Selecting A Water Maker-a Lesson Learned The Hard Way. Maybe This Will Help Someone?

[a64pilot]

Originally Posted by downunder

You need to read the thread. Certainly seems an option.

It's simply the physics of the thing, to actually run a compressor off of Solar, you need at least 3 KW of Solar. Now you can run it off of your bank and Solar maybe, but then you have a depleted bank.
I'm not trying to be argumentative, but it is the same as running your airconditioner off of Solar or using Solar to provide propulsion, sure you can do it, but you have to have more Solar than I have ever seen any of us have, or you run it off of Solar and your bank and at the end of the day the sun goes down and you have a depleted bank, or you run your engine, but then you would be better off running a generator.

Another way to look at what I am saying is yes, you can run dive compressors etc off of Solar as long as you have massive excesses of Solar, and not many of us do.

There is just no free lunch

[downunder]

A64,

I think you miss the point. Until I saw this thread I thought I was necessary to have a big genset to run the small Bauer compressor. Bauer suggest 8KVA to be safe.

https://diy-yachts.com/forum/viewtop...9cfec1eecc8c22

Obviously if you are running a dive operation or carying 4 divers on a cat diving all day having a diesel genset or petrol compressor is necessary.

In my situation which is similar to yours, cruising full time with ocassional guests/dive buddys with either a small genset such as yours or perhaps a Honda backup and 1.2KW of solar this approach offers an alternative approach.

If you read the thread the key is that the start up loads of the variable speed drive are much,much lower making it possible to start and run the compressor on a 3000W 240 volt inverter. The OP subseuently did a trip of a month or so from Cairns up to PNG and back, diving and running his watermaker from is solar and engine alternators.

Other have used the option of VSD drives for their watermaker successfully such as Sail/surf Roam cruising the Pacific on a 48ft cat without generator.

https://www.instagram.com/p/BEzvufVpevk/

Certainly an option for limiting the need for a large genset. It is the principle used by the more efficient air con inverter systems.

[a64pilot]

OK I get that, If it can reduce the start up surge then I can see the benefit.
So why don't the compressor manufacturers offer this I wonder?
If I could run a Bauer off of my 3.5 KW gen I would buy one over a compressor that needed a bigger generator

[daletournier]

Originally Posted by downunder

A64,

I think you miss the point. Until I saw this thread I thought I was necessary to have a big genset to run the small Bauer compressor. Bauer suggest 8KVA to be safe.

https://diy-yachts.com/forum/viewtop...9cfec1eecc8c22

Obviously if you are running a dive operation or carying 4 divers on a cat diving all day having a diesel genset or petrol compressor is necessary.

In my situation which is similar to yours, cruising full time with ocassional guests/dive buddys with either a small genset such as yours or perhaps a Honda backup and 1.2KW of solar this approach offers an alternative approach.

If you read the thread the key is that the start up loads of the variable speed drive are much,much lower making it possible to start and run the compressor on a 3000W 240 volt inverter. The OP subseuently did a trip of a month or so from Cairns up to PNG and back, diving and running his watermaker from is solar and engine alternators.

Other have used the option of VSD drives for their watermaker successfully such as Sail/surf Roam cruising the Pacific on a 48ft cat without generator.

https://www.instagram.com/p/BEzvufVpevk/

Certainly an option for limiting the need for a large genset. It is the principle used by the more efficient air con inverter systems.

But its still drawing approximately 300amp dc? Isnt it? This is a huge current draw on batteries and needs to be replaced. Obviously depends on time it take to fill tanks regarding battery soc.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[downunder]

Originally Posted by a64pilot

OK I get that, If it can reduce the start up surge then I can see the benefit.
So why don't the compressor manufacturers offer this I wonder?
If I could run a Bauer off of my 3.5 KW gen I would buy one over a compressor that needed a bigger generator

That's the real advantage that I can see.

Just replace the electric motor with 3 phase VSD as Grouper suggests in his thread. Don't ask me any of the technical electrical stuff. Talk to him. All I know is it works and your genset would handle it.

