A/C and electrical Upgrade

[LivingWhale]

Originally Posted by CaptainRivet

Genset:
It’s not only the setup costs, if you choose a genset it’s the maintenance, the Noise while using and the costs for fuel that’s add up. And gens are prone to break and frequently need fixing too.
Solar is basically maintenance free besides keeping the panels reasonably clean, quiet and properly installed work without hassles. There is never too less solar, stick on what you can fit…the best bifacial panels you can find and afford, every penny spend here pays off. 24V system is a must and Victron MPPT solar chargers.
Your 2nd best choice are big alternators on your engine…big because they put significant power in during the 30min of going into an anchorage till you switch it off after anchor properly set. So you don‘t need to run them additionally or if then just a short periode of time on anchor to recharge.

This is definitely the way I would like to go. I was told by someone (can't recall who) that you can not use the engines with large alternators in substitution for a generator.

I have room for 4 large solar panels on top but I could do 3 or 4 off the back as well. In either scenario I think I could yield about 1600 watts or with both over 3000. I like the idea of lithium for many reasons and would try to do 1200amps if there's enough space. One challenge is they are under the main berth so they will produce heat when charging . There's no air conditioning on the boat. The main cabin is the primary place; however, it would also be nice to have the other cabins to cool if we have quests (3 cabins total). Also would be nice to cool the salon too. With proper ducting I feel like I could manage the salon or the two other cabins by redirecting the air flow. So lets talk cost here - Lithium and controllers and additional inverter 16K? Solar $10K but could be more depending on the structure, etc. 3 A/C units 12v top of the line $25K. Upgraded alternators (guessing here) - $4K. So $55K total. How far am I off here?

Or if I went with a generator $20K, plus A/C $20K = $40K and that's not additional solar or lithium.

The first option seems like the better deal as long as it works and I haven't miscalculated. But I also have to find someone who can help me install all of this that isn't too far away. Being in South Carolina I have until April to solve for this before it starts getting very hot.

[Pizzazz]

Lithium is great to have on the boat but not for heating/cooling. You will spend a lot of money and end up disappointed (as in, when you need AC the most, you will not have the juice to run it).

Install a diesel generator. They are not that noisy, produce a pleasant rhythmic sound and are way more efficient than large alternators on the engines. The AC itself is quite noisy with the water pump and the handlers. The cabin will be closed when you are cooling it down, so you will barely hear the generator. You will have efficient cooling, heating even cooking when you need it.

[Adelie]

If you want AC off or solar/batteries you need the smallest possible unit.

1500BTU doghouse AC unit, draws about 300W. With this you can cool one small cabin for 8hr provided you insulate the walls and overhead. Assuming it runs constantly that’s 2400Whr, which at 12v is 200Ahr.

Storage: Since you don’t want to completely drain a battery, even LiFePo, you want about 240-250Ahr dedicated just to the AC.

Energy Production:
Using MPPT controllers rule of thumb is 1/3 of nameplate capacity equals average daily production in Ahr. You need at least 200Ahr divided by 1/3 equals at least 600W of panels dedicated to AC needs.

[LivingWhale]

Originally Posted by Adelie

If you want AC off or solar/batteries you need the smallest possible unit.

1500BTU doghouse AC unit, draws about 300W. With this you can cool one small cabin for 8hr provided you insulate the walls and overhead. Assuming it runs constantly that’s 2400Whr, which at 12v is 200Ahr.

Storage: Since you don’t want to completely drain a battery, even LiFePo, you want about 240-250Ahr dedicated just to the AC.

Energy Production:
Using MPPT controllers rule of thumb is 1/3 of nameplate capacity equals average daily production in Ahr. You need at least 200Ahr divided by 1/3 equals at least 600W of panels dedicated to AC needs.

That is helpful and sounds doable. I don't need it to be 68, but a little cooler and less humid makes a big difference.

[FlyingScot]

I tried a 1500 btu/hr unit and it wasn't nearly enough to just do our bed area in our 40' catamaran. It would drop the humidity by 10 percent, but the temperature barely went down. We tried to get creative, but in the end it wasn't enough.

[flee27]

Don't know about real world. but from specs you should be able to run the Velair 10K BTU variable speed unit in eco mode (3000BTU) for less than about 250 AH @12 volts including the water pump.

This should do an acceptable job of keeping a sleeping cabin comfortable from my research. Again this is not real world experience. But would love to have someone's real experience with these units because as has been discussed, numbers like this are doable via batteries.

Foster

[LivingWhale]

Originally Posted by flee27

Don't know about real world. but from specs you should be able to run the Velair 10K BTU variable speed unit in eco mode (3000BTU) for less than about 250 AH @12 volts including the water pump.

This should do an acceptable job of keeping a sleeping cabin comfortable from my research. Again this is not real world experience. But would love to have someone's real experience with these units because as has been discussed, numbers like this are doable via batteries.

Foster

Exactly! Hoping real word experience chimes in .

[SV Confianza]

Quick note to the balmar xt170 crew on this thread. Had 1 of them fail already after only 6 months. Using the wakespeed balmar profile (temp regulation) with extra safety for fault if no temp sensor detected. Will see what balmar says.

[cdreid]

Originally Posted by Peeew

I did talk to an electrical company doing a big project on a new boat to be able to run 3 a/c zones from a central compressor/condenser setup. This included a big bank (48v I remember) of lithiums to run the air conditioning, more lithium batteries for the house bank. A big arch fabricated to carry a lot of solar panels. Engine alterations to manage two big alternators. Lots of wiring. Etc etc. The work seemed to be well thought out and professionally installed. Cost? $160,000.00 US. This allowed them to run the air conditioning for 10 hours in most conditions.
A diesel generator would seem to be a better choice in my mind.

Im sorry... but they saw you coming 10 miles away.

[cdreid]

Originally Posted by Adelie

If you want AC off or solar/batteries you need the smallest possible unit.

1500BTU doghouse AC unit, draws about 300W. With this you can cool one small cabin for 8hr provided you insulate the walls and overhead. Assuming it runs constantly that’s 2400Whr, which at 12v is 200Ahr.

Storage: Since you don’t want to completely drain a battery, even LiFePo, you want about 240-250Ahr dedicated just to the AC.

Energy Production:
Using MPPT controllers rule of thumb is 1/3 of nameplate capacity equals average daily production in Ahr. You need at least 200Ahr divided by 1/3 equals at least 600W of panels dedicated to AC needs.

Listen to this guy. You dont need experience you need an engineer or someone who thinks like one.
Are you planning on staying in the bahamas? Or norway? Are you planning on having the boat sealed living in a slip or sailing? Are you planning on running it all day?
There are cats out there with 2kw of solar, plus wind and sea power. Those cats can run a full on home window ac unit 24/7 and half the boats weight is in lithium batteries. There are others with a couple solar panels and evaporative cooling or a dehumidifier. What you need to figure out is how much energy production you can pack on the boat.

[Seafarer7]

Originally Posted by LivingWhale

Exactly! Hoping real word experience chimes in .

I can run a Velair 16K BTU unit off batteries / solar via an inverter. In eco cooling mode it draws between 27 to 30 amps DC (about 360 watts). This includes the raw water circulation pump. No noticeable startup surge current and no need for hard/soft start devices.