Jason
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Post by Jason on Dec 9, 2013 18:27:43 GMT 10
Even if you are miles away from anywhere the noise of a generator can be heard for a long distance. I cam across this interesting article about keeping the volume down on a genny and thought it was worth sharing: www.alpharubicon.com/altenergy/gensetquiet.htm |
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Post by Ausprep on Dec 9, 2013 18:31:12 GMT 10
Even if you are miles away from anywhere the noise of a generator can be heard for a long distance. I cam across this interesting article about keeping the volume down on a genny and thought it was worth sharing: www.alpharubicon.com/altenergy/gensetquiet.htmGreat bit of info there! The way i keep my Gennie quiet....I leave it at home and take my solar  |
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shinester
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China's white trash
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Post by shinester on Dec 31, 2013 1:19:15 GMT 10
Sound reduction is also about mass and insulation against vibration to stop the sound waves. Sand bags, brick walls, generator sitting on rubber will all help, as will digging a hole, putting sandbags over to top but not touching [boards then sandbags] and obviously having a way for air to come in and exhaust to get out. A small solid building [strawbale shed would be great] will do similar things and offer a much better permanent solution.
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ozspark
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Post by ozspark on Sept 2, 2014 20:28:04 GMT 10
I've heard of this type of thing before. The longer the exhaust path the quieter it gets. Just make sure you truly oversize anything long that you add to it otherwise the increased exhaust pressure will overheat the engine and reduce engine iutput power. To make it quieter again, put baffles along the additional length, eg in a 2" pipe put washers with a 1" hole every 2" or so over several feet or as per the video, just put a way too big off the shelf muffler on it.
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Post by You Must Enter A Name on Sept 2, 2014 21:30:01 GMT 10
I've heard of this type of thing before. The longer the exhaust path the quieter it gets. Just make sure you truly oversize anything long that you add to it otherwise the increased exhaust pressure will overheat the engine and reduce engine iutput power. To make it quieter again, put baffles along the additional length, eg in a 2" pipe put washers with a 1" hole every 2" or so over several feet or as per the video, just put a way too big off the shelf muffler on it. You make some good points but an exhaust system is a complex piece of engineering. Make the exhaust too large in diameter and the the exhaust pulses from the engine slow down, next you have pulses clashing into each other and a backlog builds up. Too large of an exhaust can be more restrictive then a smaller diameter exhaust. Baffles are good, the idea is to have somewhere for heat to escape too and dissipate. www.epi-eng.com/piston_engine_technology/exhaust_system_technology.htmNo offense intended, as I said, you make some really nice points mate. |
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overlord
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Post by overlord on Sept 3, 2014 11:33:53 GMT 10
As with any internal combustion engine, things like exhaust pulse and lower pressure areas are keys to creating a good exhaust system.
Balancing this off with noise can be a tricky proposition. Too big, you can end up wasting fuel, too small, becomes too restrictive for the engine to breathe hence not as efficient as it should be.
Single cylinder engines are a different ballgame compared to multi-cylinder engines (4, 6, 8) since you have a single cylinder to scavenge the same cylinder.
Based on experience, depending on the cc of the cylinder, for a small generator with maybe a 150cc engine, use a 0.5" pipe stepped to 0.75" after 3 feet. Introduce a chambered muffler of the same diameter Inlet and outlet after that, then another 0.75 pipe.
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kiwi
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Post by kiwi on Sept 4, 2014 18:45:28 GMT 10
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overlord
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Post by overlord on Sept 4, 2014 20:10:39 GMT 10
That is a good idea but I wouldn't risk having that tight a space for my generator. Note that even the author stated "In extreme hot weather John recommends that the generator be run for 30 minute durations only to avoid overheating of the generator"
I would build a small genset room for it instead.
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Post by You Must Enter A Name on Sept 4, 2014 22:44:14 GMT 10
Overlord you as always make some good points but regardless this is a very cool concept. Also I wonder if you run an exhaust system underground how much noise you can reduce, given that ground temperatures are fairly constant etc. |
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overlord
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Post by overlord on Sept 5, 2014 11:58:40 GMT 10
Overlord you as always make some good points but regardless this is a very cool concept. Also I wonder if you run an exhaust system underground how much noise you can reduce, given that ground temperatures are fairly constant etc. How about making a sandbox because the vibrations might (am making an assumption that the genset is not one of those suppressed vibration types) cause the exhaust pipes to break. The disadvantages of using soil as a compacting and sound deadening agent is that i absorbs moisture and may result in the rusting of the pipes also. |
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SM+?
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This old dragon will see you all when all this is over and done.
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Post by SM+? on Sept 30, 2014 23:37:10 GMT 10
I knew a guy how used a big old fridge with a hole in it and a thick long hose coming out of the hole, if you don't have a fridge I guess a freezer would work too.
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