Airconditioning for Beneteau Oceanis 50

[Bluewaters2812]

Can anyone share their knowledge regarding the installation of airconditioning into our boat? We have a 6kw Northern Lights with an 85hp Lister engine installed below the aft cockpit.

I would like to install 1 x 8000btu unit in the saloon with a 2-way valve to service the aircon into the saloon and with it switched the other way, for it to service the foreward master cabin. The 2nd 8000btu unit will install in the 2nd aft cabin and also have a 2 way valve that will enable aircon to be fed to either one or the other aft cabin (its the owners 3 cabin version).

Has anyone got any experience of this, essentially I want to know whether the generator will handle the 2 x 8000btu systems. I am guessing it will as long as each one is switched on separately and not all at once?

[s/v Moondancer]

We have a 55 ft boat and the A/C has to run all the time for 16,000 btu to cool the boat. It takes two 16,000 btu units to cool the boat at the end of a hot day's sailing and they struggle when we are cooking.

However, 8,000 might get one bedroom cool.

[Sailmonkey]

a 6kw Northern lights won't even hickup when running two 8K units.

I am more curious how you plan on valving them, and why?

[Bluewaters2812]

Originally Posted by s/v Moondancer

We have a 55 ft boat and the A/C has to run all the time for 16,000 btu to cool the boat. It takes two 16,000 btu units to cool the boat at the end of a hot day's sailing and they struggle when we are cooking.

However, 8,000 might get one bedroom cool.

Thanks Phil. The thought is to use the one unit to cool the master cabin and the other one to cool one of the aft cabins. Its generally just the Admiral and I that will be on board so changing the 85hp engine is not prudent. It only has 400 hours on it.

I can imagine that it wouldn't be very effective in the saloon if one is cooking. The way I envisage setting it up is that each unit will only service one room at a time. Its a slightly cheaper way than having both units try and service all rooms at the same time, which I doubt would work.

[Bluewaters2812]

Originally Posted by Sailmonkey

a 6kw Northern lights won't even hickup when running two 8K units.

I am more curious how you plan on valving them, and why?

That's good to hear. Well, I thought that it wouldn't be strong enough to run both 8000btu units at the same time, so maybe I can simply pipe the aircon to all 3 cabins and the saloon? 1 unit to the master cabin and saloon and the other to the two aft cabins? I really no nothing about aircon units so am open to advice thanks.

[Sailmonkey]

Originally Posted by Bluewaters2812

That's good to hear. Well, I thought that it wouldn't be strong enough to run both 8000btu units at the same time, so maybe I can simply pipe the aircon to all 3 cabins and the saloon? 1 unit to the master cabin and saloon and the other to the two aft cabins? I really no nothing about aircon units so am open to advice thanks.

In what climate are you planning using your boat? For the tropics, or even areas like the US gulf coast you're way undersized for daytime comfort. You might be able to cool off at night.
Your generator will easily run two 16K btu units, and then you can cool the whole boat during most days.
This really all depends on what you hope to accomplish and where you want to accomplish it.

[Bluewaters2812]

Originally Posted by Sailmonkey

In what climate are you planning using your boat? For the tropics, or even areas like the US gulf coast you're way undersized for daytime comfort. You might be able to cool off at night.
Your generator will easily run two 16K btu units, and then you can cool the whole boat during most days.
This really all depends on what you hope to accomplish and where you want to accomplish it.

Thanks for that. Well the only reason I spoke of two 8000btu units is because the surveyor reckoned the 6kw would not handle two 16000btu's, so now I am well puzzled lol?

[Sailmonkey]

A 6000 Watt generator is capable of producing roughly 50 amps at 120VAC.

A typical 16000 btu AC unit will draw 10-12 amps running. Starting may be up to 30 amps, but not likely. There are soft start kits to alleviate these concerns too.

So you can run two and have a little power left over, but I wouldn't run the water heater using the electric element, rather use the hot water from the engine.

[Bluewaters2812]

Originally Posted by Sailmonkey

A 6000 Watt generator is capable of producing roughly 50 amps at 120VAC.

A typical 16000 btu AC unit will draw 10-12 amps running. Starting may be up to 30 amps, but not likely. There are soft start kits to alleviate these concerns too.

So you can run two and have a little power left over, but I wouldn't run the water heater using the electric element, rather use the hot water from the engine.

Thanks, that sounds like sensible advice and makes sense to me. Obviously if both units start up together they will possibly kill the generator, so is the answer to have them start separately?

[Davelrb75]

For a boat this size you might want to consider a multizone split system with one compressor located in the engine space or a lazarette and then however many zones of air handlers and condensers you need. That will save space on bulky duct runs and cut down length of seawater runs etc.

They do also make controllers that will ensure only one unit starts at a time. Very straightforward.

[Bluewaters2812]

Originally Posted by Davelrb75

For a boat this size you might want to consider a multizone split system with one compressor located in the engine space or a lazarette and then however many zones of air handlers and condensers you need. That will save space on bulky duct runs and cut down length of seawater runs etc.

They do also make controllers that will ensure only one unit starts at a time. Very straightforward.

Thanks, I will have to look into it more carefully by the look of it. Probably do it in Saint Martin but not sure.

[67Therapy]

I've no issues with 6KW NL genset running both 18K and 10K air conditioners.

[Bluewaters2812]

Originally Posted by 67Therapy

I've no issues with 6KW NL genset running both 18K and 10K air conditioners.

Once again that is just the sort of response I need, thanks for the input.

[muskoka]

I ran 2 x 12,000 BTU's from my Northern Lights 6kW genset. I started the AC's separately but there seemed to be no problem running them both.

One of them is ducted so that it can do just the salon or divert about 30% of the airflow to the guest cabin. I made the diverter box out of starboard and insulated it. The flap is activated by a Bowden cable (like a bicycle cable).

Except at mid-day in summer, I find the one unit sufficient to keep the boat comfortable - but then I don't like icebox levels of aircon and we live in shorts and T-shirts.

Cheers

[bobconnie]

We are running a 12000 and a 16000 with a 6.5 gen set on a 51 ft boat. no problems of any kind! The 12000 cools the aft master and the pilot house, and the 16000 the galley, saloon, and the forward if needed. I can't see ya haveing any problems, except maybe the ducting and that such of thing ! Just my 2 cents. And we live in south Louisiana and have high heat and humidity.