Van mounted Gx390 cooling question

I have a transit connect with shelving on both sides and I have mounted my gx390 pressure washer. It is a small van so I recently reorganized it to make more space and moved Is there a certain amount of space the motor needs around it to cool? Would I be able to run a 12 volt fan for cooling off the pressure washer’s battery? I plan to leave the back and one side door open while running the engine.

For what it’s worth I run a GX630 V-twin in a 5x10 enclosed trailer. As long as the doors are all open it should be fine, but the exhaust needs to be pointed out a door somehow.

You go to close all the doors and drive off with all that carbon monoxide, it won’t be pretty, not to mention a potential for fire.