Want To Buy: watermaker

[tomtriad]

Looking for a low power consumption 12 volt watermaker, like a Katadyn 40E.

[wrwakefield]

Originally Posted by tomtriad

Looking for a low power consumption 12 volt watermaker, like a Katadyn 40E.

Hi Tom,

I think you will find that the lowest 12VDC power consuming [i.e., highest potable water production per 12VDC amp-hours consumed] watermaker brand is Spectra with their Clark pumps. [This I glean from reading and from past posts on this topic. And I own one...]

As an example, ours uses about 1.2AH/gallon produced. We usually run it when motoring, so that means it is being fed 14.2+ volts DC during that period. [i.e., optimum production.]

In case this helps.

Cheers!

Bill

[tomtriad]

Thanks. I'll check out Clark. I run on solar which will produce around 13 v when batteries are topped up. Outboard (boat motor) generates 14.5 but is rarely used. Do you think it will work?

[a64pilot]

You need in my opinion to get an energy budget together, that is determine how much AH you use, and how big are your charge sources, then get a hold of Tellie, the resident Spectre expert here. Making water is energy intensive, the Clark pump apparently is orders of magnitude more efficient though than most any others
Need to know size and type of battery bank, number and size of Solar panels etc., location helps as more Sunlight in S fl than in Maine this time of year

[wrwakefield]

Originally Posted by tomtriad

Thanks. I'll check out Clark. I run on solar which will produce around 13 v when batteries are topped up. Outboard (boat motor) generates 14.5 but is rarely used. Do you think it will work?

Hi Tom,

Generally speaking, you should be fine, but there are a lot of variables...

A64 is giving you very good advice for your next steps: figure out your energy budget and energy storage/production limits, and talk to experts about the watermaker.

Let us know what you decide to do.

Cheers!

Bill

[a64pilot]

Let me tell you what I'm thinking, if you are close to being maxed out power wise now, that of course means your going to have to add some significant power production.
If that is true, then you at least two options, increasing DC production if possible or going with a suitcase generator, or maybe even a stand alone watermaker.
A lot will depend on how much money you have available to spend.

Got a gut feeling since you talk voltage of batts and outboard alternator, you have a lot of reading to do.
I believe small outboards unfortunately are not a very good power source, but big ones like my old Verado are. So need to know it's output in amps, not volts too.

You have Solar?

[Boatguy30]

Tom knows a lot about his boat,my it maybe not so much about electricity.

Anyway, the spectra is a better way to go but VERY expensive. However the Katadyn have gotten up their doubling in price or so in last 10 years.

I purchased a used/rebuilt Clark pump and will be putting something together with it next year. Tell you about it in the Bahamas. The other nice thing is you can have a wash down pump with little extra plumbing and no extra pumps.

[Hoghead]

Where are you
I am upgrading my Village Marine 12V watermaker with a bigger engine driven pump and 4 x 40 membrane so selling all the key Little Wonder components. The boat is in Fiji however

I will be selling all the key components in a lot:,
Village Marine Titanium head high pressure pump
Village high pressure hoses
Jabsco low pressure pump
Village membrane and housing
HP regulator
output flow meter
Even a Groco bronze strainer in you need one

All you would need are readily available filters, low pressure valves, and plumbing.
Removing this in Feb, and could carry to the Philippines when I move the boat this season.

[tomtriad]

I have three 85 watt solar panels and two 105 AH Lifeline AGM batteries; I doubt there is sufficient capacity to power the Village watermaker which requires 13.8 volts according to the technical manual (solar panels can achive this mid day when sunny once the house batteries are topped up). I'm loathe to install a wind turbine, and I have only a 9.9 hp Yamaha 4 stroke outboard motor for auxilliary - insufficient to run a watermaker. Perhaps additional solar panels will result in enough surplus to consider a watermaker.

I'm located in Gloucester, MA and the boat is currently moored in Stuart FL awaiting my return in early January to sail over to the Bahamas for the winter.

