We have a 1996 era KingAir 16,000 BTU A/C unit aboard our 1986 Beneteau First 42. The unit is mounted amidships, in the main salon, under a seatee return. We do not have ducting. The exhaust fan blows cool air through a wedge shaped vent near deck level and fans blow the cooled air into the fore- and port quarter cabins. For our boat, in the Tampa Bay area, 16,000 Btu's makes the boat as "cold as a meat locker", even in the Summer, according to my [much] better half. Our raw water intake is a dedicated through-hull below the sink in the galley that feeds a 500 +/- gph air-cooled March pump through a Groco raw water strainer with the discharge in the transome about a foot above the waterline. We also have a Mermaid "Condensator" to extract and discharge condensate into the raw-water discharge line but it works only intermittently and I would not make an investment in one again.
On your yacht I suspect that a 9,000-10,000 BTU unit would be quite adaquate. We dispensed with the duct-work as we have more important things to store in the backs of our lockers and I suspect you may as well.
PS: Our unit is a reverse cycle system and in winter here in Florida, it WILL drive you out of the yacht, even in 30 deg. weather. While I dislike the people at KingAir somewhat, the equipment is first rate if you're trying to decide on the equipment.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
Last edited by svHyLyte; 07-10-2009 at 08:36 PM.
Reason: Add PS! & Correct typo!