Watermaker comparison worksheet

[Dirk Williams]

Good morning, my boat is a smaller boat. A Hallberg RASSY 33 mistral, the origional owner appears to have been an avid coastal cruiser, and currantly has a three battery set up, charged by a very large alternator, imto a battery charger.

It's my goal to source the boat with at least 600 watts of solar, maybe 800, I don't think theirs is such a thing as to much power on a boat. I can see a wind gen on board before heading to Alaska.

And then the Honda gen set. One of the problems in trying to work thru is weight, per a question I asked last week, is how much, is to much, above and beyond for equipment in and on the boat.

Stuff, like chain and rode, anchors, water makers, solar towers, a gen set. Etc etc. how to keep the weight down yet sail,comfortably and safely.

I currantly don't have the ability to power a water maker, The boat has a 52 hp Perkins 4-108m I rebuilt within the past 90 days. ,I'd considered using this motor as the power source, but have decided that the motor compartment is just not big enough for stuff.

Solar and wind power are in my future. As for the water maker this one device is a game changer for me. The ability to make water is key for me. ,

I've read about DC power, with 800 what solar systems, after chatting with the water maker company owner, and my location " west coast" solar on off days are not realizable enough and the battery pack would be overly expensive.

The one thing I'd like to change in my plans is a Honda diesel,gen set, don't even know if Honda makes one. I'm guessing they do. I can see me eventually purchasing one specific to the boat..

I'd like to get away from gas and run everything diesel and propane.

Thank,you.

Merry Christmas.

Dirk

[Pizzazz]

Originally Posted by Jsta_Rebel

I have a 4" x 40" membrane on my watermaker that runs at 35% recovery and has for five years without plugging up. Of course it's flushed with fresh water after each run. Larger systems run at up to 45% recovery with membrane life expectancy at 7 years with proper pre treatment and good SDI's. I have data if you would like to see.

Dear Rebel,

This is good to hear. I have been focused on smaller 2.5x21" membranes and assumed that you can drive them at max 20% recovery (per Dow's spec sheet). I can imagine that putting two such membranes in series will give you around 35% recovery so getting the longer membrane 2.5x40" should accomplish just that. In this case, we can drive a 2.5x40" membrane at 0.5 gpm (1/3 hp, 27 amps) and get 35% recovery or 12 gph at about 2 amps/gallon. This is getting into Spectra territory.

It would be helpful to get your data on the flow rates and the motor/pump combinations you are using. I am totally for driving this membranes to the highest possible recovery rate (then either flush, pickle regularly or just replace every three years at $200/membrane) as this gives greater efficiency.

Learning something new everyday. Although, if this was the case, why would the DC watermaker vendors not do the same thing? It seems that most have settled on a smaller membrane at 20% recovery at 4-6 amps/gallon. Something does not compute. If you could lower the DC max current, lower the amps/gallon to 2-3V at the expense of more frequent membrane replacement that would appeal to cruisers much more I believe.

Happy holidays,
Pizzazz

[jcapo]

Higher flow rate = lower recovery = longer membrane life.

My .55gph pump at 800psi delivers 13 to 16gph of product depending on salinity and battery voltage. That's 30+% recovery from a 2.5x40" sw-2540 membrane. Going on 3 years so far and if I have to replace the membrane its less than $200.

This is a Wanner pump on a 1/2hp 12vdc Leeson motor. Current is about 35amps with the feed pump.

[Tellie]

Originally Posted by Dirk Williams

Good morning, my boat is a smaller boat. A Hallberg RASSY 33 mistral, the origional owner appears to have been an avid coastal cruiser, and currantly has a three battery set up, charged by a very large alternator, imto a battery charger.

It's my goal to source the boat with at least 600 watts of solar, maybe 800, I don't think theirs is such a thing as to much power on a boat. I can see a wind gen on board before heading to Alaska.

And then the Honda gen set. One of the problems in trying to work thru is weight, per a question I asked last week, is how much, is to much, above and beyond for equipment in and on the boat.

Stuff, like chain and rode, anchors, water makers, solar towers, a gen set. Etc etc. how to keep the weight down yet sail,comfortably and safely.

