Awesome story, loved the pictures of building out the van. One concern I have is that if you are idling the engine and have the fantastic fan on, wouldn't you

Awesome story, loved the pictures of building out the van. One concern I have is that if you are idling the engine and have the fantastic fan on, wouldn't you be sucking exhaust fumes into the vehicle? Or is the hole at the back meant for exhaust with the fan pushing air in?