A/c on Jeanneau SO 43 DS

[Donrob]

I am planning to install air conditioning on my Jeanneau SO 43 DS in the saloon. I sail mostly in the Southern Mediterranean and I have been advised to install an 18,000 BTU unit with two blowers and two air delivery outlets, a high one on the main bulkhead (whose ducting will also be used to throw cool air into the forecabin) and the other behind the dinette seating close to and pointing at the galley area. The a/c unit will be placed under the dinette seating against the main bulkhead which i understand is where the factory would have installed it. Can anyone on the forum inform me of any pitfalls to avoid in such an installation? Are there better ways of doing it? Could the unit be too strong/noisy? Any ideas of how to keep the noise down? The a/c will be used mostly during day time/evening not the night.

[Seagem]

My SO42i has previously been fitted with an AC unit in port lazerette but it only fed cool air through a grill cut into the rear cabin bulkhead. The previous owner just left the rear cabin door open to circulate air into the saloon. Not the best system! but not a bad place for the AC unit if you can find a way to route the outlet ducting. There are two through hull fittings, an inlet next to the engine cooling water inlet and an outlet above water line out of the rear lazerette.

[Zanshin]

I had AC on my 43DS and it worked wonderfully well in the hot humid Caribbean summer while at dock - but it was rather loud, almost to the extent that speaking in the dinette area in normal tones wasn't possible. I wouldn't downsize the BTUs but would think about doing some soundproofing but most of the noise came from the cold air itself, not the blower unit.

[Donrob]

Thank you both for your comments. Regarding the noise I suppose to an extent this is inevitable because of the design of boat air conditioners which have a small air outlet compared to the domestic ones.

[rxc]

My 43DS has two A/C units. One is under the dinette seat you mention, while the other is in the bilge right under the spot where the cook stands when using the stove. They removed the storage shelving there to make room for it.

I think that the forward unit is 15K BTU, while the aft one is 8K, and both of them are Webasto reverse cycle units that provide heat as well as cold. The forward one blows into the main cabin right at the stb chainplate, and into the fwd cabin on the other side of the bulkhead. The aft unit only deals with the aft cabin. I have a 2-cabin boat.

Location of the vents in very important. A friend of ours with a 3-cabin 43DS had problems with the vent into the fwd cabin that blew directly on the head of the crew member in one of the small berths. Ours is not so sensitive, but the relative location of the thermostat and the vent can be tricky. The aft unit vent comes out of the bulkhead aft of the stove, close to the deck.

Blower noise is the biggest issue, and our large Webasto is pretty loud at full speed, but the fan speed can be adjusted to make it liveable, and even sleepable. However, if you have to use the genset to run the A/C, then it will be noisy. With just us on board, we frequently use only the fwd unit for heat while we sleep aft. For cooling we will use the aft unit only, and it is quiet enough to let us sleep well.

We are generally happy with them. We use the heat more than the cooling, and I would suggest having two smaller units rather than one big one, for reliability and to better control electrical loading. Ours are now 6 years old, and we haven't had to have anything fixed, yet.

[Donrob]

Many thks for compressive answer. I was planing to use space between aft cabin and transom for aft a/c unit but your option of locating under sole in front of stove sounds like an interesting alternative.