RV / vehicle exhaust courtesy

[EB]

I have made a box for my Honda EU Genny out of furnace filters - it works well but it needs to have the playa kicked out of it occasionally.

Mojo, would love to see pictures of your EU box if you have them!

[phil]

> Please be courteous to your neighbours and attach some dryer/
> ducting tubing to your exhaust pipe

and run it back into your vehicle so you know what it's like having to live next to some jerkoff running his vehicle in camp. Same with generators: run the exhaust into _your_ tent/car/shade instead of mine.

Don't pitch your tent next to an RV

It's the other way around: Don't pitch your RV or generator next to a tent. Please.

[Mosin]

I think can settle the difference easily. Who arrived first and set up? They are staying.

[capjbadger]

> Please be courteous to your neighbours and attach some dryer/
> ducting tubing to your exhaust pipe

and run it back into your vehicle so you know what it's like having to live next to some jerkoff running his vehicle in camp. Same with generators: run the exhaust into _your_ tent/car/shade instead of mine.

Don't pitch your tent next to an RV

It's the other way around: Don't pitch your RV or generator next to a tent. Please.

It goes BOTH ways. If the tent is there, don't be an ass and park the RV.
If the RV is there, don't be stupid and put your tent there.
Easy.

Badger

[mojo]

I have made a box for my Honda EU Genny out of furnace filters - it works well but it needs to have the playa kicked out of it occasionally.

Mojo, would love to see pictures of your EU box if you have them!

I have not taken any photos yet but I'll try to shoot one this weekend.

I am surprized that the filters actually muffle noise as much as they do - I built it basically just to protect the genny and it does a fine job of that.

[Captain Goddammit]

I gotta bust some myths here.
I've owned more generators than I can remember, and have tried everything mentioned so far. I ran the exhaust into a barrel of water, originally trying to get a more realistic water-burble exhaust sound for my Land Yacht. The generator was fine with it, but it didn't get quieter.
I tried various car and motorcycle mufflers. It doesn't work.
The problem with shitty loud generators is that all the noise isn't coming out the tailpipe; the engine itself is radiating noise.

Those little Coleman 1850 watt sets are so goddamm offensive that if you happen to be next to me I'll run you a fucking cord rather than listen to it.
(Now THAT'S how to settle the loud genny argument!)

Your best bet is a soundproofed box rather than muffler changes, as long as you do have a muffler in good condition. The box is best when you need to redirect sound rather than eliminate it, because you can't fully enclose your genny, it needs air. Way back when, Esplanade theme camps used to set their generators out front, across the Esplanade, on the edge of the inner playa, in plywood boxes that were open on the back side (toward the playa, away from the camps.)

If you're surrounded on all sides, you're gonna be very unpopular if you insist on using one of those crap-can loud sets.

[ibdave]

Even the $149 Genturi system (which has a venturi opening at the base to avoid the excessive backpressure on your generator the dryer hose idea would create)

I have owned the Genturi for many years. We love it. No alarms being set off anymore. I use it at BM and use 2 honda eu 2000 as well...Quite is best...

[gyre]

I can't find any technical info on the Camco site.
Just because something is manufactured, doesn't make it a good idea.
There are a lot of intake and exhaust systems that are far worse than stock.

This inlet system is common is chimneys with a lot of heat, but in this case where there may be some question of having enough oomph to exhaust the fumes, it does seem to me it is counterproductive.
Heat is part of the power pushing the fumes out.
I suppose there is no harm if there is enough heat.
In all of these cases, it is not difficult to tell when it works or doesn't.
With a chimney, the intake venting is partially to ensure a draft in the case of partially burned fuel and primarily to cool the gases for safety.
Cooling exhaust fumes in an engine is a primary technique to reduce backpressure by shrinking the gases, but it also reduces the pressure to expel the gases.
This is rarely an issue for a car, but I could see it becoming one for a small generator.
I think they have done it in this case only to cool the gases.

I agree that many generators produce more noise and more importantly harshness, from the engine itself and not the exhaust pipe.
That's why encapsulation is called for on the best generators.
There are always diminishing returns.

Because exhaust systems are so easy to improve is a major reason why they are skimped on in many cases.
They figure that if it matters to you, you will dump the $30 muffler and get something better.
Or they figure if you cared, you'd buy a high end car in the first place.

Insulated exhaust systems are often touted for preserving the power on the flow, but in practice they are usually used to control massive heat in the engine bay.
I am told it is a bad idea unless the engine is tuned for this approach.
But I only have any knowledge about this approach in high performance applications.
There are production cars with conductive insulation around the exhaust system in the engine bay to reduce noise.
There will be some heat insulation with this approach but not a radical amount.

With the mild tune on most generators, I think you have a lot of flexibility in this area.
I think it's pretty easy to tell if you have backpressure issues with a design.

[Mosin]

Perhaps I take my comfort on the playa too seriously. I genuinely treat this trip like a mini Apollo mission, with as much proven reliability/redundancy as possible. Thus, for me, it is not enough to suppose, or to just think something sounds right based on conventional wisdom and/or speculation, or to be told something that I haven't tried out and tested myself.

