Airflow management is pretty simple on these: Lots of air goes in the fan on the front and is mostly ejected out the cooling louvers above the batteries. There's also a small air intake quantity into the air filter and the control box end of the generator, and a warm air exhaust at the flywheel end of the generator.
The noise comes from the cooling fins ringing with diesel knock and the cooling air flow, particularly the blower noise. Exhaust noise is noticeable, but a small muffler and directing the outlet up (like a tractor) solves that problem entirely.
If you look at the ASK, there's a louvered noise dampener around the cooling fan intake, a hot air exhaust directing the cooling air up and over the exhaust piping, and various closeable access ports to enable starting and servicing the generator. Fairly good diagrams can be seen in the -24P manual.
