I have looked into AC for my SF44, but have so far not installed any. The problem is space, both for the
gen set and the AC itself. I currently run dual Honda 2KW gensets that I set on the aft swim platform.
This works well for AC power, as long as there are no rain showers in the vicinity. I use this for a huge
fresh water maker (about 1 gallon / minute) I installed in the port hull, forward of the tub.
There are cabin-top AC units you could run, cold air dumping into the main cabin, but you would need a
storage location while underway. I have made some cut passages that would have dumped them over
the side. Then you also need to figure out how to get power to them.
Diesel engines do not take kindly to being lightly loaded, so I am thinking you would want an aux genset.
These exist, and the most likely installation area would be under the table beside the helm or the rear
lazarette. Then you have the problem of diesel fuel feed and exhaust. (I assume a diesel genset, I would
not install a gasoline unit on my boat, though my Honda gensets are gasoline fed.)
My most rad idea was to buy a cheap "Hier" (Chinese) AC from home depot (maybe $200 to $300). Take
it apart, cutting the refrigerant lines and all. Then take the pieces and install them behind the curve in the
main cabin seating (there is a fair amount of room there). Then ducting the cold air into the cabin, possibly
under the raised flooring for the table, possibly into the starboard sleeping cabin. I haven't figured out
what to do with the exhaust hot air yet. I hate cutting holes in my boat.
One thought that occurs, you could run the heat exchanger lines forward to the locker at the foot of the
mast. You would have to open that locker to let the system exhaust heat every time you wanted cold air,
but it could work for you. I would not leave the heat exchanger exposed to salt water or spray. They would
eat the exchanger alive in one season.
Anyway, re-assemble all AC connections, charge the system with refrigerant, and away you go. I doubt the
entire installation would run more than $500.
Now you have to feed power to the system. I currently have on my boat a battery bank of Chinese AGM
batteries of > 1KW. This might do it, but it could be close. AC is very power hungry.
The alternative is to run your Honda gensets all night, unlikely to make you many friends in crowded
anchorages. All gensets are noisy, some more than others.
These are my thoughts. Sometimes the importance of AC fades. Then, one night in a still anchorage
being eaten alive by no-see-ums revives my interest considerably.
The problems you will face are:
1. where to put it.
2. how to power to it.
Let me know what you decide,
PS: You may find that your asthma problems are significantly reduced while cruising, depending on where
you go. Generally, the wind is out of the east, and has been scrubbed by 2K miles or so of ocean.
PPS: You can get a SF 50 with AC, if you can swing the price. The 44 is sexy, the 50 is elegant, and no, I
can't swing the price myself, but I love my 44, AC or not.