Advice on best 12v desalination brands and units

[Matt Johnson]

Originally Posted by CaptainRivet

There is a reason they are cheap... Everything is proprietary and you pay an arm and leg for spare parts whichbyou regularly need.

Had one in my old ketch and wanted to use it daliy but was more broke then worked reliable, always something...

Now a HP watermaker UC35 tronic, works like a charm daily, fully made of V4A stainless and no proprietary parts besides the automatic valve for which I have a non proprietary manual valve too to replace or bypass if fails. Costs a fortune new but i got it used freshly overhauled for 3000. no maintenence beside filter and oil change every 600h.

Have you had one? Besides the membrane, everything is inexpensive and easy to replace in the Katadyn watermaker. I've rebuilt at least a dozen of them. And by rebuild I mean just a seal set replacement - that's about all there is to do on these.

[newhaul]

Originally Posted by CaptainRivet

There is a reason they are cheap... Everything is proprietary and you pay an arm and leg for spare parts whichbyou regularly need.
Had one in my old ketch and wanted to use it daliy but was more broke then worked reliable, always something...
Now a HP watermaker UC35 tronic, works like a charm daily, fully made of V4A stainless and no proprietary parts besides the automatic valve for which I have a non proprietary manual valve too to replace or bypass if fails. Costs a fortune new but i got it used freshly overhauled for 3000. no maintenence beside filter and oil change every 600h.

Well I have to once again disagree with you . Yes the membrane is specific to the unit so proprietary but as to cost well no not a significant cost difference and I have not experienced any issues with mine . Remember I live in a different country from you.
Things have changed significantly in the last couple or so years since the buyout by spectra.

Another thing you seem to forget we don't all sail on boats that are huge. Mine is 29 ft so size of each item I place on it is a significant concern.

[newhaul]

Originally Posted by Matt Johnson

Have you had one? Besides the membrane, everything is inexpensive and easy to replace in the Katadyn watermaker. I've rebuilt at least a dozen of them. And by rebuild I mean just a seal set replacement - that's about all there is to do on these.

The costs have cgone down significantly since spectra purchased Katadyn.
And buying from Tellie we get a price break as well.

[CaptainRivet]

Originally Posted by newhaul

Well I have to once again disagree with you . Yes the membrane is specific to the unit so proprietary but as to cost well no not a significant cost difference and I have not experienced any issues with mine . Remember I live in a different country from you.
Things have changed significantly in the last couple or so years since the buyout by spectra.

Another thing you seem to forget we don't all sail on boats that are huge. Mine is 29 ft so size of each item I place on it is a significant concern.

Well i had constant trouble with mine... Seal kit is 170Euro, needed 2 in 1.5 years but just 3 seals from that kit, this pressure relief valve broke twice..not only membrane is proprietary, nearly everything... more then 500Euro in 1.5 years...then you need to order which can take long and/or gets expensive on islands....
Would have ripped it out, which the new owner then did after it broke on him again.
Same with a buddy boat who replaced it with a Schenker 30. Seems there are 40E units that run for years and other break constantly...
For 165Euro I get a complete new high pressure pump with seals for my hp and not just a set of rubber seals... that cost below 10Euro when not proprietary.
Size constraints were never a criteria here till now. Yes 40e is very small and with 29ft it is very seldom to have a watermaker and the 40e most likely the only one fitting. my ketch was 40ft which is small nowadays.
The HP UC35 is very compact too and would fit in most small size boats too, eg also half size 3048 Dow Chemicals membrane. Have not much space where a watermaker fits well and is well accessible either,bilges are too low...

[Mike OReilly]

I've not heard much criticism around the quality or reliability of the PowerSurvivors. The proprietary nature of some parts, yes, but I can't recall reading about reliability issues before. So that's news (to me).

The criticism I hear about the 40E is the small volume it produces. But that is the design.

There appears to be an increasing number of options available on the watermaker market. That's good. When/if I get around to buying one, I'll have more choices to be confused by .

[CaptainRivet]

Originally Posted by Mike OReilly

I've not heard much criticism around the quality or reliability of the PowerSurvivors. The proprietary nature of some parts, yes, but I can't recall reading about reliability issues before. So that's news (to me).

The criticism I hear about the 40E is the small volume it produces. But that is the design.

There appears to be an increasing number of options available on the watermaker market. That's good. When/if I get around to buying one, I'll have more choices to be confused by .

The 40E has many weak spots:
- high pressure valve, easy to break and u need several as spare, each 50Euro
- piston
- small size hose easy clogs up
- rubber seals (needed 3 of the set, you cannot get them per piece) each set is 170Euro
- prefilters are not standard, get 5 standard for one pentair P30
- pressure is too low for having a charcol filter before water goes into tank.
- strange noise, these clicking noise is not easy to damp
- even for solo sailor you need to run it 2-3h per day=noise

[newhaul]

Originally Posted by CaptainRivet

The 40E has many weak spots:
- high pressure valve, easy to break and u need several as spare, each 50Euro
- piston
- small size hose easy clogs up
- rubber seals (needed 3 of the set, you cannot get them per piece) each set is 170Euro
- prefilters are not standard, get 5 standard for one pentair P30
- pressure is too low for having a charcol filter before water goes into tank.
- strange noise, these clicking noise is not easy to damp
- even for solo sailor you need to run it 2-3h per day=noise

What brand are you a dealer for?

