There are kits on eBay to extend your exhaust. Just search on eu2000i exhaust extension. The problem with the small generator
in an enclosed space such as a lazarette isn't so much heat it's gas fumes. The eu2000i doesn't have a closed loop fuel
system and as such fumes could accumulate in the bottom of the space. Without adequate forced air exchange you could have a bomb in there.
Exhaust pipes for these small generators can be wrapped and there are proper thru hull
exhaust tips (search on webasto exhaust tip).
Just some thoughts to consider. Good luck.