[a64pilot]

Enough Solar and maybe a bigger battery bank, and you could do it, certainly.
But there is a point to where you give up as it gets so expensive and just go with a Honda Gen and an inefficient 120V system, it is less efficient, but the Honda doesn't care and you can make I believe 30 GPH with a Honda being the power source.

[Hoghead]

I have a Honda 2000 @ 110V and it only puts out 13.5A. Given the inrush starting current of a 110V motor I could not start a decent sized HP watermaker pump, so going to engine drive off the genset.
The Honda would however charge the battery bank while the Little Wonder was wondering

That is why the Little Wonder and Honda are for sale

Originally Posted by a64pilot

Enough Solar and maybe a bigger battery bank, and you could do it, certainly.
But there is a point to where you give up as it gets so expensive and just go with a Honda Gen and an inefficient 120V system, it is less efficient, but the Honda doesn't care and you can make I believe 30 GPH with a Honda being the power source.

[SV THIRD DAY]

Originally Posted by Hoghead

I have a Honda 2000 @ 110V and it only puts out 13.5A. Given the inrush starting current of a 110V motor I could not start a decent sized HP watermaker pump, so going to engine drive off the genset.
The Honda would however charge the battery bank while the Little Wonder was wondering

That is why the Little Wonder and Honda are for sale

Simply not true, but a common misconception.
Your Honda 2000 generator would run the 1.0Hp motor (9.3A at 115V) on our 20GPH or 30GPH water maker AND STILL have power left over to run a 40A DC Battery Charger. Starting the motor is not a problem either since the water maker is not started under load. We have hundreds of them doing it around the world. Water and Power at the same time is a beautiful thing....

There is no way I would do an engine drive off the genset over a clean/easy/simple electrical motor powered by the Honda, although I sell both. The simplicity of the Honda/Electrical motor approach is hard to beat. If your Honda dies or gets stolen...easy...make water with your alternator running through a 2000W inverter. What we do is make water using the Honda while charging the batteries when at anchor, and then through the 2000W inverter when motoring.

[Hoghead]

My key phrase was "decent size" HP pump.
I now have a 4.2 UGS/Min General Pump that would take 2.58 HP at 900 psi. I will likely run it at 900 - 1000 psi The inrush current to start a 3 hp electric motor was the issue even for my Next Gen genset

Direct engine drive is my only choice, although I would have loved the simplicity of electric motor drive, but not prepared to sacrifice output

What is the inrush starting current for your 1 HP motor? The electric motor takes a lot of current to start and normally close or equal to, the locked rotor rating

Originally Posted by SV THIRD DAY

Simply not true, but a common misconception.
Your Honda 2000 generator would run the 1.0Hp motor (9.3A at 115V) on our 20GPH or 30GPH water maker AND STILL have power left over to run a 40A DC Battery Charger. Starting the motor is not a problem either since the water maker is not started under load. We have hundreds of them doing it around the world. Water and Power at the same time is a beautiful thing....

There is no way I would do an engine drive off the genset over a clean/easy/simple electrical motor powered by the Honda, although I sell both. The simplicity of the Honda/Electrical motor approach is hard to beat. If your Honda dies or gets stolen...easy...make water with your alternator running through a 2000W inverter. What we do is make water using the Honda while charging the batteries when at anchor, and then through the 2000W inverter when motoring.

[SV THIRD DAY]

First the dreaded inrush is easily handled by the Honda 2000 generator, so its not as bad as you think...22A for a millisecond and then down to 8.3A and slowly raising up to 9.3A as the pressure of the system is increased from. 150 to 800psi.

Second, a 4.2gpm general pump needs a 2.5hp motor, I know because we have hundreds of those combinations in the field, so why over power the pump with a 3hp? It doesn't gain you anything except extra weight, cost and power?

