We researched this after our 2009 rooftop Coleman 13k unit died and went to Coleman heaven prior to getting a Coleman 15K unit installed.
The largest BTU unit we could find that would fit in the front opening of our TC255 window was a 6000BTU LG LW6017R from Home Depot. Your local Kitty Hawk store has one for $242. It has a nice remote control. It’s quiet and works well. The surrounding ‘insulation’ is a weak point.
https://www.homedepot.com/p/LG-Electron ... 136?NCNI-5
You will need to ‘’insulate’ around it with pool noodles etc, which also must be ‘stored’ when not in use.
The Honda 2000iu is a great PORTABLE generator, (we have two) but it is NOT designed or engineered to be safely used as a 120v power source for boats. Especially when it (with a floating ground) is plugged into your boats shorepower inlet (no floating ground).
Instead plug the window AC directly into the Honda to cool down the interior before going to bed. Then shut down the Honda before going to sleep, regardless of ‘exhaust direction’ wind etc.
We are NEVER comfortable with the idea of going to sleep with ANY internal combustion engine of any type running on our boat, even with multiple marine rated CO detectors. Try multiple ‘Fan tastic’ 12v RV fans to stay safely cool and safe til morning.
https://www.amazon.com/Fan-Tastic-Vent- ... 8108&psc=1
Safely re-fueling the Honda on the boat is yet another danger.
There are 31 flavors to cruising, and your crew must decide what flavors are right for you and yours.
Any RV rooftop AC unit needs only a 14x14” hole in the roof and three AC wires to your AC panel to have easy, safe, instant, hassle-free air conditioning on shorepower at any marina you choose. No hassles storing a window AC and and a generator and a safe way to re-fuel the generator.
Hope this is helpful.
Choose your flavors and be Happy!
Safe travels!
John