Noise attenuation - undermount generator?

[InterBlog]

I’ve gone back about 5 years and cannot find any threads relating to LP generator mods.

We had to dismount our 16-year-old Onan 2500 in order to replace its internal hoses (rubber degrades!) and also the integrated regulator, the guts of which had disintegrated due to age, resulting in a dead generator.

If we were doing over this van from scratch, there is no way we would choose to add one of these generators, but years ago, it was a three thousand dollar unit and it still has low hours and we already own it, so we decided to fix it and put it back on. Additionally, during the February 2021 Texas deep freeze, we re-plumbed the van to accept external sources of propane, vastly increasing our future potential to use the generator, so why not?

We might as well incorporate as much noise and vibration mitigation as possible given that we now must reinstall it. We are DIYing that part of the job and currently evaluating what we want to add.

We have a muffler on order and will splice that into the exhaust line. There are a few other noise attenuation measures discussed on this Air Forums thread.

My question is, has anyone here on Class B Forum tackled the noise reduction goal, and if so, what were your mods?

Eleven-second video of our generator in the shop, cover removed. You can see all the new hoses - Cummins sells them in a kit complete with clamps and other hardware (no, my mechanic did not give me a part number for that kit, unfortunately - he ordered it). The regulator is that characteristic looking round thing on top with the orange and white label and shiny new bolts.

https://www.youtube.com/watch?v=J4o5eupTwJ0

[hbn7hj]

Add Dynamat above it and accept it. If you added the Onan muffler or resonator it doesn’t reduce noise any but it does make it easier to listen to and worth the install.

I mainly use the generator to run the A/C for a noon nap along a hot summer highway. Occasionally have run it all night to run the A/C to be able to sleep. The A/C itself is so loud the generator noise doesn’t matter.

I have run it after a 0F night to perk the batteries up in the morning. 100AH of lithium charges really quick so it doesn’t run long.

Eventually we will all install their new inverter generator, I think. Bottom line is I am not really bothered by the generator noise but I would like to have the new generator without brushes. Good hearing from you!

The status quo is never good enough for you, an admirable trait.

[hbn7hj]

Maybe Dynamat inside the cover. I suspect nothing you do will matter much.

[jjrbus]

I cannot understand how they have been selling Ohno generators to RV'ers all these years! I never appreciated the sound of a lawn mower running under my RV! I have been rv'ing over 20 years and have not had a Onan in 20 of them! I recently bought my Roadtrek and the first thing I did was remove the good running Onan and sell it! I have used Honda's and have had 2 fail to start, one was a blown fuse and one was a broken start cord. Neither of which cost me my first born to repair.

Using a suitcase generator is a pia and not for everyone. I also removed the AC and replaced it with a LG 9500.

[jjrbus]

This person is pretty good at explaining what is involved in quieting a generator. Not an Onan but the principles are the same.

https://www.youtube.com/watch?v=kuRd-ZPeaoQ

[InterBlog]

Originally Posted by hbn7hj

…..

I mainly use the generator to run the A/C for a noon nap along a hot summer highway. Occasionally have run it all night to run the A/C to be able to sleep. The A/C itself is so loud the generator noise doesn’t matter.

…
…

The status quo is never good enough for you, an admirable trait.

That’s also my primary generator usage - daily napping on the highway throughout our annual 6,000-mile cross-continent trip. The interstate highway system, where there is so much noise that the generator noise does not matter. That, plus emergency uses.

As for the status quo never being good enough, I call it continuous improvement.

Last year’s continuous improvement involved commissioning the build of this little trailer (pic below), on which we installed another 600 W of roof solar to go with the 300 W on the van. The trailer is not needed for typical trips, but if we are going for multiple weeks off-grid, we wanted the ability to expand. Among other things, the trailer carries my motor scooter which serves us in lieu of a toad, which makes grocery runs much easier because we don’t have to re-mobilize the van (it’s a 30-mile round trip to the nearest outpost which sells basic groceries - not a grocery store per se, but can get bread, eggs, milk, and canned goods which I can carry in my backpack). The trailer also carries my husband’s mountain bike which is very important to him.

You can also see that we mounted the mother of all telescoping masts on that trailer for our directional cellular antenna, which furnished an improvement but not enough to make me happy, so this year we are bringing Starlink, which comes with its own significant power demands.

Plus I bought an Engel MT45 portable freezer which will run off an EcoFlow Delta Pro, also to be carried in the trailer. And the trailer allows us to expand our collection of woodsman power tools which we need because Hurricane Fiona hit my property late last year and I have an unholy mess to clean up.

So my continuous improvement has substantially expanded my electricity demands, so the refurb’d generator can also be a fall-back for all of that. With the trailer, I can carry extra bottles of propane, so I’m covered on power redundancy.

All of this “continuous improvement” represents a significant financial investment, but I’m getting closer to retirement age, and this is the type of thing that I want to do in retirement, so with luck, it’s stuff that I will use for the rest of my life. I’d rather have these abilities than a larger more expensive stick-and-brick house.

[hbn7hj]

Welcome to Starlink. Hopefully the cross border thing won’t bother you. Your connectivity problems are solved.

We have used it for two years and have the round dish which appears to have fewer problems than the square one. It does have power supply reliability problems with no new ones available. I picked up two used ones. Should they fail I’ll have to convert to 12 volts.