If I did decide to wing it and show the original engineers what punks they are that would be my choice/freedom/pleasure, but I certainly wouldn't try to pass my speculation off as advise to others!

[gyre]

Naturally everything should be tested.
Do I need to say that?

Pretty easy to tell if an exhaust is better or worse.
There is plenty of past engineering to build on, and if a generator is too loud, you don't burn up in the atmosphere.


And harshness is not too be underestimated.
Flex joints are great for that.
Sometimes pleasant is better than quiet.

GM makes the cheapest crap on the planet.
When they couldn't solve a nvh problem with one of their cars, using all their engineers and their anechoic chambers and audio analysis, in desperation they added a flex joint to the exhaust system...and the problem disappeared.
They were just too cheap to put one in as God intended in the first place.
They never did single out the issue.

Flex joints ease the stress that causes early failures of systems too.
That's just one example.

Oh. NVH= noise vibration harshness

[phreakshew]

So I researched the hell out of this, reading all the comments here and on other forums and websites, and talked to other real live people also. I figured the best way to reduce the noise pollution on that generator (aside from turning it off) would be to build the 4 sided enclosure box out of soundboard, not plywood, 2 or 3 layers of boards deep, with a small space between each layer of boards. Basically, a box within a box within another box. From what I read, a small empty space between layers works better to absorb the sound than if those spaces were completely filled with foam or other insulating material. I figured I could put the whole shebang above everyone's lungs and ears by placing it on TOP of the van. This way the noise would be directed upwards and not out into anybody else's camp. A muffler affixed to the generator may or may not do much, but I don't think it would harm the generator. So, after planning this all out, I did what any other reasonable person in my situation would do:

I bought a Honda EU1000i generator on craigslist for $500. (HOORAY!)

That said, I now have a *brand new* small coleman generator for sale. First $200 takes it!

*sigh*

Thanks for everyone's thoughts and contributions on this! Also thanks to Captain Goddammit for offering the use of a cord - I don't think we'll need it now!

[gyre]

There are two principles involved here, absorption and isolation.

How would the boards be isolated from one another?
This is more important than the material used.

An inexpensive approach to sound barriers is dense sheetrock, plywood, soundboard, sheetrock and repeat.
It is important that the sheets be attached by a soft glue rather than nails.
Clips can be used for isolation instead of adhesives.
After the first series of each on a 2 by 4 wall, the next step is an isolated wall with no contact with the other.
It can be made of sideways 2 by 4s if space is a consideration, but it must be layered on the inside with sheetrock on both sides as an isolation wall or it will absorb sound and transmit it through.
The air gap can be small.
The solid walls need to have sound absorbing material in them.

It is easier to block sound than it is to absorb it.
Reflection is one technique.
This wall type uses reflection and absorption in differential materials to avoid transmission.
Absorbing sound tend to transmit it through the material.

A motor vehicle presents a different set of problems.
A generator needs to be isolated from the sound box and any transmissive material such as setting it on a truck.
High mass/density materials are good for isolation such as glass, lead sheeting, mortar board, dense sheetrock types.

My feeling is that gaps in a box as described would work better with fibreglass insulation.
But it may depend more on the design.
Since you are trying to stop a more specific set of sound patterns, gaps may act as a resonator and work more effectively empty.
It is not my expectation though.

Asphalt has proven to be a great sound material with engines and cars, fiber and asphalt (tar-like materials).
There are more sophisticated materials too.
Many involve pliable plastics and many layers.

[Captain Goddammit]

I did what any other reasonable person in my situation would do:

I bought a Honda EU1000i generator on craigslist for $500. (HOORAY!)

That said, I now have a *brand new* small coleman generator for sale. First $200 takes it!

You won't be sorry! You'd have been miserable with that Coleman.
Now you might wanna do this low-buck huge improvement to your Honda:

http://www.ilynne.com/captaingoddammit/

[ZaphodBurner]

Thanks for the reminder to pack the exhaust hose.

Our first year somebody pitched their tent right next to our tailpipe. We didn't even think about it. We were newbies and so were they, so they didn't think about it either. We turned on the motor for some reason and gassed 'em. No harm, no foul.

The next year we had a vacant 100x100' lot behind us, and some asshole put his tent not more than 6' from it, then had the nerve to get all aggro about the noise on the night of the burn, which was the only time during the week we actually ran it except when we used it building our public viewing platform. He disappeared Sunday morning with empty water bottles and a bag of trash left behind.

The trick is to be courteous and aware of the people around you, ask for advice or help if you need it, and don't panic if things don't go exactly as planned.

-c

[joemomma]

How often and for how long do you people run your generators? I can see large camps ..but isolated RVs?? Last year, my first, friend had a 5th wheeler and he ran his generator maybe 3 times in 7 days....
of course, we only used the camper to sleep, poop and pee... cold showers only 3x......

