Do I need a baffle box?

[jcliff]

I'm sorry if this has already been asked, but I couldn't find what I'm looking for. I have a new RV this year, and the generator was included. I bought both sight unseen, and they're being stored south of BRC. I'm understanding that I have to run the generator for an hour or two a day to keep the battery charged. The RV is going to be in my village, with neighbors all around. I've only seen pics of the gennie, and the mechanic that worked on the RV said it's running fine. However, I don't think it's one of the newer super quiet models. If I only plan to run it for a short time (I figured late afternoon would be best,) do I need to have a baffle box for it? There seems like a fair amount of anti-rv sentiment out there right now and I don't want to piss off my neighbors. Any suggestions?

[SageV]

It depends, is it an internal generator or an external one? If you have a generator that's separate from the vehicle, you should have it up on some kind of platform and baffled, ideally. If it's a generator that's internal to the RV, well that's understood its going to be a bit noisy. It's not unheard of to make artistic baffles that hide the generator's noise and are aesthetically pleasing.

[motskyroonmatick]

Can you show us a picture of it? Make? Model?

[Tiahaar]

this would work

or a piece of 3/4" plywood secured to a couple T stakes planted a couple feet from the RV, alongside the generator...works wonders.

[Canoe]

... or a piece of 3/4" plywood secured to a couple T stakes planted a couple feet from the RV, alongside the generator...works wonders.

Tweaked by egg cartons on the plywood.

Plywood deflects sounds upwards, while absorbing some of the sound - this is your biggest bang for the buck. You want it secure enough that it cannot get loose in the wind, but a little flex will absorb more sound energy. Painting the plywood means it will absorb somewhat less high-frequency sounds that bare wood, but it will shed water and the paint holds the wood fibers that otherwise would become MOOP. To contain splinters, tape the edges.

Adding corners to the sheet of plywood to extend the sheet back towards the generator/RV cuts down on the sound escaping around the ends.
\___/
Like cutting a 4'x8' sheet into 4' high pieces of 2', 4', 2', hinged and taped back into an eight foot long sheet. This also folds into a smaller 4' square section for storage. The seams/hinges must be taped to prevent sound escaping through any gaps at the join (a direct "line-of-sight" air path carries sound the best).
Adding corners also makes it self standing, but it still needs to be secured to the ground so it doesn't fly away in the wind.

Adding egg carton (of molded pulp cardboard; not foam) to the side towards the generator/RV breaks up and absorbs more sound. Also, less energy is reflected back at the RV where it can reflect back out at people. Easier and better than egg cartons from the grocery store, are egg carton flats (trays). These can be obtained free from restaurants or ordered new/guaranteed-clean online. The smaller squares are for holding 5x6 or 6x6 eggs (typically 11 3/4" square); there are larger flats holding 36 and even 48 eggs (16 1/2" x 13") available. A dab of glue (contact cement does well) on the inside peaks (the side that the eggs sit in) holds a sheet in place (you want the bottom of the flat facing the sound), or possibly nailed/screwed if your flat's cardboard is robust enough. Haven't done this, but you might be able to tape the edge between the flats and the plywood edge to keep dust out, and either tape or silicone seal to the seams between the flats (if you're intending to keep this for subsequent years).

After adding egg carton to the generator/RV side of the plywood, it may be quiet enough that you may hear the difference of adding egg carton to the outside of the sheet to break up retransmitted sound (sound energizes/modulates the plywood so some sound is retransmitted by the surface facing away from the generator/RV). But the relatively soft/flexible nature of the pulp cardboard has minimized this already so you're really into diminishing returns - but it can look cool painted...

