Air conditioning

Looking into this atm as well. In our case, there is currently no shoreline power in the small harbor we will spend this summer and we also don't have/ don't want a genset. So thinking of a smaller split unit for camping like the Eurom AC3201E. Boat is a Cranchi Mediterranee 40 and we require this mainly for the nights. Not to transform the boat into a fridge but to ensure a workable temperature around, say, 25°C. For power supply, I will test my Jackery 1000 solar gen this year, although this will likely only suffice for 2-3 hours of cooling. However, using the timer function of the device this may suffice. Anyone else doing it this way? Wdyt of my concept? It's not ideal but can't think of a better way currently...
Also worth noting is that 21m3 isn’t a large space
 
Interesting unit but make sure you can attach it since your boat does not have windows like a camper but portholes .
Yes. Planning on placing the internal unit on the galley stairs and the external unit in front of the sliding entrance door. Again, not the perfect solution but the best I can think of currently.
 
Also note still it requires 240 VAC and relatively small cooling capacity so would take some time to lower the temperature of the cabin let alone remove any heat coming into the space on a sunny day

Mine are 12 ooo BTU each

I live 32 degrees south so in summer can be very hot and humid
 
With the incredibly hot weather of the past few week or so, I’ve been thinking about the possibility of fitting aircon on the boat.
Coincidentally I finally managed to get AC electrical schematics of the boat from the Jeanneau owners group - there were only drawings of the DC side on the printed manual I got and Jeanneau haven’t responded yet. This shows the Aircon option with one in the main cabin and one in the helm area. They work by exchanging to seawater rather than to air as per this.

It seems they have a dedicated shore line and/or bigger generator to run them.

On my boat the items with C prefix in this drawing don’t exist and the right side of the switch control panel (A55) isn’t populated.
So: Is it worth getting someone to quote to replicate this sort of system or am I better looking at ones that vent to air? I’d be fitting in both cabins rather than helm area.
What sort of size (BTU) are needed to cool the cabins on a smallish (11 metre) boat?
This would be a project for next year, to fit over winter, I’m off the boat for a month now and, when I get back I’m going to head further North, up to Bordeaux and thereabouts rather than back to the med which I will return to in late Sept/Oct.

I have a 10k BTU Velair unit in the aft cabin and it more than does the job. Half that would work OK, but you can't get really small units. Frigomar do good units too. If you have big windows or teak decks in the sun on your roof then it's altogether different. Power is tiny for my unit, maybe 250W when running, but on average a lot less, maybe 150W. Easy to do on batteries. Useful is to get a low power pump such as DC inverter controlled units so you can dial down flow to the minimum required. The usual for aircon installations is for installers to go crazy on flow. The pump uses ridiculous power in standard installations - can be 1kW for feed and chill pumps in a boat using only 1.5kW total power as they are sized for max demand in the tropics with huge headroom to deal with restricted pipes and a tired pump, not for night cooling in a well maintained boat. Look for these as non-marine spec.
 
These are A/C the statistics for a 20m Princess
5 separate units.

Main Saloon - 30,000 BTU
Main Cabin (main mid cabin) - 16,000 BTU
Forward Cabin - 10,000 BTU
Port Cabin and Crews - 12,000 BTU
Dinette Area - 16,000 BTU
 
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