Originally Posted by TripleEEE
My compartment door has no ventilation for the Onan 5500. Inside the compartment on the rear wall (exhaust side) there is expanded mesh for ventilation.
Ideally you'd want the exhaust kept separate from intake air for air-cooling at all times. If the exhaust is being spilled from the bottom of the generator and there are any path/s for it to travel back up and into the generator cooling fan intake then the generator will be drawing hot air back into the cooling air.
Having a seal of some sort that prevents this (such as a VW engine) is the way to go. Just be certain your cooling fan has a means of drawing outside air such as a vented compartment hatch.