[Mosin]

We typically run our RV genny (6.5kw Onan which uses 3/4 gal per hr. under full load) for ~4 hrs a day, which runs the ac units for four of the ~six hours a day we sleep. This is the problem with staying up past sunrise every night (day?!) as you only get about an hour or two of sleep before it gets stuffy in the RV and we have to turn on the ac's. One benefit of this schedule is that we rarely piss off sleeping neighbors, as most tent campers are up by 9 AM due to the heat.

Side note: this year we will be cocooning the top 1/2 our RV in Reflectix in hopes of reducing the generator/ac use. If we get even one extra hour of sleep without the genny/acs it will be worth the $/effort.

[Captain Goddammit]

The last two or three times I went, I ran my Hondas continuously, 27/7 because I had A/C full-time and an electric fridge. I never had any complaints at all because I run quiet units, and even ran power to some neighboring people for lights, chargers, etc.
If I'm bringing it, I'm using it!

[ygmir]

I found a good deal on an older Kohler out of an RV, 4 kw.
It's pretty darn quiet, has forced air cooling using a squirrel cage fan for draw and the kicker is, it's propane powered. It doesn't stink at all, and, the fuel is under 3 bucks/gal.......

I built a fully enclosed box anyway, added swamp cooler fabric sprayed with wd40 for air intakes, and, ducted the cooling air straight up, and, the exhaust air is deflected into the same air stream. Pretty high velocity, so, it goes up and diffuses pretty well......
I hope it's quiet enough.......I know it doesn't really stink.......

[phreakshew]

hey I liked yer auxiliary gas tank idea, Captain!

We're on the same sleeping schedule as Mosin - It's dance dance dance dance - watch sunrise - pass out. Wake up 2 hours later dripping sweat. Not this year my pretties!

Because we now have the quiet generator, our box won't have to be so elaborate. But we still have time to experiment with some of Gyre's and others' suggestions...

[Captain Goddammit]

I'm not sure if this is what you're getting at, but... a Honda EU1000 won't run an air conditioner, especially at the high altitude of the playa where output is reduced 10 or 15%. You need two of them, or an EU2000.

[phreakshew]

We bought the smallest little window AC we could get:

It's only 515w. We ran it via the Honda 1000 for like 4 hours today.

Although, we are in the valley. It remains to be seen if it will run it at that elevation (what is that elevation anyway?) and in the extreme heat and dust.

Plan B is to bring a swamp cooler or a couple box fans just in case.

Would have liked to get the 2000, but even a used one is out of our price range right now.

[gyre]

Make sure you try it under a heat load.

It's 4000 feet more or less.

[we0ne]

I've had an RV there 2 years in a row and never ran the generator once.

[phreakshew]

So I found this on
[url]http://www.usdieselengines.com/how_alti ... rators.htm[/url]

Power Adjustment for Ambient Conditions:

Temperature, Altitude and Elevation can affect your generator power performance output. Use the following calculation adjustment factors to figure your generator power needs.

Temperature: Celsius: - 3% for every 10° C above 25°
Fahrenheit: - 1.5% for every 10° F above 77°
Altitude: meters: - 3% for every 300 m above 913 m
feet: - 3% for every 1000 ft. above 3000 ft
Altitude Note:
All generators give less performance at higher altitudes. Reduce the power rating on the label of the generator by 1% for every 1000 feet you are above sea level, 3% for every 1000 ft. above 3000 ft.

So assuming it's 107F and 4000 ft, then:
1.5% x 3 =4.5% & 1% x 4 + another 3% =7%

4.5% of 1000 watts = 45 (temp) +
7% of 1000 watts = 70 (elevation)=
wattage is reduced by 115 watts to 885 watts.
Right?

[phreakshew]

then I found this from http://www.homerepairforum.com/forum/hv ... ace-2.html

"The burst of energy required to start a motor is known as the “Locked Rotor Amperage-LRA). Once the motor begins turning it then draws “Full Load Amps- FLAâ€

[phreakshew]

[Captain Goddammit]

Those calculations are a little optimistic! The Honda EU1000 is rated at 900 watts, 1000 is it's "surge" rating, and the altitude is nearly 5000 feet.

[ygmir]

Good point:
The rating system for U.S. and overseas generators is different:

U.S. gens rate at constant load, overseas are rated at peak.
My Kohler is rated at 4 kw, and, will do that all day, peaking output about 4.6kw......
as you say, Honda will peak at 1Kw and run .9kw all day.
No biggie, just something to know when buying or planning.

[gyre]

Is it usa/imported, or is it like amplifiers, where there are the bullshit peak wattage ratings and the real ones?

The little fischer-panda is rated both ways, 6.8 continuous and 7.5 peak.
53 decibels at 7 metres too.
I think I want one of those.
They do have an intermittent dc charging generator too.
Looks like it would be louder.

[ygmir]

my experience is it's u.s./imported.
the imports are allowed to rate at peak, the U.S. must rate at constant service.......

Nothing wrong with it, it's just good to know......