Thank you for the explanation Gary. I have a Honda 5HP on my
generator and I think I'll do some experimenting before I go and do
anything elaborate in terms of routing exhaust down a tube.

--George

On Sat, 11 Oct 2003 16:54:24 -0400, Gary Coffman
wrote:

On Sat, 11 Oct 2003 12:21:19 GMT, George wrote:
Why is it that the home generators are so loud? Is it that the
backpressure of a real muffler is too great? I've heard of people who
put better mufflers and even tubing to route the exhaust out of the
garage or where ever and they said they were happy.

An inadequate muffler is only part of the problem. The engine
itself radiates a lot of noise. This is due to design and materials
choices made for the cheap air cooled engines. So while adding
a good muffler will help, it won't make as much difference as
you might desire.

This is particularly true for gensets like those sold under the
Coleman name, where they cut every corner to get the price
down.

There are small engines designed with noise control in mind.
Onan, Kohler, Honda, Kawasaki, and Yamaha all have engine
series designed for low noise. Yamaha in particular has about
the quietest "contractor package" available. The difference
between it and a Coleman (Briggs powered) is dramatic.

If you look at the engines, you'll notice that the low noise ones
have added stiffeners cast into the block and head, and the
fan shroud is double walled with sound deadening material
between the walls.

Toro specs a "quiet package" from Briggs for their engines.
It has the double wall construction, but doesn't have the head
and block stiffening ribs. It is quieter than an ordinary Briggs,
but still much noiser than the engines which also have the
added stiffening.

Gary