Generator noise reduction possible?

greyhoundtom · Senior Member

Generator noise reduction possible?

Gundog · Guru

An old trick we used in the army our Volkswagen powered generator that provided power for all the radios etc in an armoured command vehicle.

The end of the exhaust pipe was threaded, we had a length I flexible pipe that screwed on to it, at the other end there was a mesh container a bit like a Milo time with lots of holes in it.
the object was to bury the tin in a hole this became a secondary muffler.

A word of caution ensure there are no tree roots in the hole as potentially they can cause an underground fire.

Spydermann · Senior Member

Remember the etiquette (mentioned in many caravan & camping sites) about not running generators between certain hours. I'm assuming that if you are in a free site and everyone agrees to it, you could probably run one all night. A/C is one unit that would drain a solar powered battery.

Gundog · Guru

Spydermann wrote:
Remember the etiquette (mentioned in many caravan & camping sites) about not running generators between certain hours. I'm assuming that if you are in a free site and everyone agrees to it, you could probably run one all night. A/C is one unit that would drain a solar powered battery.

Tell me the difference between a generator and music in a free site.

It's a very subjective thing say, external speakers playing "Highway to Hell" or the 1812 overture at 11PM is greater than 100db and a generator @ 57db

what's the etiquette in relation to music, or jovial conservation, say happy hour turns into a BBQ which extends until after midnight, are we not there to enjoy the great outdoors, even human interaction is greater than 50db.

We live in a society that imposes the will of others upon you or we devise rules and call it etiquette, all to impose your standard on someone else, like it or lump it is your god given right to challenge someone else's standard if you don't agree with it, there is no reason to turn your generator off if you can effectively reduce the emitted noise level below 20db at 7m.

Gee I'm gunna get hammered on this

Cruising Cruze · Guru

Spydermann · Senior Member

Gundog. Must admit I've been told to keep the voices down especially when it's been a very clear night with no other noises and it's past 10 or 11 pm. That's why beer o'clock needs to be early in a campground. I think a good snorer probably makes the most noise, especially when in a tent or camper trailer.

Greyhoundtom. I reckon you may have issued a challenge here. Combining Sundog's suggestion with what I've seen done in the days when computer printers woke the whole office.

1. Sit the generator in a big box lined with some deadening material. I've seen pink bats, egg cartons , foam packaging with a pattern like egg cartons, the insulation that is used in galvanised sheds, and polystyrene foam from fruit boxes.
2. Run the exhaust thru a car muffler (cheapie but relatively new from a wreckers?)

You may even be able to get an old computer printer hood from a second-hand store. They usually have a fan that could run off the generator.

-- Edited by Spydermann on Tuesday 16th of June 2015 11:56:20 AM

Aus-Kiwi · Guru

Ours is built into motorhome .. I have fitted some sound insulation around its cubical . The exhaust is very quiet . Up close all you hear is cho cho about 8 meters away it's hardly noticeable .. Have some plastic like mud flaps that run longitudinal so noise is very quite on the other side . So I try to park generator side away from other campers.. It's amassing how many times campers have set up beside generator though!! No one has complained . Though it's never on late or early in the morning ..
When we go to Bathurst most the guys dig the mobile generators into the ground a few inches , the vibration seems worse than exhaust noise wise ? . It's the cheap 2 stroke generators which smell and give the good ones a bad name..
Yes we both ( thank goodness ) don't like humid conditions .. We run aircon to cool then turn it off as we go to bed.. With fan on ..

greyhoundtom · Senior Member

Thanks guys, some great ideas there. I will certainly do some experiments with a sound deadening box, fan, and additional exhaust system and see how I go.

)

Cheers,
Tom

Aus-Kiwi · Guru

Stainless steel scour pads is what I've used to inside muffler .. Offset chambers filled with stainless lasts longer than fibreglass which tends to fill with carbon .. 3" exh pipe (housing) with 1/2" inlet -outlet ( or the size of std exh) with welded in centre baffles ... Just have be aware of the carbindioxide build up where exhaust is etc..

-- Edited by Aus-Kiwi on Wednesday 17th of June 2015 12:23:50 AM

Kooroorinya Kelpie · Senior Member

Hi all. OP does'nt say what sort of airconditioner he wants to run but we run a Teco reverse cycle with a Honda 20i no trouble. Whichever method you use to reduce the noise level make sure you do not restrict the exhaust at all as any restriction will result in a burnt exhaust valve and costly repairs. I've lost count of the number of engines I've repaired over many years due to home made mufflers and Heath-Robinson noise reducers, all of which were next to useless. If you can get yourself a small, conventional type muffler, not a doughnut type, and mount that in-line with the existing muffler it will cut the noise down but not by very much. OP musthave a magic touch as the anti gennie brigade have'nt fired up. Cheers.

Cloak · Guru

One day hopefully in our lifetime silent fuel cells will be both decent output and affordable. I dream of zero noise power.

Last time I looked into them I got the impression they are a long way from matching a portable generator.

done dreaming · Senior Member

On a hot night if everybody put their aircons on and ran their gennies no one would complain except the ones without gennies who wished they did.We should show consideration to others but not be martyrs to others.

Leather Tech · Veteran Member

After deciding to hit the road fulltime and listening to nature ,birds,rain,insects,etc falling pine cones and gumnuts , I have made a conscious decision to embrace the gentle soothing hum of a modern quiet generator. ps I don't have one yet but I will if the need arises .

Dougwe · Chief one feather

Welcome to the gang Leather Techs, enjoy here and out in the playground.

Fastcoach · Senior Member

If you can't survive without the use of a generator, stay at home or in the nearest motel.

