.
We depend on our 12Volt system for all our night time needs. I find it a courtesy to other campers to opeate my Motor Home in that manner.

You did not state at what hours you were running your diesel Gen.
But I will tell you that in my vast travel around this beautiful country of ours, I have noticed Park rangers shutting down these type generators at any hour. It is there discretion.
I have a friend of mine who applied a Propane 'sticker" on his Diesel generator and gets away with pointing to it when the ranger comes by, I tell him he is a dirty bird and God will get him for that action.

Pardon my spelling, My spell check is down

2004 22ft Minnie Winnie Chevy 6.0 V8 Phil Justice

[Dakzuki]

I have the same generator in the same RV. The exhaust routing is dumb. On the LP version they route it out the back which is a common mod for those with diesel generators.

Regarding the noise, you cannot compare it with larger diesel generators that are water cooled. The water jacket makes a great sound insulator. I have a 24 HP Yanmar excavator that's almost as quiet but it's water cooled. Another issue with the Winnebago is the vibration from the generator excites the structure of the RV which seems to make everything louder. This one I peg on Winnebago but they make no claims about how quiet their generator installation is so buyer beware. One thing I have noticed is just letting the bin door in front of the generator hang loose makes it a bit quieter. I may put some sound insulation on the back side of it and fill it with foam so address that.

My main solution is to use a portable Honda for battery charging. I will be adding solar is I dislike generators in general.

There is another thing I know of that two people have done. The replaced the OE generators with permanently mounted portables. One is a Honda 3000 and the other is a Yamaha 2400. The guy with the Honda has a 12 gallon fuel tank for it so it will run a long time. He says it's super quiet and of course weighs less that the LP unit he replaced. If it's any consolation the LP unit isn't terribly quiet either I'm told.

[rvten]

mikeleblanc413 wrote:
I have a Cummins in my 2000 Winnebago Minnie Winnie...it's an RQ...don't remember the model number...I don't have issue with the sound...I would like to know where I could buy a sound meter and the price range I could expect to pay.

If you have a smart phone. There is an APP with a noise meter. I use it.

[mikeleblanc413]

I have a Cummins in my 2000 Winnebago Minnie Winnie...it's an RQ...don't remember the model number...I don't have issue with the sound...I would like to know where I could buy a sound meter and the price range I could expect to pay.

[hotbyte]

When we tailgated some football games, I made up a Genturi type device to get exhaust up and away from area around MH. It seemed to make the running generator sound quieter...might have just been my imagination. If exhaust is under awning, using a genturi might prevent you from opening awning unless you could get genturi just to side of the awning.

And, as mentioned already, a national park will have restricted hours. You didn't mentioned if running during the allowed time or not.

[joe_b_]

If the exhaust location is a safety issue, then fix it and argue with the manufacturer about getting reimbursed for the cost. Don't believe I would use it if I really felt it was a safety issue, warranty or not.

The two different generators an 8KW and a 3.2KW have different engines. Some of the diesel pushers have the generator up front in a much better sound box. With the View having it back under the living area, it is bound to be more noticeable on sound and vibration, I would think.

Is the 3.2KW in the View water cooled? I am sure the 8KW was and that will make a big difference. A friend of my bought a small air cooled diesel generator, running a single cylinder Yanmar engine. Those engines are great and will run forever it seems, but the noise put off by it would wake the dead. He installed the Yanmar in an older Prevost, of all things but the noise was unacceptable and soon he took it out.

To me, generators tend to be obnoxious. I have had people tell me how quiet their generator is, that is exactly like mine, and all I can think of is they need to get their hearing checked if they think it is quiet. I have an Onan LPG in our truck camper now, and I have run combines, corn pickers and hay bailers that made less noise when operating. LOL

The number of cylinders will make a big difference. On our last two Class C units, one had a 4KW Onan and one had a 4KW Generac. The Generac was much quieter as I could never keep it running for the 80,000+ miles I hauled it around the country. Our last two gasoline Class As, one had a Onan twin cylinder 6KW and one had a single cylinder Onan 4KW. I believe the single cylinder put out twice the noise as did the twin. Why a twin or multi cylinder is quieter, I don't know but they sure are most of the time.

My Onan 2.5KW LPG generator, in the owner's manual, has the sound readings. In small print, it says something about those were the results of an independent testing lab. Does that mean, I am going to get the same sound level with the unit installed in my camper, not too likely. I am sure if I removed the generator and sent it back to the lab for the same tests, they would get the same results under the same conditions as it was originally done.

[rvten]

And at what time of day/night were you running the gen.?
This could make a difference in why you were asked to turn it off.

[TucsonJim]

Thanks for sharing. It's posts like this that help us what to buy in the future.

[Terryallan]

As a note of possible interest. I run the sound system at our Church. I use a DB meter to be sure it is loud enough. 58 DB is VERY loud. I try to keep the Pastor well under 60. A constant 70 will run you out of the building. As it is I get many complaints about the volume.

So you see. The so called quiet gen, ain't all that quiet. Especially in a really quiet atmosphere.