Very small water-maker oder Big one for very fast refilling?

[captmikem]

A simple answer to this is to build a water maker, ( i have built a number of them, pretty simple) using a pressure washer pump with a couple of large membranes and an ac motor. Run it off a small portable genset for a couple hours every few days.
Only expensive parts are membranes and housings, but if you take care of them they will last a good long time.
M

[john61ct]

Originally Posted by captmikem

A simple answer to this is to build a water maker, ( i have built a number of them, pretty simple) using a pressure washer pump with a couple of large membranes and an ac motor. Run it off a small portable genset for a couple hours every few days.

Only expensive parts are membranes and housings, but if you take care of them they will last a good long time.

M

Links to specific HowTos ideally with detailed parts listing BoM would be greatly appreciated.

[psp2psp2]

I used to have a unit from AQUABASE which produced 90litres/hr BUT ran off 220v AC. So, of course, this was one of the reasons we had a generator.

Over the years, and across a few oceans, the time and money spent on maintaining the generator and water maker became a real pain in the ass. Especially when it came to finding spare parts in exotic locations,

So for this reason, I resolved that if I ever install another water maker, it’s going to be a small, low capacity 12v model . (I believe SPECTRA make one in Germany). I’ve seen one installed on a Bavaria 40; they’re small and not much noisier than a refrigeration compressor.

Planning to run it off solar panels might be a tad ambitious, but you should definitely factor the amperage draw from the water maker when you calculate your battery requirements.

I agree with your “water budget” of 100 liters daily; this is what we consumed with 4 people on board on long ocean passages.

https://www.amazon.com/dp/1983701122

[FlyingScot]

From another thread http://www.cruisersforum.com/forums/...ml#post2948460

I desire a smaller more efficient model, but my search has turned up nothing smaller than the Powersurvivor 40e. The 40e is about 25% more efficient than what we currently have, but not as efficient as the larger Spectra units.
40e: 150 liters per day using 96 amp hours.
260-DML-1: 150 liters in 3 hours using 120 amp hours.
Ventura 150: 150 liters in 6 hours using 54 amp hours.

[mvmojo]

I'm a fan of large capacity water makers run from the genset. Ours uses a 3 hp 220v motor and makes 33 gph (but could easily be upgraded to almost 50 gph). Run it a couple times a week for a couple hours each time and it feels like we can use as much water as we want whenever we want. Since a watermaker really should be flushed after each use, if you only make a little water at a time you end up using a fairly large percentage of your product for flushing. A larger unit reduces the percentage of waste. At shutdown, I run RO water thru the pump and over the membrane for one minute - that's between 4 & 5 gallons, under 10% of what I mad fe in 2 hours. Doing this flushes the system and keeps the membrane "healthy" but still leaves me with plenty of product water in my tanks.

Nobody I know on a boat ever said, "Gee, I've got too much water!" Years ago in the Bahamas I knew one cruiser with a large water maker who used to swap RO water for gasoline for his dinghy, 10:1 and he had plenty of takers. RO water was $0.60/gal and gasoline was $3.00/gal. His logic was that he had to run the water maker anyway for his use, might as well run it a little longer and get "free" gas for the outboard. Of course it wasn't really free when he factored in the cost of diesel & maintenance for the genset, but he still thought he was making out OK.

[Cheechako]

I think one issue is component size. Mini pumps etc are not very common. I could see that a small unit, battery powered by solar in the day only, could be a cool thing. But high quality mini pumps, membranes etc are not really out there that I know of. The Powersurvivor 40 is kind of a joke quality wise. Plastic parts etc. Maybe they are better now than they used to be I don't know.

[DMCantor]

We run our watermaker almost exclusively off solar when living aboard in the Caribbean. It is a Spectra 50 liter/hour unit with energy recovery, so we get a liter for about 0.4 amp-hours. With two of us on board, we run the watermaker for 2-3 hours every 4 days, maybe a bit more if we're doing a lot of laundry. We are careful not to waste water, but don't hesitate to use it for comfort or convenience.

[Dsanduril]

This is so much a personal thing that I don't think you can find consensus, all you can do i listen to people's opinions and find what resonates with your own lifestyle.

I dislike listening to our watermaker run. That's not what I'm out on the ocean to hear. But I like even less listening to and caring for a generator. So, we have a 25l/hr Spectra that we run from solar power. Pretty much the whole boat runs from solar, we run the ICE about once a month on average for charging purposes. We have a boat that sails well, and on most passages we never run the engine. Use it pretty much only for maneuvering and short trips across a harbor or things like that.

