Generator Noise Level

[Lin]

I have always been somewhat sensitive about the possibility of my generator being noisy, and the disturbance is causes others.  I just downloaded an Android application that shows the readings of the ' different sensors  Since that includes one for sound, I tested my generator.  I got 40db at the loudest spot inside, 70db right next to the generator outside, and 60db a bit less than 20 feet away.  It seems that that would put it as similar to the little Hondas that have such a good reputation.

I guess the only way to make less noise is not to run it.

[TomC]

There is no such thing as a too quiet generator! Good Luck, TomC

[luvrbus]

DB is measured at 23 ft 60db is a normal voice you can get a generator down to 30-40 db without much work fwiw,Matt has one in his Eagle and it doesn't have a muffler lol

good luck

[Oonrahnjay]

DB is measured at 23 ft 60db is a normal voice you can get a generator down to 30-40 db without much work fwiw,Matt has one in his Eagle and it doesn't have a muffler lol           good luck 

     My gen is PDQ but I would like to have a removable "up to the top" pipe.  Anybody got a recommendation for rubberized (or similar) pipe that's good with the heat and exhause chemicals?

[Van]

Clifford ya mean there's a generator in there? I never heard one running  

[Mex-Busnut]

Lin:

What is the name of that Android app?

Thanks in advance!

[Lin]

Mex, the one I tried is called Androsensor.  The are many others that look to do the same thing.

Jay-- I have a rubber hose like the ones a shop would use to run a car's exhaust to the outside.  I slip one end on the exhaust pipe and hook the other to the lip at the roof line.  I don't find that it makes much difference for noise (though it did on the Onan on the last bus), but it sends the exhaust heavenward.  Watch out for asphyxiated angels!

[Oonrahnjay]

Jay-- I have a rubber hose like the ones a shop would use to run a car's exhaust to the outside.  (snip) 

     Yeah, just what I had in mind.   Don't know why I didn't think of it!

[Van]

Lin-according to this andrsensor app, my toilet is louder than my generator 

[Bill 340]

If you mean as a temporary up stack, I have seen several use a  aluminum down spout, elbows and all, works great,

[Sean]

...  I just downloaded an Android application that shows the readings of the ' different sensors  Since that includes one for sound, I tested my generator.  I got 40db at the loudest spot inside, 70db right next to the generator outside, and 60db a bit less than 20 feet away.  It seems that that would put it as similar to the little Hondas that have such a good reputation.

OK, before everyone runs out and downloads apps for their Android or iPhones, let's inject some reality here.  A real sound pressure meter will have very different results.

For starters, cell phones have very carefully designed microphones that are optimized for human voice at short range.  They respond only to a very narrow range of frequencies, deliberately rejecting sounds that fall outside that range -- a lot of the sound emanated by a generator falls outside of this range.  They are also highly directional, so they can't get a complete reading of all the sound pressure incident on a particular point.  Published figures are made with what is known as an integrating meter which accounts for this.

So you can't take a reading with a cell phone, no matter what app you use, and compare it to a published figure that is measured with a real sound pressure meter.  Even an inexpensive meter such as the one sold at Radio Shack will give you much more realistic results than an app on a cell phone.

DB is measured at 23 ft ...

Well, actually, dB can be measured at any distance, and there is a lot of confusion about just what a deciBel is, what it means in acoustic measurement, and how it is measured.  For one thing, a dB (deciBel, or one tenth of a Bel) is really a logarithmic measure of relative power.  So really the dB scale can only be used to measure the relative difference between two signals, not the absolute magnitude of a single signal.

That said, in acoustics, dB are normally measured relative to a reference standard, which is 0.000002 N/m² (considered the lower threshold of human hearing), and so it is common to see sound pressure expressed just a single number of dB.  In terms of hearing, just exactly how any sound compares also depends on the frequency of the sound, and for most noise-level measurements, we use what is called the A-weighted scale that adjusts for the frequencies according to the way we hear them.

The distance from the noise source is only one of the many factors to consider when measuring relative signal level.  I'm not sure where Clifford got 23' -- presumably that value is in someone's noise level standard someplace.  Honda happens to use 23' in their published specs, whereas Onan uses 10' in theirs.  For RV generators, many people use 50', simply because that's the distance that the National Park Service uses in defining the maximum generator (or other) noise.  (That standard, BTW, is 60 dBA at 50', which personally I consider to be unacceptably loud, but you can make that much noise in a National Park.)

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[luvrbus]

Got it from OSHA all construction equipment is measured at 23 ft even the portable light towers OSHA is PITA on that one they measure their 23 ft and take a reading then they tell you how long you can work a employee in that area with what gear

[bobofthenorth]

Here's a poor man's soundproofing technique - park next to me and nobody will notice your genset.  Love my aircooled Onan - at 800 feet you can hardly hear it. 

[buswarrior]

If you can hear the generator running, it is too loud.

SILENCE is your heavenly goal.

Yes, the rubber hoses for use in the auto shop do a nice job of dulling down exhaust noises.

Smart phone apps aren't necessarily for functionality, but for sure every time they are to make the app writer money.

Screw on your head, your smart phone is for making calls and surfing the net.

As for generator noise, you don't need an app, see line one of this post.

happy coaching!
buswarrior

[TomC]

The best generator I ever saw was one in a GMC 40ft buffalo.  I was looking it over when I felt some air on my leg.  It was the exhaust pipe with NO noise coming from it.  The only way I knew the genset was running was I put my ear on the bus and then heard a faint vibration of the genset running.  Now that's quiet!  Everyone should have a goal to make the genset as quiet as possible.  Good Luck, TomC