I currantly don't have the ability to power a water maker, The boat has a 52 hp Perkins 4-108m I rebuilt within the past 90 days. ,I'd considered using this motor as the power source, but have decided that the motor compartment is just not big enough for stuff.

Solar and wind power are in my future. As for the water maker this one device is a game changer for me. The ability to make water is key for me. ,

I've read about DC power, with 800 what solar systems, after chatting with the water maker company owner, and my location " west coast" solar on off days are not realizable enough and the battery pack would be overly expensive.

The one thing I'd like to change in my plans is a Honda diesel,gen set, don't even know if Honda makes one. I'm guessing they do. I can see me eventually purchasing one specific to the boat..

I'd like to get away from gas and run everything diesel and propane.

Thank,you.

Merry Christmas.

Dirk

Personally I would drop the Honda and use the money budgeted for the Honda an add it towards the budget already intended for a watermaker. Not sure who you are talking to as far as a watermaker company's. But it is true with most watermakers that even an 800Watt solar array will barely if at all keep up with the high energy demands. But a Ventura 150 or 200T would easily be powered by a 600-800 watt array. At 108 to 120 Watt hour even a 600 Watt solar array running at 1/3rd capacity would almost be twice the power generated to what is needed to run it. Also, it is going to be lighter and easy to install. I've never seen a 33' boat yet that you couldn't put even a larger watermaker on. This gives you three ways to power this watermaker. Certainly solar which will on good days produce far more than the Ventura watermaker will use leaving the difference to charge and power other electrical devices. When you are motor sailing this is also a perfect time to operate this watermaker as your alternator will put out far more power than the watermaker will need. Thirdly, you can operate it directly from your battery bank for two or three hours without putting a big dent in the battery charge. An AC unit is usually dependent on a generator. No generator no watermaker.

[Dirk Williams]

Rich, at cruise RO, west coast, I think San Leandro, I'd like to stay semi local. Being an Oregon sailor. A diesel,Honda 2000, would be way way down the road. Like replacing this Honda 2000 gas unit.

Dirk

[a64pilot]

The key to me is he said " I want to power one as quietly and efficiently as possible"
That is an energy recovery DC model, specifically some kind of Spectra.
An AC water maker is anything but quiet and efficient. I believe they are really for the person that is going to be running a generator anyway, so what not make water too?
Excuse me if I didn't get the quote exact, and I don't yet have a watermaker either, but in my case, I'm the guy that will be running a generator anyway, and can accept a loud, inefficient AC watermaker. Won't hear it over the generator, and I should have power to spare.

[Pete7]

Dirk, not sure you could mount 800w of solar on a 33 yacht. A 100w panel is 1m x .5m or there abouts, even with an A frame on the stern you are going to struggle, or end up with something about the size of a garage roof on her.

400w would be 2 panels on an A frame and two panels on the guard rails.

Btw we ditched our Honda 2000 and bought solar, the only down side is no hot water unless the engine has been run in the previous 24 hours, but can live with that. One interesting upside is that the anodes now last a lot longer because we don't plug into shore power or the Honda.

Pete

[PassportJoy]

Originally Posted by Capt.Don

With all the recent discussions comparing watermakers, does anyone have a comparison worksheet with make, model, 12vdc/110v, amps, gph (lph), size, cost, etc.?

Thanks

Don

My 2 cents... 7 years ago I bought and installed a Spectra Catalina 300 MPC. I did the comparisons of amps vs GPH and this one beat everyone out there producing almost 1 gallon per amp hour. What I didn't account for was the $ per gallon cost. Initial cost including installation $10,000, filters @ $11 each was about $50 for every 500 gallons of water. After 700 hours run time the membrane needed replacement and the high pressure pump needed rebuilding. In the "do over" world I would increase my fresh water tankage, filter dockside water, catch rainwater, and buy purified water as needed. Everywhere people are, drinking water is available. A water maker is a huge luxury!

[newhaul]

Originally Posted by PassportJoy

My 2 cents... 7 years ago I bought and installed a Spectra Catalina 300 MPC. I did the comparisons of amps vs GPH and this one beat everyone out there producing almost 1 gallon per amp hour. What I didn't account for was the $ per gallon cost. Initial cost including installation $10,000, filters @ $11 each was about $50 for every 500 gallons of water. After 700 hours run time the membrane needed replacement and the high pressure pump needed rebuilding. In the "do over" world I would increase my fresh water tankage, filter dockside water, catch rainwater, and buy purified water as needed. Everywhere people are, drinking water is available. A water maker is a huge luxury!