Remember you are in Europe many on here are in the North American and Central American cruiser area parts are not as expensive nor hard to aquire.
As I said myself I have not had any issues with my unit and only needs to run for 4 or 5 hours every few days and don't even notice the sound after the first time you run the unit each crossing. The prefilters are standard 2 inch by 12 inch . Sorry you had so many issues . As to the seals failing prematurely it's usually the installers error usually lack of cleanliness . It has tight clearances so the slightest dust will cause issues.

[Mike OReilly]

Originally Posted by CaptainRivet

The 40E has many weak spots:
- high pressure valve, easy to break and u need several as spare, each 50Euro
- piston
- small size hose easy clogs up
- rubber seals (needed 3 of the set, you cannot get them per piece) each set is 170Euro
- prefilters are not standard, get 5 standard for one pentair P30
- pressure is too low for having a charcol filter before water goes into tank.
- strange noise, these clicking noise is not easy to damp
- even for solo sailor you need to run it 2-3h per day=noise

As I said, I have no experience with any WM, so I'm not disputing your comments. But given how common the 40Es are, I find it a bit odd yours is the first major criticism I've heard.

[Apocalyptism]

Originally Posted by roam

I have a 12v rainman. It's pretty convenient and the solar will run it and still have excess energy to to charge the batteries. The negative to the 12v unit is the low flow (8 gph) means you have to run it for hours at a time to be worth the trouble. You'll run it for 20-30 minutes just to make enough water to flush it when you're done.

It amazes me that solar power could ever be enough to power this. How many solar panels do you have?

[newhaul]

Originally Posted by Apocalyptism

It amazes me that solar power could ever be enough to power this. How many solar panels do you have?

https://www.rainmandesal.com/12vdc-watermaker/
With recent advancements batteries, solar, and wind power, it is easier than ever to have sufficient useable amp-hours available for running your appliances.

Our 12VDC system requires 410 watts, or about 30 amps, to operate.

A lot more power than my 4.5 amps and 1.5 gph

Theirs look to be about 4 amps per gallon per hour. But the price tag. Yuck
4500. The extra 4 grand I saved will pay for a lot of membranes and maintance kits .

[noelex 77]

The Rainman 12v system will require over 3 times the power per unit of water than most of the energy recovery water makers.

This amount of power is fine if using a generator, but it is tough to produce if you are expecting to run the boat on solar power alone.

[Pizzazz]

Originally Posted by Kd9truck

Hi Mike, I am not planing the upgrade based on current usage, I am anticipating longer and more frequent trips, I am taking my time, I am slowly prepping my boat for longer cruse times

It is commendable that you are trying to equip your boat for long range cruising. In my mind, there are two ways to go:

1) Primarily AC-powered boat. You get a small diesel generator (should be fine on a 44 foot boat) and pick all your appliances accordingly. This includes water maker, automatic washing machine, dishwasher, coffee maker, charging the batteries, etc. I would even add electric kitchen. You will still need a small inverter, so that you do not need to run the generator to make coffee in the morning or watch TV at night. The biggest benefit here is that you have one fixed investment and then everything else is cheap, household based stuff that you can get anywhere.

2) Primarily solar-based boat. You stay at 12/24V for as long as possible and start this viscous cycle of more batteries, more solar, not I have excess solar most of the time but need to size for cloudy days, OK, more batteries, then lithium batteries, the a 12V energy recovery water maker for $8k, vs a 120V for $3k, a bigger inverter, etc. Then you get to the AC stage, and you cannot do AC without a generator, so you go back to 1).

My advice would be to choose one of these options, starting from your power generation style, then add appliances.

[newhaul]

Originally Posted by noelex 77

The Rainman 12v system will require over 3 times the power per unit of water than most of the energy recovery water makers.

This amount of power is fine if using a generator, but it is tough to produce if you are expecting to run the boat on solar power alone.

Please elaborate as I have not seen any that produce water at much below 3 amps per gallon .

[newhaul]

Originally Posted by Pizzazz

It is commendable that you are trying to equip your boat for long range cruising. In my mind, there are two ways to go:

1) Primarily AC-powered boat. You get a small diesel generator (should be fine on a 44 foot boat) and pick all your appliances accordingly. This includes water maker, automatic washing machine, dishwasher, coffee maker, charging the batteries, etc. I would even add electric kitchen. You will still need a small inverter, so that you do not need to run the generator to make coffee in the morning or watch TV at night. The biggest benefit here is that you have one fixed investment and then everything else is cheap, household based stuff that you can get anywhere.

2) Primarily solar-based boat. You stay at 12/24V for as long as possible and start this viscous cycle of more batteries, more solar, not I have excess solar most of the time but need to size for cloudy days, OK, more batteries, then lithium batteries, the a 12V energy recovery water maker for $8k, vs a 120V for $3k, a bigger inverter, etc. Then you get to the AC stage, and you cannot do AC without a generator, so you go back to 1).

My advice would be to choose one of these options, starting from your power generation style, then add appliances.

Just to let you know the watermaker price difference is negligible in the long term . A new rainman 12vdc-watermaker is 4500 the 120vac version is 4,000
This is from their website

And now days 500 usd won't run a diesel generator for very long

[noelex 77]

Originally Posted by newhaul

Please elaborate as I have not seen any that produce water at much below 3 amps per gallon .

You need an energy recovery water maker to achieve this low power consumption. The Spectra units use about 4-5w per L or 14.5-16 w per gallon depending on the model. (This would be about 1.25A @12v per gallon and less at a typical battery voltage which will be be higher than 12v).

Rainman claim 410w per gallon.

My previous Spectra Ventura model slightly beat the published specifications so their data is realistic.

These significant differences illustrate why energy recovery technology is important if you want to run the water maker on a boat without a generator.