[downunder]

Originally Posted by daletournier

How long does it take to fill a tank? Its a huge battery draw, what size is your bank and solar system? Sorry if I missed this as I haven't read the whole thread and cant open the above link in this phone.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

Not my vessel and I think his solar was at least 750ah. I agree you would have to carefully manage the battery bank and only use compressor on sunny days and perhaps with motor running.

I can't answer the tech detail but I do know he (Grouper) did a trip from Cairns to PNG and back using the system. Clearly the system he is using offers some options other than a larger genset. Roam the 48ft Spirited 480 recently did a 5-6mth trip into the Pacific using the system on their watermaker.

Cheers

"The good thing is now i have full control of the RPM so i can slow it down a bit if i want to and the more i slow it down the more quietly it runs and the less power it uses - at 30hz it runs very quietly and uses nearly half the power... 35hz seems to be a good compromise on speed to fill a tank and noise levels are tolerable.

At full speed it fills a medium size tank in 20mins from empty, 15 mins if there is 50BAR already in it. Its output at full speed is 100L/min. So a 10L tank (85cu ft imperial) is 20 mins to input 200BAR."

[toddster8]

To start with an indirect observation...
In my Mother's final months, when she required supplemental oxygen, she was provided with a small compressor unit that both separated O2 from air and filled her high-pressure cylinders. It was (relatively) quiet and ran on any 20-amp 110V outlet. I kept looking at that thing and wondering why they don't make a SCUBA compressor like that? From the sounds, I'd guess that it had a small conventional oil less compressor and a balanced-piston high-pressure pump. (Kinda like that "shoebox compressor" that one guy sells for paintball tanks. Only his isn't oilless.) Sure, it took all day to fill a tank, but if you just want to dive a couple of tanks a week, while cruising, that's all you'd need! I'd love to get one of those medical units in the shop and open it up for a look...

As I understand it, this sort of pumping scheme is the same general reason that the Katadyn watermaker uses 4 amps to do the same thing that others require 20 or 30 amps for.

[Wolverine6300]

Ok, I read every post in this thread! Rich ( cruise Ro) it was nice meeting you on Monday at the boat show">Miami boat show. You were my first stop. Still not sure which way to go with water maker. So looking for a little more input. Here's my situation. I have a Gozzard 44 with 690watts of solar charging LiFePo4 batteries 400ah through a outback controller. I also have a Northern light 6kw genset. I cruise 4 to 6 times a year for 2 to 6 weeks at a time. We like hot showers! Dilemma is 12 volt or 110volt. I'm a firefighter and electrician and do 95% of the work on my boat myself.

[SV THIRD DAY]

Ah....well LiFePO4 batteries makes it a different animal because you can run the 1100W motor of the SM20 or SM30 through a 2000W inverter pretty easily. I do that myself and have several clients doing the same thing. Use the Generator when at anchor or whenever you are running it to make larger quantities of water and then when the generator is not in use, you have the option of running off the LiFePO4 batteries. Unlike Lead Acid, the 90A 12v DC load won't crush your LiFePO4 batteries so it opens up a new world of possibilities...we love ours and would never go back to lead!

I enjoyed the show...but it's nice to be back aboard the boat in Morro Bay and as my wife says for me to start working on the Boat To Do List!

[canadian cat]

Can I start a new water maker case study.

I have a larger cat and the genny is shot. I don't want another one gas or diesel. I think I can fit 1200-1500W of solar. I am going to switch to LifePo4 bank of 1200amp/hr. with Leece Neville 160 amp alternators on each engine.

I have a family of four with guests to 6-8 total on the rare occasion.

What water maker would you suggest? I would really like to not run a genny. Will this work?

[SV THIRD DAY]

Originally Posted by canadian cat

Can I start a new water maker case study.

I have a larger cat and the genny is shot. I don't want another one gas or diesel. I think I can fit 1200-1500W of solar. I am going to switch to LifePo4 bank of 1200amp/hr. with Leece Neville 160 amp alternators on each engine.