So let me get this straight you were using $11 per for prefilters and only getting ten gallons product water per filter. There seems to be something seriously wrong here .
On our Spencer we had a katadyn 35E and using it a lot we only needed to change prefilters every few thousand gallons of product water. And only 700 hours operation sounds like to me you were getting cheap filters for the expensive filter price.

[newhaul]

On my current islander I have a katadyn 35 manual unit hadn't converted it to power yet. With a mere 12 gallons tankage and no place to really add any its not so much a luxury item . ( I'm frugal with water not anal with it)

[PassportJoy]

Let me be more clear for you. The essence of my comment is that a water maker is expensive and it's not just the up front cost. My Catalina 300 has a sea strainer, a 50 micron, a 20 micron and a 5 micron pre filter. These pre filters all cost about $11 each when bought by the case. In addition there is a carbon block filter used during the fresh water flush every 5 days. This $20 filter lasts about 6 months. There is no formula as to how many hours of use each pre filter gets before needing to be changed. On average mine lasted about 100 hours of run time or 5200 gallons processed and 1300 gallons made. I hope this clears up the math for you.

Newhaul, I had an Islander 30 at one time and in addition to the small tankage I carried 10 gallons on deck and a 4 gallons in a sun shower bag. This lasted for a week of cruising. Good luck.

PassportJoy

[daletournier]

Originally Posted by Dirk Williams

Good morning, my boat is a smaller boat. A Hallberg RASSY 33 mistral, the origional owner appears to have been an avid coastal cruiser, and currantly has a three battery set up, charged by a very large alternator, imto a battery charger.

It's my goal to source the boat with at least 600 watts of solar, maybe 800, I don't think theirs is such a thing as to much power on a boat. I can see a wind gen on board before heading to Alaska.

And then the Honda gen set. One of the problems in trying to work thru is weight, per a question I asked last week, is how much, is to much, above and beyond for equipment in and on the boat.

Stuff, like chain and rode, anchors, water makers, solar towers, a gen set. Etc etc. how to keep the weight down yet sail,comfortably and safely.

I currantly don't have the ability to power a water maker, The boat has a 52 hp Perkins 4-108m I rebuilt within the past 90 days. ,I'd considered using this motor as the power source, but have decided that the motor compartment is just not big enough for stuff.

Solar and wind power are in my future. As for the water maker this one device is a game changer for me. The ability to make water is key for me. ,

I've read about DC power, with 800 what solar systems, after chatting with the water maker company owner, and my location " west coast" solar on off days are not realizable enough and the battery pack would be overly expensive.

The one thing I'd like to change in my plans is a Honda diesel,gen set, don't even know if Honda makes one. I'm guessing they do. I can see me eventually purchasing one specific to the boat..

I'd like to get away from gas and run everything diesel and propane.

Thank,you.

Merry Christmas.

Dirk

Im so with you on this, a diesel equivalent to a Honda. Ive literally been researching how to make one myself. Anyone that's further down the track and needs someone to invest give me a yell. A small 2 kva diesel, that's what's needed.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[daletournier]

So heres a comparison for you. On my last boat I had a 14l/hr 12v watermaker and used approx 210l-250l per week. Now I have a 140l/hr watermaker, and in the last two weeks ive averaged approximately 650l/ week! Am I any happier? Not really. If you can make more you use more. Particularly when the fairer sex suddenly believes theirs unlimited resourses!

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[aclmck]

Originally Posted by daletournier

Im so with you on this, a diesel equivalent to a Honda. Ive literally been researching how to make one myself. Anyone that's further down the track and needs someone to invest give me a yell. A small 2 kva diesel, that's what's needed.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

Yanmar 2.2KVA YDM2700 55KG runs on a single diesel tank 6-8 hrs air cooled

[Pelagic]

Originally Posted by daletournier

.
.....Am I any happier? Not really. If you can make more you use more. Particularly when the fairer sex suddenly believes theirs unlimited resourses!

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

Yes Dale, but did you ask her if she is any happier?[emoji6]