Running the generator for two hours a day isn't too bad, but not at three in the morning. People also sleep in. Mid to late afternoon seems to be the least objected-to time to run a generator. If you haven't had an RV before, keep in mind that they need a deep cycle battery, not a car battery. In the Preparation - Keeping Cool thread "cooling your tent or van"
http://eplaya.burningman.org/viewtopic. ... 80&t=33842
they also talk about a recommended battery type from Costco, and recommendation on how far they can be safely/reliably used/run-down before being recharged. With one person, I only needed to run the generator for an hour every three days to recharge the RV battery (no idea on the power of the generator). Your results may vary.

[Bob]

To contain splinters, tape the edges.

With all due respect, that's like taping your crotch to contain stray pubic hair.

The baffling thing for me is why my camp neighbors last year with the brand-new shiny hexayurts were running repurposed air conditioners on a rusty old Coleman generator.

[Canoe]

The baffling thing for me is why my camp neighbors last year with the brand-new shiny hexayurts were running repurposed air conditioners on a rusty old Coleman generator.

For other stand-alone gensets (or on an RV), do you know where to find best-practices for a baffle box? Sure sounds like that one worked.

[Bob]

Hexayurts look like the perfect thing for containing a generator, actually.

[tamarakay]

Yes, yes you do.

Plywood cut to fit around it, carpet glued/attached on insides. Drill holes down sides, line them up with each other and you can either zip tie together or wire together. We wired on one side so we could unwire easily, open one side like a door to get in to fill gas, clean filters, start etc. we had extra carpet in the corners to keep sound from leaking out there.

easy peasy and your neighbors will really appreciate you.

[ygmir]

Yes, yes you do.

Plywood cut to fit around it, carpet glued/attached on insides. Drill holes down sides, line them up with each other and you can either zip tie together or wire together. We wired on one side so we could unwire easily, open one side like a door to get in to fill gas, clean filters, start etc. we had extra carpet in the corners to keep sound from leaking out there.

easy peasy and your neighbors will really appreciate you.

well, your neighbors appreciated you, because you are awesome..........but I'm sure the baffle box helped.

[Dr. Pyro]

We had a baffle box for our large generator three years ago that Crash made and wouldn't you know it, it set itself on fire. So since then we've done without and it's truly amazing: All those pesky neighbors moved on and now I have all the space I need.

[jcliff]

Thanks everybody! Baffle box it is.

[Canoe]

We had a baffle box ... and wouldn't you know it, it set itself on fire...

One way to get around the No Fireworks rule...

[theCryptofishist]

We had a baffle box ... and wouldn't you know it, it set itself on fire...

One way to get around the No Fireworks rule...

And I thought it was rebelling against the manditory trip to the back of the rv.

[ZaphodBurner]

However, I don't think it's one of the newer super quiet models. If I only plan to run it for a short time (I figured late
afternoon would be best,) do I need to have a baffle box for it? There seems like a fair amount of anti-rv sentiment out there right now and I don't want to piss off my neighbors. Any suggestions?

Ignore the anti-RV sentiment, but, do whatever you -safely- can to dampen the sound for your own camp's sanity. In our case he bought the RV without any sound dampening on the gennie, so when he ran it for coffee in the morning or to run power tools, it sounded like a somebody was working on a chopper.

It'll drive YOU crazy. He put a muffler on his and 50' or so away, you can't even hear it.

For portable generators, the only box you have to make is four plywood walls about twice as high as the generator itself, with 18" or so all the way around for ventilation. We tried different things, overheated a generator, massively over-engineered our attempt to make a quiet generator and left it off because it was too much of a hassle. On the last day, an uberveteran told us to try it with the top off the box, and it was ridiculous how simple and quiet it was. (It projects the noise straight up into the air and you barely hear it.)

[ZaphodBurner]

Hexayurts look like the perfect thing for containing a generator, actually.

Full enclosures don't dissipate heat very well and the generator starts running like shit unless you give it adequate oxygen. Plus, hexayurts are better spent living in, 'cause they're kind of awesome.

A simple wooden, open-top box as I described in this thread is the quietest and simplest of everything we tried. Naturally, we learned it from a much more experienced burner who solved a week of over-engineering in three minutes with a cordless screwdriver.

