There are a number of threads on air conditioning in the Forum archieves under various subjects, but principally under Cabin and Interior. Here is a good one to begin with :
Air Conditioning.
For a rooftop A/C unit the Coleman Polar Cub seems to be a very good choice, as noted in the linked thread above.
Placing the generator unit is another issue, not only because of space issues, but more importantly because of the carbon monoixide danger. The very best solution seems to get it entirely out of the boat and down on the swimstep so the carbon monoxide is totally outside of the cockpit when exhausted.
You need also to get a very good carbon monoxide detector for your safety.
Dr. Bob (Thataway) has specific recommendations on how to do this, as he has installed a Polar Cub on the rooftop of his TC 255, placed the Honda 2000i inverter generator on the swimstep, and has evaluated various detection units, concluding that an aviation unit is desireable for it's sensitivity.
I can't answer all of the questions and details that will ensue, but this should get you started on the right track!
If you have time, take a look at Bob's rooftop installation of his A/C unit starting on page 1 of his album:
Thataway
Good Luck!
Joe. :teeth
