dene wrote:
Again....don't hesitate to be critical and/or creative.

Seems like guilding the lily to me; the little Hondas are already
pretty quiet. On my boat, the deck vibration when the generator is
running is more of an irritation than the generator's sounds. Reduced
by putting the generator on a 1" thick piece of engine room sound
insulation. Or, put the thing on the end of the dock, almost
unnoticeable below decks.

Anyway, I'm highly critical. The instruction booklet is quite clear,
don't mess with the exhaust outlet, don't run in confined spaces.
Reasons? Exhaust back pressure and overheating. Your setup is
recycling a huge amount of cooling air through the generator and
roasting it good.

At the least, your "genny in an icebox" will have a short service life,
worst case a spectacular meltdown.