Plus, does it pay off to work so hard to make an exhaust piping system
for something that may not be likely to live long.

I changed my exhaust to a 3/4" copper ell and tubing 8" in length.
Slotted the end of the ell and used a SS hose clamp it to the steel
exhaust.
Just friction tween the ell and the tube.

The other end goes through a 3/4" hole in a little 1/8" thick rectangle
of sheet of asbestos board (from a kiln) attached to a 6" high x 36"
wide sheet of plywood that seals the single hung window.

I ran it for 30 minutes today and I could not detect any leaks or
shifting.

Not a lot of work.


BTW The generator ran for 30 minutes and nobody in my house even
noticed it running.