3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
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I tried some sound abatement experiments yesterday with the ELM3000. I have posted some images and info at http://home.comcast.net/~rtagee/wsb/index.html. You can quick click here:ELM3000 Sound Abatement
Again, this link is the result of one of those cheesy quick and dirty home page generation programs for site creation within space given to me by my ISP. I don't have a lot of design leeway here, but it is fast and easy to generate!
As previously posted, the ELM3000 (or Powerwise 3500) muffler is extremely quite. So much so that there is little room for further sound abatement. The majority of sound is mechanical and comes from the shroud side of the engine. You will note in the photos I simply ended up placing a section of 3-1/2" fiberglass batting next to the shroud end of the engine and across about 1/2 of the gas tank. I also put a small piece on the back to close the gap at the corner where the air filter is. This method gave the best results. I did not include photos of my boxes lined with rubber carpet padding or the other enclosures I tried with no real improvement in sound reduction. Oh yea, the 69 dBbreading on the sound meter in the last frame came from the shroud side of the engine before any insulation was added. That photo is included just to show you the meter I used to make measurments - not the actual sound levels. I did manage to get an overall 3dB sound reduction (to 64dB) directly behind the generator at 20 feet distance. This 3dB is significant. The ambient sound level without the generator running that day was about 56 to 58 dB[A} with a light breeze.
I monitored engine temperature over a 30 minute period with a digital infrared non-contact themometer. There was no significant temperature rise with the insulation in place. Outside temperature was about 68 degrees F. Results may be different on a hot day and temperature needs to be monitored some more.
BTW, I cannot take credit for the exhaust stack idea. I saw this elsewhere for a fellow with a Honda 2000. Unfortunately, I do not remember where or who he was and as a result, cannot give proper credit. If someone knows where his photos can be found, I would like to give credit for a good idea to the originator.
I am extremely interested in what others may discover from their experiments on further sound reduction methods.
Again, this link is the result of one of those cheesy quick and dirty home page generation programs for site creation within space given to me by my ISP. I don't have a lot of design leeway here, but it is fast and easy to generate!
As previously posted, the ELM3000 (or Powerwise 3500) muffler is extremely quite. So much so that there is little room for further sound abatement. The majority of sound is mechanical and comes from the shroud side of the engine. You will note in the photos I simply ended up placing a section of 3-1/2" fiberglass batting next to the shroud end of the engine and across about 1/2 of the gas tank. I also put a small piece on the back to close the gap at the corner where the air filter is. This method gave the best results. I did not include photos of my boxes lined with rubber carpet padding or the other enclosures I tried with no real improvement in sound reduction. Oh yea, the 69 dBbreading on the sound meter in the last frame came from the shroud side of the engine before any insulation was added. That photo is included just to show you the meter I used to make measurments - not the actual sound levels. I did manage to get an overall 3dB sound reduction (to 64dB) directly behind the generator at 20 feet distance. This 3dB is significant. The ambient sound level without the generator running that day was about 56 to 58 dB[A} with a light breeze.
I monitored engine temperature over a 30 minute period with a digital infrared non-contact themometer. There was no significant temperature rise with the insulation in place. Outside temperature was about 68 degrees F. Results may be different on a hot day and temperature needs to be monitored some more.
BTW, I cannot take credit for the exhaust stack idea. I saw this elsewhere for a fellow with a Honda 2000. Unfortunately, I do not remember where or who he was and as a result, cannot give proper credit. If someone knows where his photos can be found, I would like to give credit for a good idea to the originator.
I am extremely interested in what others may discover from their experiments on further sound reduction methods.