Kooroorinya Kelpie · Senior Member

Onya fastcoach, I knew one of the anti gennie mob would be unable to resist sabotaging an interesting and intelligent discussion. Generators are a fact of life so get used to it or, alternatively, make sure you camp in generator free areas. I have yet to see a post re generators which has not had a bunch of whining, selfish anti generator people whose narrow minded attitudes are vented on forumites ad lib. A 'live and let live' attitude will save you a fortune in antacids and blood pressure medication. Cheers.

Fastcoach · Senior Member

Gotta love your "shoot the messenger" 'tude KK. Lets turn all campgrounds into pseudo industrial estates, full of pathetic individuals who feel duty bound to ruin the experience of "proper" camping for the majority. Good for you!!!

blaze · Guru

my bitch isnt the generators with their steady hum but the old farts who insist on having their tele outside and not putting their bloody hearing aids in and they feel I need to listen to what they are watching from 50m away. The other one of couse is the extra happy hour that goes extendind time at many times the decibel level of a 2 stroke gennie. I use mostly solar panels but have been know to plug into a gennie. Tolerance is the key to harmonious camping no matter where it is with a touch of good comunication and a smile thrown in for good measure

Baz421 · Guru

Aus-Kiwi wrote:
Ours is built into motorhome .. I have fitted some sound insulation around its cubical . The exhaust is very quiet . Up close all you hear is cho cho about 8 meters away it's hardly noticeable .. Have some plastic like mud flaps that run longitudinal so noise is very quite on the other side . So I try to park generator side away from other campers.. It's amassing how many times campers have set up beside generator though!! No one has complained . Though it's never on late or early in the morning ..
When we go to Bathurst most the guys dig the mobile generators into the ground a few inches , the vibration seems worse than exhaust noise wise ? . It's the cheap 2 stroke generators which smell and give the good ones a bad name..
Yes we both ( thank goodness ) don't like humid conditions .. We run aircon to cool then turn it off as we go to bed.. With fan on ..

Great that you understand the principles of sound and know 90% of the time it's the need for sound attenuation (deadening) insulation of some kind, and pointing the exhaust away is also very considerate.

On my very noisy small home compressor I built a wooden box with removalists old blankets as an internal lining --- VERY EFFECTIVE.

HOWEVER, with gennys this may not be the best due flammability but the principle is there.

MY 2 worst experiences in the bush were a $150 cheapie running 18 hours a day - he came over next day to ask what it was like - I told him straight up, but he had power problems and did operate at reduced hours after that.

The other was a genny IN a box NO INSULATION and the sound from the aluminimum box was lousy,,, he was great inside his van as his rear wall shielded them,,, he thought he had the "best" set up,,,, but didn't understand sound transmission at all - AND WAS NOT BLOODY WELL INTERESTED EITHER,, a real inconsiderate pain in the ass. Very selfish attitude IMHO,,, no matter where you are,,, genny free/genny OK area,,, simply inconsiderate, plain and simple.

I'll duck my head now,,, so go for it.

-- Edited by Baz421 on Wednesday 17th of June 2015 11:43:01 AM

Ontos45 · Guru

Fastcoach wrote:
If you can't survive without the use of a generator, stay at home or in the nearest motel.

You mean to say then, that we, who need to use medical equipment for quality of life should give up the idea of traveling to satisfy your idea of tranquillity? Well, sorry mate, park near me and cop it sweet.

Baz421 · Guru

Maybe we need to "agree" on a standard sign(S),,, ie

I NEED TO RUN MY GENNY DUE TO xxxxxxxxx (could be anything critical if you are oK disclosing ie privacy issues)

I RUN MY GENNY AT TIMES TO CHARGE BATTERIES ETC -IT WILL BE OFF BY XXXXX (time)

I RUN MY GENNY TO WATCH TV - IT WILL BE OFF BY ,,XXXXX (time)

I RUN MY (CHEEP AND NASTY OR VERY QUIET) GENNY WHENEVER I FEEL LIKE IT.

This way we could chose whether to set up within earshot or not.

However it doesn't stop someone parking right next to us after we are set up. The worst was at Emerald camp area where,,, he was very good guy, BUT she directed (and I mean directed) him to park 2 m yes 2 m,,, no misprint,,, from our rear bumper (and set their table up 4 m from our door).

Anyway as I said in previous post I'll duck my head ,,, and log off,, I'll get the daggers tonight when I log on again.

Cheers Baz

aussie_paul · Guru

Fastcoach wrote:
If you can't survive without the use of a generator, stay at home or in the nearest motel.

That is a bit unfair Fastcoach...

Aussie Paul. smile

03_Troopy · Guru

I need to run a big Gennie to power the 200W RMS stereo amp I like to listen to Led Zeppelin on..

greyhoundtom · Senior Member

Found some interesting sound proofing material information from a company called Megasorber. Shall have to go to their office and see what I can obtain to build a suitable box.

http://www.megasorber.com/4fold-approach/sound-barrier.html

cheers, Tom

Aus-Kiwi · Guru

I use alu heat like www.ebay.com.au/itm/turbo-muffler-heat-shield-metal-exhaust-heat-shield-aluminium-heat-shield-/151559537445 I like the idea of using flame proof material..
I have also thought of routing generator exhaust into the motorhome exhaust ? 4" may be a little large though ..
I don't want to live like a bogan.. With out a geny ..

we insulated Rolls Royce engined generators for Sydney Elect supply authority ..

One thing to consider is heat build up.. Shields are way better than slabs of batts etc...

-- Edited by Aus-Kiwi on Wednesday 17th of June 2015 09:31:16 PM

Knowledge speaks, but wisdom listens.