Now that summer is here and I'm running all of the AC constantly, it was just last night that I told Ed, that I still have no regrets in having moved away from the split system and going to self-contained. I went with Aqua Air since they had some of the smallest footprints, the factory is local here in Miami, and I could buy directly from the factory. The footprint size was important to me because I was installing these in already-existing spaces where the old air handlers were. It took some modification in each location. Overall, the initial conversion was a ton of work to me, but I'm glad I did it.
With the exception of one unit that roars pretty loud only in the crew head (because the unit is sitting right above the ceiling in that spot), I can't say that these things are any louder than the old air handlers were. I sleep in that room where that head is, and by closing the door, it never bothered me and never woke me up. In fact, that one that roars in the head is incredibly quiet in the room it serves. Getting rid of the "all your eggs in one basket" situation has been a goal of mine since one hiccup in the old system wiped out all of the staterooms' AC, and if the hiccup were to be in the pump, then that took out the AC in the entire boat which, in Miami, means stop everything and go fix that right NOW.
I really like the fact that with self-contained, I can install it myself. You are correct that self contained is less expensive. In fact, the prices I was quoted made the self-contained cost less than half than the cost of replacing the split system's equipment, and with the split system, you then need an AC tech to come out and charge the system, unless you can do that yourself and if you do, don't bet that your warranty will be honored once you've tinkered with the system in the manufacturer's mind.
I went with giving each self-contained unit its own water pump - again, back to that removing that "all your eggs in one basket" thing. Now that the initial conversion is done, if I need to replace one, it really is "plug and play." The hard part is over. I was fortunate enough to have enough extra through hulls/seacocks from having removed the salt water heads and replacing them with freshwater Vacuflush, that I had ample access to seawater for each of the pumps. In your case, 30' is a long run of seawater. You'll need to assess your current pump's size and ability, together with how much head you have on that 30' run, and then determine whether it's do-able. For that long of a run, if it were me, I'd opt for give the unit its own pump and seawater access. If you have those seachests on the interior hullside, you can discharge the AC water there. I think every Hatt had those for discharging things like the sinks, showers, bilges, etc. You will also have to add a sub panel for the electric since each unit will require its own breaker. I used the original compressor's 40 amp breaker and ran that line to a subpanel with the appropriate sized breakers for each of the four self-contained units. I had a marine electrician come out and do that - that was the only hired part of this installation.
I look at AC down here where it's really hot as being somewhat of a disposable item. The cost to have someone come out and assess what's wrong and then fix it, can be almost as much as just buying a new unit. My stuff is new, so I do not yet have any experience to speak of in terms of what usually breaks on these. I did have one problem with my 16K unit - after about 20 hours, for some reason, the compressor seized. The factory replaced it and the only explanation I got was that it was a "rare compressor failure." I'm running the crap out of all of these AC units now, and it's nice and cool in here.
For the first time since I've owned the boat, the two forward staterooms - the ones that don't have any living space above them so they bake in the sun - satisfied their thermostats during the heat of the day. The original system could never do that here. For me, it's been a long-awaited and welcome change.