[EB]

If you get a Honda EU generator (or its ilk), no.

If you bring a cheapie, yes... but it won't help, IMO.

Honda's aren't cheap, but as Capn Goddamit would say: they're less expensive than a generator that sits dormant because you're too embarrassed to use. I think after "Stereo volume," "Generator noise" is probably the biggest friction-causer between neighbors and camping next to/with a cheap, loud generator is a serious bummer. Save yourself the nonsense of building a baffle and save up for a Honda.

There's some great threads on this very discussion but, alas, I am too stupid to use the search function to find them for you.

This post was brought to you by Honda, a proud sponsor of the "Shave Your Balls Now" camp.

[Bob]

Hexayurts look like the perfect thing for containing a generator, actually.

Full enclosures don't dissipate heat very well and the generator starts running like shit unless you give it adequate oxygen. Plus, hexayurts are better spent living in, 'cause they're kind of awesome.

Per my previous post, a camp neighbor running an old 100db Coleman generator and HVAC unit all afternoon and evening to move air through their more-airtight-than-thou hexayurt is most certainly not any kind of awesome. BTW, their baffle system consisted of a sheet of ply leaning against the generator, which *mysteriously* amplified the noise.

(Agree on the Honda.)

[Father_Burn]

Most of the noise comes out of the tailpipe. Get some properly sized flex exhaust tubing and clamps and a longer than your RV is high piece of metal pipe, and make a bracket to attach it to the side of your RV. Build a smokestack. Not only gets the sound pointed upwards where it will dissapate, but also gets the smelly part away from people's noses. Remember in your design that the pipe will get hot! Be careful of putting a baffle around your generator, as that will engourage Carbon Dioxide to seep into your RV. That could make for a really bad BM experience.

Good Luck!

[TinkerMom]

I used the same idea from playa tech furniture. The sides and top, all slide into each other.
There are holes in the black spots on one side, with screen, for air flow. And inside is
carpeted, for noise.

[Jackass]

Most of the noise comes out of the tailpipe.

Some of the sound may come out in the exhaust, but most of the loud generators I have seen are loud because the're old or just cheap garbage. Last year there was a camp down a ways from us that had one of "those". The damn thing was so loud that it was at least 100ft from any of their structures out by the road and surrounded by plywood. The noise that thing was making was the sound of metal rattling and also the engine was extremely loud. It was just a big, oversized, worn out piece of equipment that was probably on its last leg. Generators like that you can't do much to quiet down. Similar to the one pictured below...

gen.jpg

gen2.jpg

[Canoe]

... Carbon Dioxide to seep into your RV. That could make for a really bad BM experience....

Carbon Monoxide.
If you get a headache or look like a lobster, you've got trouble. Get out. Stay out.

[Father_Burn]

There's a generator in that picture?

[ApolloPan]

Though I hate to be a corporate shill, Honda makes the best generators. My father added a pipe to our exhaust, which is an excellent way to snake those pesky fumes away from you & your neighbors. Similarly, a simple box fan, set on top of an open topped baffle box can keep your heat down without amplifying your generator noise unduly. In a related story, my uncle -a contractor- had a neighbor who complained every time he made a sound at home. Uncle's solution: buying the LOUDEST generator possible to run in the afternoon. That would be the cheapest of open framed Colemans... Playa gremlins have been know to tinker with obnoxious, air-conditioning running generators. A deep cycle battery with an inverter with easily power a box fan for ya, FYI.

[Oldguy]

Solar car window fans can be hooked over the edges of box(s) also to stir the hot air out of a closed box.

[dragonpilot]

Be sure to place your generator well away from your camp...next to your neighbors'...

[gyre]

Jcliff, generators vary, as do rvs.

Many have integral damping boxes.
They can be added.
Start with the muffler and intake, if it's too loud.

Hondas are hardly the quietest or the best, but good for the money.

You haven't said which generator you have, or enclosure yet.