A/C in Lagoon 450

[Luckyme]

HI,

I just bought a Lagoon 450 2011 and I want to add A/C in it. Papillon is based in Nassau Bahamas and I want to use her during summer time. To do so I need to add A/C in it. Do I really need all A/C as suggested by Lagoon, 4 x 8000 BTU (8KBTU per room) + 1 in Galley 16000 BTU with a generator 13KW. It sounds way too much for me. I want a comfortable boat and I don't want over kill her with all of those equipment. Is 16000 BTU with 6 KW would be sufficient to be comfortable?

Thanks so much for your input.

[a64pilot]

I have a 38' mono, and it takes every bit of a 16k and a 5k.
Would have been better if the 5k was an 8k, but I wanted the small one.
I'd guess you might could get away with 3 16K's? One in each hull and one in the Salon
Same BTU's, just less units.
Real problem is when you get to the boat in the afternoon and want to cool everything down, that takes a whole lot more cooling than you think.

[scuba0_1]

I would think they know what makes there boat most comfortable. It would suck to spend all that money and not get it right. I know if it's not enough they will run and you will be replacing them.

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[yeloya]

We installed many AC and gensets. For L 450 and Helias, 8.000 btu per cabin is OK Even 6-7.000 Btu also is OK, it would just take a bit longer to cool down yr cabins. Installing the AC to the saloon is senseless in my view.. Why one should sit inside under AC on a boat ?? Stay at home then ..
At worst, if you really need stay inside in a vey hot night, you can start the A7C in all of the cabins , open the doors, you should be OK in the saloon. In that case 6 KW genset is the minimum. (we usually install 8 KW to have some spare energy, there is very little price difference between 6 and 8 KW anyway.)

If you want in the saloon as well, then, you will need an extra 18.000 Btu as this area is more exposed to the sun + more windows... 16.000 suggested by Lagoon is the minimum.
So if you want 4 cabins + the saloon 10-11 KW would be required.

When deciding on the genset, as you are sailing on a catamaran have a close look at the weight and the space they are taking. I recommend Fisher Panda's which are the lightest and more compact.
You should always add to the theoritical calculations at least 35-40 % safety margin. More, if you have a 220 V water maker, electrical winches, coffee machine and a wife with a hair drier on his hands all the time

Cheers

yeloya

[Luckyme]

Thanks for your input, have you ever install in a Lagoon 450 one 16,000 BTU for front rooms and one 16,000 BTU for back rooms? that way you limit # of through Hull and equipment. I would find noisy having a A/C under my bed.

[DotDun]

I have (2) 16k reverse cycle units. Mid-day in the summer when it's 90 outside with 80+% humidity, they would have to run constantly to get the inside down to 80-82 and <50% humidity (which actually feels cold). I don't do this very often as when it's nice outside, that's where we are (I rarely get over heated when on the water wearing a swimsuit and t-shirt, if so, that's what the water is for!). When on the boat, I use the system more for heat on cold mornings than cool air in the summer. When not on the boat, they are set for de-humidification.

It sounds like Lagoon is suggesting a system that will get the boat to 72-75 degrees inside when it's 90+ outside. That's OK if that is what you want.

A friend with a Leopard 39 installed a 10k unit for the whole boat and it's great to remove the humidity for night time sleeping, but can't even begin to keep up with mid-day temp/solar heat, but that wasn't the goal.

It all depends on what you're trying to accomplish.

Marina queens with unlimited shorepower and desire 72 degrees take lots of BTUs.

[TOT]

Hi Luckme
We have a Lagoon 450 and live in Singapore and l can assure you that once you hit hot climates such as SE Asia you will need ever little bit of air conditioning you can get your hands on, we installed them at build via Lagoon and have a 11 kW generator and use it frequently due to the 34 degree heat and 90% humidity.

Don't skimp you never know when you need what you need....

