Aircon at Anchor

[RodeoClown]

Good morning All-

Once again...my caveat...new to this.

However, I have a 1991 Beneteau M38 for which I went through a major retrofit. I would need to get the details for you from my electrician, but my question for him was how to have air-conditioning while at anchor/mooring when our Florida evenings are still, humid, and have no-seeums and mosquitos (I blunted this by saying that I wanted my wife to be comfortable...).

His response: Generator.

My question: Can we do it with batteries instead? I don't want the noise of a generator nor the flammability issues with gasoline.

Answer: Yes, can run on a robust battery bank.

So, I/we replaced the forward/vberth water tank with 10 deep cycle lead-acid golf cart batteries. I also have wind and solar. Needed a new alternator for my Yanmar 3GM30F, smart relays, etc. This system is separate and isolated from 4 house and 1 starting battery bank. Anyway...after all was done, I can run 12,000BTU unit for 8 hours.

David

[Pete7]

David, I have moved your post to become a new thread because it is a separate question.

However, I suspect your electrician is correct a genny is the answer.

Pete

[belizesailor]

This has been discussed many times...search existing threads.

Youve already gotten the most realistic answer: generator (a diesel one if gas worries you).

[thinwater]

Generator. Just do the math on the amp-hours. You can get it to work for a few hours with a big inverter, but the batteries will take a licking. All evening and night, into the morning? No way.

[andreas.mehlin]

The youtubers, Gone with the Wynns, have aircon running from batteries and powered by solar....if I remember correctly

[Dockhead]

Spend some time at anchor first before you rush to spend a lot of money.

I cruised SW Florida (and points beyond) in all seasons for a couple of decades and never felt the need for aircon at anchor. We had air conditioning on board and desperately needed it in marinas, and used it there. But it's always cooler at anchor, and the boat will orient itself to catch the breeze. Put up wind scoops to improve air flow if necessary. Good screens everywhere will deal with the bugs.

It ruins the pleasure of silence and nature at anchor, to close yourself up in the boat and run the generator. Spoils it for others, too. Try wind scoops and I would be surprised if you don't see what I mean. Virtually no one cruising around Florida uses aircon at anchor other than giant motor yachts, and no one wants to be near them at anchor.

[Ltbarron]

Originally Posted by andreas.mehlin

The youtubers, Gone with the Wynns, have aircon running from batteries and powered by solar....if I remember correctly

That’s, correct. They just posted a video discussing exactly this. They use an “Easy Start” device in front of their inverter to dampen the high initial draw from the AC when turning it on. Apparently this initial high draw is what’s so damaging to the batteries. They have a large lithium ion battery bank.

[belizesailor]

Originally Posted by Dockhead

Spend some time at anchor first before you rush to spend a lot of money.

I cruised SW Florida (and points beyond) in all seasons for a couple of decades and never felt the need for aircon at anchor. We had air conditioning on board and desperately needed it in marinas, and used it there. But it's always cooler at anchor, and the boat will orient itself to catch the breeze. Put up wind scoops to improve air flow if necessary. Good screens everywhere will deal with the bugs.

It ruins the pleasure of silence and nature at anchor, to close yourself up in the boat and run the generator. Spoils it for others, too. Try wind scoops and I would be surprised if you don't see what I mean. Virtually no one cruising around Florida uses aircon at anchor other than giant motor yachts, and no one wants to be near them at anchor.

Installed AC when we lived aboard in a marina in Texas years ago...it was not a luxury, it was life support. But, have not used it since. I spin up the compressors once a year to make sure they still work, but expect they are dying a slow death. Have cruised all over FL and W Carib without using AC. Almost removed them this year to reduce weight and gain storage, probably will next season.

At anchor, good ventilation and sun awnings make a huge difference.

At anchor in the San Blas islands of Panamá now with wind scoops and sun awnings deployed. Quite comfy.

[belizesailor]

Staying cool tropical style, no noise, no fuel:

[belizesailor]

Originally Posted by RodeoClown

...

...Anyway...after all was done, I can run 12,000BTU unit for 8 hours.

David

12K BTU over 8 hours is a lot of juice...how to you plan to replace that?

[RodeoClown]

Yes it is

I have a wind generator, three solar panels, and, most importantly, a 160 amp alternator on the Yan Marr.

[belizesailor]

Originally Posted by RodeoClown

Yes it is

I have a wind generator, three solar panels, and, most importantly, a 160 amp alternator on the Yan Marr.

Have you done the math? How long put that much juice back in?

Have you actually ran a 12K BTU unit for 8 hours off your set up or is that calculated?

[Steadman Uhlich]

Originally Posted by belizesailor

Have you done the math? How long put that much juice back in?

Have you actually ran a 12K BTU unit for 8 hours off your set up or is that calculated?

Great question!

_________

And my questions are:

How much weight was put in the bow of the boat?
How much did 10 batteries weigh?
How does that compare to the weight of the water tank (assuming full) that was removed?

Have you slept on top of charging batteries before?
I have.
Be sure you (battery compartment, and sleeping quarters) have adequate fresh air ventilation.
I was on a boat with a big expensive new battery bank below a settee, woke up choking and had difficulty breathing when the batteries below me were cooking and off gassing while charging. Toxic fumes woke me up! If you smell "acid" beware!


______________

[smac999]

Originally Posted by RodeoClown

Answer: Yes, can run on a robust battery bank.

So, I/we replaced the forward/vberth water tank with 10 deep cycle lead-acid golf cart batteries. I also have wind and solar. Needed a new alternator for my Yanmar 3GM30F, smart relays, etc. This system is separate and isolated from 4 house and 1 starting battery bank. Anyway...after all was done, I can run 12,000BTU unit for 8 hours.

David

for one night. great. then you'll need a dock for 24h to charge it. you won't be charging that out in the water. system is fine for weekend warriors. if you want to spend a week or month out, you'll need a gen

[RodeoClown]

Is already a done deal. I’ve been using the system for over a year and it is great. Don’t need to worry about gasoline for the generator, the noise, or the hassle. Pretty quiet and all self-contained