Looking for 10k-12k BTU.
If they don't hang outside the window they'd have to hang inside the window, and would need a more complicated ventilation system to take air from outside, heat it up and vent it back outside. At that point you'd have a window mounted two hose AC anyway.
So yes, your next best option is going to be a two hose portable AC. One hose takes air from the outside to cool the condenser, one hose to throw that hot air outside.
Single hose works too, but they're less efficient because they take cold inside air, cool the condenser and vents it outside, which waste some of the air it just cooled for that and it creates negative air pressure inside which will bring hot air from the outside to replace it from any cracks and holes in the house.
I understand! So then given my limitation, a dual hose portable AC unit is my best option.
No question. We used a single hose one for years and it was way better than the window units in almost every sense (except for the above mentioned efficiency issue). Setup is simple, you can move/point it to a more desirable location, breakdown at the end of summer was simple, and ours was remote controlled (though this seems more common on window units too these days).
Get one that is a heat pump and not just AC for more efficiency.