You may want the extra fresh water production of 45-48gph with the 4.2gpm/2.5hp pump and motor set-up from your 4" x 40" membrane and that's a good reason to go that way, but it is certainly not the most efficient way to go. Not when you can make 33gph using less than half the HP with a 1.0 HP motor and two standard off the end 40" x 2.5" RO membranes.

There is a reason that the 4" x 40" RO membranes are not found in many water makers and that is because even with the 4.2gpm pump you WILL be below the minimum brine flow specs for that membrane. What does that mean...premature membrane scale fouling and death. The minimum brine flow DOW recommends for that membrane is 4.0gpm, you will be at about 3gpm.

At the risk of sounding like a know it all....
I want to address one more item you mentioned to prevent it from becoming a cruise rumor fact. System operating pressure. 900psi is HIGH and above that is membrane danger land. You work the membrane too hard and it leads to a premature death. Sure you get a little bit more fresh water production going from 800psi to 900psi but the life span damage to the membrane just isn't worth it to me anyway.

Cheers.

[Hoghead]

Originally Posted by SV THIRD DAY

First the dreaded inrush is easily handled by the Honda 2000 generator, so its not as bad as you think...22A for a millisecond and then down to 8.3A and slowly raising up to 9.3A as the pressure of the system is increased from. 150 to 800psi.

Second, a 4.2gpm general pump needs a 2.5hp motor, I know because we have hundreds of those combinations in the field, so why over power the pump with a 3hp? It doesn't gain you anything except extra weight, cost and power?

You may want the extra fresh water production of 45-48gph with the 4.2gpm/2.5hp pump and motor set-up from your 4" x 40" membrane and that's a good reason to go that way, but it is certainly not the most efficient way to go. Not when you can make 33gph using less than half the HP with a 1.0 HP motor and two standard off the end 40" x 2.5" RO membranes.

There is a reason that the 4" x 40" RO membranes are not found in many water makers and that is because even with the 4.2gpm pump you WILL be below the minimum brine flow specs for that membrane. What does that mean...premature membrane scale fouling and death. The minimum brine flow DOW recommends for that membrane is 4.0gpm, you will be at about 3gpm.

At the risk of sounding like a know it all....
I want to address one more item you mentioned to prevent it from becoming a cruise rumor fact. System operating pressure. 900psi is HIGH and above that is membrane danger land. You work the membrane too hard and it leads to a premature death. Sure you get a little bit more fresh water production going from 800psi to 900psi but the life span damage to the membrane just isn't worth it to me anyway.

Cheers.

Rich
Thank you for your comments and advise.

I could have used a 1 HP motor as you say, but I had this before in a different boat, wanted more flow this time around. In ignorance perhaps I do not need it but I wanted it hence the 4.2 USG/Min HP pump. I am 220V so I could not find a suitable direct mount 2.5 HP (actually 2.58) motor, therefore the 3 HP and its dreaded inrush current. My Next Gen 5.5 only puts out 21A at 220V and not up to the task of starting the motor.
I could see no other way other than engine drive off the genset

I am using a Hydraunatics SWC5 "low fouling technology" membrane rated max 1200 psi in a Codeline housing rated at 1000 psi. I had thought that 900 psi operating pressure would be conservative given the membrane rating?

I am not clear on how you down-rate the 4.2 pump to 3 USG/Min? I am turning the pump at a constant 1750 rpm and if the specs are correct it will put out 4.2

I do not see a min flow rate for this membrane and only a max rate of 16 USG/Min. All I can do now is hope that my flow is not too low..............

I went with the single 4 x 40 to make my life simple and it was cheaper than 2 ea. 2.5 x 40's. If the membrane prematurely fouls time will tell if this was a penny wise and pound foolish decision
Since I am engine drive at the pump, cost for the 12V clutch VS the electric motor is about the same.

OTOH your approach with a 1 HP motor and 2 ea x 2.5 x 40 membranes is an acceptable output and overall would be about the same cost. Cheaper if I used the existing Honda
I only wish I had had this discussion a month ago