I have a family of four with guests to 6-8 total on the rare occasion.

What water maker would you suggest? I would really like to not run a genny. Will this work?

LiFePO4 batteries are still relatively new, but we do have about a dozen clients with our 30 gallon per hour water maker that don't have a generator and run the 1.0Hp motor exclusively off of their 2000w inverter. They also have 600W+ of solar and high output alternators. So it's easily doable with LiFePO4 batteries. Of course a smaller 12v output water maker would work also, but once you start having the larger crews and boats, the ability to make a lot of water quickly becomes a plus. While motoring, your alternator could provide the 90A DC 12v load to run the water maker or with the amount of solar you have you could darn near cover the water maker load from solar.

Here's a link to download the SM30 water maker manual:
www.cruiserowaterandpower.com/uploads/sm30.pdf

Cheers

[44'cruisingcat]

Originally Posted by SV THIRD DAY

The only way I see a 12v water maker working is if you have an energy recovery pump like a Spectra, again unless you have a LOT of solar or LiFePO4 batteries.

We got by with 600 Watts solar and AGM batteries running a Little Wonder 12 volt watermaker for about 5 years. Having 800 Watts solar makes it easier though.

On reliability, I recently considered our normal water usage, and figure our unit has by now made between 60,000 and 80,000 litres of fresh water, with nothing more than routine maintenance. Most of that has been powered by solar panels.

[SV THIRD DAY]

Originally Posted by 44'cruisingcat

We got by with 600 Watts solar and AGM batteries running a Little Wonder 12 volt watermaker for about 5 years. Having 800 Watts solar makes it easier though.
.

That's my point exactly.
600W of solar is a LOT for the average cruising boat. I wasn't truly "off the grid with solar" on our boat until we made the leap up to 1000W. We headed out cruising with 260W, upgraded to 480W, anther upgrade to 700W and then once we hit 1020W...boom...I really didn't have to run the generator ever again just for power. We didn't even try to run a water maker on 12v to handle our crews water needs of on average 25gals per day. But not everyone has a crew of 4 and a fresh water anchor chain rinse down to keep the anchor locker from smelling up my son's v-berth and then complaining...

[roetter]

Originally Posted by Capt.Don

You folks with the 12v Spectra -- which model do you have? How often do you run it, how many gallons do you mak, and how do you flush the 40e/80e?

Don

Newport 400, 19 GPH, once to twice a week for 4-6 hours, auto flush at the end. All run on solar. Still get 30-40 amps into the batteries while it is running.

[sailjumanji]

Jeez you guys have a lot of solar! Just so that someone knows you don't need that much to run a watermaker, we have a Spectra 150D and two 120-watt solar panels. (JT "Tellie" actually helped me commission the Spectra, although he didn't sell it to me.) Our experience with it cruising for a couple of months in the Bahamas last year was that typically we made 7 GPH using 8 amps. We typically ran in the middle of the day, when the solar panels could fully cover the load of the watermaker, and batteries were charging at 13 volts. We would run for about 4 hours, which made 28 gallons, and then used 3 gallons for a flush. So net to the tank was 25 gallons. We used 10 gallons per day, so would run the watermaker every 2-3 days. (We would also run it if we were motoring long distance, as the twin 9.9 hp outboards have small alternators but big enough to cover the watermaker load.)
,
We carried a Honda 2000 generator as a backup, but only ran it for four hours one day during the entire trip. (Very cloudy day, sailing, and forgot I had turned on the watermaker earlier and had it running most of the day. Batteries got low so I topped them up with the gen when we got to anchorage.)

Watermaker was pickled with propylene glycol (Pure Oceans -50 deg F) in June of last year, and will be that way for about 1-1/2 years before recomissioned on our next cruise. I'm hoping that is not too long to be pickled. Other option is to restart it this summer, and then pickle it again. Tellie, any thoughts on what would be best?