😃

TOT

[Sailingcouple13]

Lagoons recommendation is based on having independent climate control in each cabin. Best for charter to keep all guests happy. Nothing wrong with using one larger one for multiple cabins, just keep in mind return air, a cabin without return will not cool properly with door closed. We use two 16000 btu on our 45 voyage one in each hull and in 90+ Florida heat it is a big improvement over the 12000 btu we replaced. We have a very large bridge deck which we only AC at night if we have a bug problem or midsummer rainy day. This is done with same two ac units ducted to the bridge deck closing vents below with cabin doors open for return. Works great! In reality the only time we really use the AC is for sleeping, or at a marina then it stays on always in the cabins but rarely on the bridge deck. As far a noise from ac in cabin, it is a lovely thing to hear blocks out all marina noise

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[HappyMdRSailor]

DANG@!

Where's everybody's manners!?!?

Welcome to CF Luckyme !

As everybody says... If you truly want to make it a different climate, you'll need every single BTU you can stuff in the boat... BUT... It's lotsa $$$, weight, and spendy to keep cool...

16k total will take the edge off, but that's it... Two 16's won't make you think of an AC cooled building... Best to start getting used to sailing comforts and compromises...

Originally Posted by a64pilot

I have a 38' mono, and it takes every bit of a 16k and a 5k.
Would have been better if the 5k was an 8k, but I wanted the small one.
I'd guess you might could get away with 3 16K's? One in each hull and one in the Salon
Same BTU's, just less units.
Real problem is when you get to the boat in the afternoon and want to cool everything down, that takes a whole lot more cooling than you think.

SPRAY THE BOAT DOWN FIRST!

[rwidman]

Originally Posted by scuba0_1

I would think they know what makes there boat most comfortable. It would suck to spend all that money and not get it right. I know if it's not enough they will run and you will be replacing them.

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Yep. If the boat's manufacturer recommends something, I don't think you'll get better advice from strangers on the Internet. If you don't trust the advice from the boat's manufacturer, get the advice of a couple different experience marine AC installers.

Spending several thousand dollars only to find that it doesn't do the job and has to be ripped out and several thousand more spent would be disappointing at best.

[jmschmidt]

7.5kw gen for a Leopard 47 we owned was more than enough. Don't remember the BTU of the a/c units but you can look it up.

[JayH]

My 48' cat has a 5k in each of the four cabins and a 16k in the salon.

The 5ks are enough to keep the hulls cool, but they would be useless to cool the salon. My salon needs more than the 16k, but that's all that would fit. It does okay with shade awnings and window covers up, but otherwise has a hard time keeping up.

A 9kW generator powers them all just fine.

[Luckyme]

Originally Posted by JayH

My 48' cat has a 5k in each of the four cabins and a 16k in the salon.

The 5ks are enough to keep the hulls cool, but they would be useless to cool the salon. My salon needs more than the 16k, but that's all that would fit. It does okay with shade awnings and window covers up, but otherwise has a hard time keeping up.

A 9kW generator powers them all just fine.

Hi JayH,

Thanks for your reply,

Do you have extra power with 9KW generator to also charge your batteries? Which brand of A/C and generator
have you input in your boat?


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[JayH]

My A/C units are Webasto FCF 230V.

My genset is from Beta Marine. The generator end is a Marathon Pancake, which I think is the same as a Northern Lights (1800 RPM, brushless, synchronous, externally regulated).

Doing the math, the A/C units take about 49% of the generator capacity, and the battery chargers take about 72% at max charge current. So I can't run it all at one time on the generator. However, I wouldn't do that anyway.

I can do three things to manage the load on the generator.

1) I can choose which air units to run. Typically we're not using the salon and the cabins at the same time.
2) I can wait for the charge current to decline before turning on more units.
3) I typically run the air conditioning through the inverter/chargers when away from the dock. The inverters can manage the current drawn from the generator to prevent overloading it. This way I can turn on whatever air units I want, and the chargers will just use whatever capacity is left. Going through inverters also allows me to run limited aircon from the alternators or a Honda.

[Luckyme]

Hi JayH,

Do you have 2 power shore cord or only one?