Blue genny guy did the unthinkable!

road-runner wrote:

MEXICOWANDERER wrote: "The BEST portable generator sound suppressant is pyramid soft foam about four inches in depth. Making a collapsible four sided enclosure would chop emission 50% db wise. On big boats I built, extremely expensive suppressor motor mounts chopped noise level by an astonishing amount."

I don't think that's the right formula for the smaller generators. I experimented around with a big muffler on the exhaust, an enclosure, and concluded that the bulk of the noise comes from the cooling air exhaust. So I think a nice enclosure that lets the cooling air flow freely out won't help much. Baffles to muffle the cooling air might do the trick, making the enclosure bigger in the process. I have 2 comparisons to offer. With the eu2000i vs. quieter eu3000i, the 3000i's engine turns slower, has a better engine power to electrical power ratio, and has more overall mass. Another comparison is the eu2000i to the *really* quiet ex650. The ex650 produces one-third the power of the eu2000i with the same approximate overall size and weight, and its engine turns slower. We want a lot of power out of small, lightweight, and quiet generators. Each of those goals works against the others.

road-runner,

Right on with your comments above. The bulk of our built-in Onan generator's outside sound is the whooshing sound of it's cooling air exhausting out the bottom of it's cabinet. In fact it's sound level noticeably drops off whenever we park the motorhome on grass instead of asphalt or concrete. On hard surfaces the sound of it's cooling air flow reflects outwards more where it can be heard.

You're also correct about the Honda EX650 suitcase generator we carry in our RV. It is slightly heavier than an EU2000i ... but boy are it's 650 watts quiet. A great little genny for such things as coach battery charging, running a hair dryer on it's LOW setting, or in a pinch running a 2-way or 3-way RV absorption refrigerator on 120 volts AC!