That's how we like things. But if I motored moderately more I'd have a large watermaker so I could make as much water as possible while power was available. And if I motored all the time I might go back to mid-size because I'd know that there's always power.

[Pizzazz]

Watermakers, like anything like to run often. To me the choice is either a small watermaker, like the 40e that runs nearly continuously assuming you can put it in a locker somewhere or a bigger watermaker that you run every couple of days. The trade off is continuous humming noise vs starting, stopping, flushing, etc. It is a personal choice.

What I like about the small watermaker (I have both a PS35 at 1.5 gph and a homemade 3.5 gph unit) is that all you need to do is flip a switch and it runs. When on passage it runs half of the time, you can’t hear it while sailing. At the Marina I just run it for 15-20 min every couple of days. At anchor I run it when away from the boat. I flush and pickle may be once a year or just replace the membrane. The larger units you cannot run as often so while great on a passage they sit unused most of the time and require maintenance which puts off people.

[Ibetitsthisway]

We belong to the sort of people who like silence.

gensets... or any sounds alike when moored - destroy the romance.
motoring under way we have no issue with.

[Mike OReilly]

I’m currently in the market for a gently used Powersurvivor 40e. I think this is the right one for us since our needs our modest (two adults, currently using 2 gallons/day, with 200 gallons of water storage), and my installation space is limited. I have surplus amps on most days, so want to run it off solar.

I think if we had it we’d likely up our water usage somewhat. But even at the dock, when water is no issue and we’re being extravagant, we still only use less than 4 gallons per day.

[a64pilot]

It’s not a matter of going small and running a lot or going large and not running it often.
It’s really a matter of are you going to try run it off of Solar? If so then output isn’t nearly as important as efficiency. If your going to try to do it on Solar, go with a Spectra, cause it’s very unlikely that you will have enough Solar to use a regular less expensive non energy recovery watermaker.

Low output doesn’t save power, it just uses less draw, but for longer times so the power required per gallon is often higher.

So if you decide for whatever reason that your not going to try to do it on Solar alone, then your going to be running something to power it, and efficiency isn’t really nearly as important as most likely you have excess power.
So that takes you to a high output one so that whatever your running to power it doesn’t have to run all day.

In my opinion it really gets down to whether or not you decide to have a generator, even a little Honda.
To do everything we wanted to do and not be the electric Nazi, I didn’t see how we could make it work in Winter without running something at least occasionally, plus I wanted the flexibility that a generator gives me, so I went the high output AC power route, that I can power with Solar and my alternator, or a generator, alternator can’t quite keep up, not with other loads going too.

[Pizzazz]

It is not so black and white, solar vs. generator. Regular watermakers use 3-4AHrs per gallon, Spectra uses 1.2AHrs per gallon but costs 2-3x more. If you use, say 10 gallons per day, you need to add 40AHrs to your energy balance, similar to your fridge at 50-60AHrs or the autopilot. How you generate this energy, solar, generator or the engine alternator is a separate issue.

I still believe the real issue is noise vs. hassle. Remember the days when one would run the engine to cool down the fridge a couple of times per day? These days are long gone. The same will happen with watermakers. They will work quietly as a fridge in the background.

[Mike OReilly]

For me, it’s no question. It’s gotta run off solar/wind. I’ve worked hard to ensure I almost never have to run the gas generator, or worse, the main diesel, just to keep the battery bank up. Nope … it’s gotta be solar/wind.

I’d love a Spectra 150. Highly efficiency. Problem is, I can’t fit it (not without major surgery), and don’t need that much production. The 9 amp draw is probably manageable on most sunny days, but that is no small draw. And lets not even talk about cost…

It’s true that the 150 is more efficient that the smaller Powersurvivor, but for me both are going to be running on free power. My house bank is usually topped up by 11 am. After that I’m throwing away amps. I could easily run a Powersurvivor (@ 4 amp-hrs) for a few hours every two to four days and keep up with our consumption. Or, I could run the 150 for one hour every three or four days. Sure, the Powersurvivor will take more overall power, but that is irrelevant to my setup since, as I say, I’m discarding amps anyway.

If I had a bigger boat, and a bigger budget, the Spectra 150 would be my choice. But I don’t. Of course if someone wants to gift me one, I wouldn’t say no .

[alctel]

Mike, I think we have a similar water usage and distaste for generators and I settled on a PS40 as well.

I have 80 gallon tanks so even if I only make a gallon or two a day, that's only an extra 5-10 amps usage a day, which should keep me topped up. And even if I am using more than I am putting back, it's not going to be by much and with 80 gallons that will last a long time (or at least till the next rain shower - I have a rain catcher too)

For me the small size is a big plus and I don't need as much water as you get with the bigger ones