Wifi calling works so well I get spam calls!

I have had an Engle 15 for 25 years and still going.

Keep it up and you will be into a diesel pusher! Just joking.
I did get a kick out of the iiquid nitrogen.

[InterBlog]

My husband bought the Starlink which was highly subject to availability. We have a cottage in rural Texas and we were waitlisted FOR A YEAR with no unit delivered to us for that address, because the original intention was to get the kind of plan that we could primarily use fixed in place (we currently have very expensive DSL there). But Starlink plans and scopes of service keep changing and it turns out that we had to abandon that endless waitlist and just get whatever was available, which is this 3rd generation dish, and all of those are apparently rectangular. I have not kept up with spec and plan evolutions - my husband made that decision.

[hbn7hj]

Kudos for knowing the rectangular dish is version 3, (There were two round versions.)
Ebay doesn’t know that and V2 is rectangular to them.

I am going to flat mount a V3 on a Roadtrek in October and will post with pictures when I get it done. Don’t need it to work in motion but I’d like to be able to stop and flip a switch to get it working, no setup.

They have an iPad size antenna in the works. That should be interesting if they ever sell it.

I have the dish and all the flat mount parts but don’t need it to work till fall.

My service address for the round one is Moab but I find it works fine for me with the lower priority or RV mode. I’m willing to share but usually neighbors don’t show any interest. In dispersed camping spots, where I usually stop, others are too far away to use it. I do have a way to broadcast it higher power but don’t bother.

[InterBlog]

And the Starlink draws about 40 W, IIRC. It was less viable for us before we had the trailer with its vastly expanded power capacity. We could have turned it on for short periods, but we have learned the hard way that every bit of software out there is predicated on an assumption of continuous connectivity. That’s what kills us on cellular - leaving computers off except while directly working, and then they become confused as soon as they are put back online, and they gobble up data in the background as a result.

My husband is a federal contractor and he doesn’t have control over how his work computer is configured. It’s not uncommon for that thing to gobble up 10 GB inside of 2 days on the road. And I ask, “What the hell is it doing and why can’t you get IT to make it stop losing its indexing such that it needs to keep transferring that much data back and forth to the server?!” And the answer is that the IT department has bigger fish to fry than to worry about one remote worker who is fighting cellular data limits. They don’t care.

It’s a mess, in other words. Hopefully it’s a mess that Starlink will fix for us.

I am curious as to how vanners carry Starlink if they do NOT have a trailer. The hardware is a large and inconvenient shape which does not fold compactly. I don’t know where I am going to stow it during shorter trips for which we are not taking our trailer.

[hbn7hj]

Originally Posted by InterBlog

I am curious as to how vanners carry Starlink if they do NOT have a trailer. The hardware is a large and inconvenient shape which does not fold compactly. I don’t know where I am going to stow it during shorter trips for which we are not taking our trailer.

The answer, of course, is on the roof.

https://star-mountsystems.com/

https://www.markertek.com/category/r...net-connectors

You cannot park under trees. Starmount prices seem kind of stiff but they do offer a solution. The mounting brackets come from AMSolar and somehow fit perfectly for a tape mount.

The pictures do not show a completed system because I have not done it yet.

The connectors do not require a crimper.

[avanti]

Originally Posted by hbn7hj

You cannot park under trees. Starmount prices seem kind of stiff but they do offer a solution. The mounting brackets come from AMSolar and somehow fit perfectly for a tape mount.

The pictures do not show a completed system because I have not done it yet.

I'm going to wait for the new, tiny dish. I would rather be able to park in the trees than to have the convenience of a roof mount.

[hbn7hj]

There is a quickly removable roof mount. You and other creative people can solve that problem.

No promises on the small antenna. There was just a news release that they had submitted it to the FCC for approval. Wear it on your hat!

Gotta be some signal strength issues.

[avanti]

Originally Posted by hbn7hj

There is a quickly removable roof mount. You and other creative people can solve that problem.

Yes, maybe. But, I picture only using it where there is no cell service, so hopefully not every night. I did save a space on my roof, though.

No promises on the small antenna. There was just a news release that they had submitted it to the FCC for approval. Wear it on your hat!

I've been following that as well. Looks real, but who knows when?

Gotta be some signal strength issues.

Well, yes. But as they keep launching more satellites, that issue gets reduced. Hoping that by the time I buy, it will be a non-issue.

[InterBlog]

Originally Posted by avanti

I'm going to wait for the new, tiny dish. ….

But… but… a tiny dish would not be able to accommodate as many cats!!



Our unit was delivered with a cat sticker, and I asked my husband, “What the actual freak is this?!” Upon which he explained the phenomenon.

BTW, this thread wins the 2023 drift award, but this doesn’t bother me or anyone else, because it’s all good information.

[JonMN]

I have been working on my year old Onan 2800i. While under the van I notice that the mounting system has some very effective rubber isolators. The mount essentially hangs on them. Sorry, but I could not identify the brand of the mount. Combining this mount with the internal rubber mounts of the new Onan makes for extremely low levels of vibration.

I did add the resonator that was mentioned earlier. It's not expensive, and kind of evens out the sound. I take this as a positive. For perspective, if the A/C is running you hear that over the generator inside or out.

Helps that I had a friend that could weld. You can clamp this too if desired.

[hbn7hj]

The Onan resonator gets rid of the putt-putt.