CPseudonym wrote:
Reinforcing the cabin top, whether wood or fiberglass will be a given. The question I would be asking the rep would be the recommended size of the reinforcement to provide a stable platform to isolate the vibration. There are many commercially available, as well as industry standard self constructed ways to mount the outside unit. Concrete pads are great where practical. I have used purchased fabricated roof curbs and old school redwood sleepers that the roofer would mop in. Neither look very 'yachtie' for lack of a better term. I don't understand the aversion some have to running a generator while AC is in use, Sport fish boats in the 45+ foot range are designed to have the generator running almost the whole time they are away from the dock from the way I have had it explained to me. I am a newbie so I could be mistaken.
Vibration isolators come in many configurations depending upon level of dampening desired.
What kind of reinforcement is currently in place for that dual-pack sitting on your roof? If it's sufficient for that monster, I would assume a light weight mini split or two should mount on the same location fine.
I agree with the advice against PVC duct work in a marine environment. Any duct work should be heavily insulated IMO.
BTW Swampu, I love that boat!!! If you have a blog or an on-line repository of the photo history of the work you've done I for one would love to see it.