Watermaker - Experiences life expectancy of membranes

[Chotu]

Originally Posted by PirateGuy

What’s the point of high output water makers? What’s the point of passenger vehicles with 500hp engines? Or 5 bedroom/6 bathroom homes for 2 people for that matter?

Just how do you suggest men strut their junk (or women their silicone) if the world didn’t have conspicuous consumption?

I think the point is to make all your water from a short generator run. That’s why I considered a powerful, AC based water maker before getting a used Spectra.

[dougweibel]

230V water makers typically use more power, both per unit of water produced but also in general because 230V water makers typically are sized larger than 12V systems. You ask about a 60L/hr water maker. That would be a typical size for a 12V system, but typical 230V systems would be 120-160L/hr.

Flow rates for 60L/hr systems will be similar regardless of if they are 12V, 120V or 230V systems. Membranes want a flow rate that is neither too low nor too high.

[HBrew]

If the water maker is the difference between you buying a generator or not then whatever marginal benefit might be achieved by greater flow rate over the membranes will be completely offset by the cost of buying, running and maintaining a generator.
I have a dessalator 12v system and so far in 5 years I have not had to replace the membranes. Although I will be taking new ones with me when I get back to my boat next year as they have not been used for more than 2yrs now.

Hamish

[mitiempo]

Originally Posted by Dos

.......It would be a cost criteria in that case and has to do with availability in remote areas and therefore spare part reserves on board etc.

A membrane should not be carried as a spare. They have a shelf life.

[BobFord]

Eco2tec 120 litre, 7years of cruising use at a rate of 60litre per day. Powered 240vac via Generator . Replaced membranes now for first time as production was needing increased pressure and with the cost of diesel factored in, water conversion costs close to 4 cents per litre. Of course the Genny also tops up HWS and battery bank at the same time but the water making is the main reason for Genny.

[mitiempo]

Originally Posted by Dos

Hello everybody,

hope you are all well!

I am faced with the decision to equip a 12V or 230V watermaker in the approx. 60L/h range (+/-) for my Contest 41.

Best regards,
Dosheimer

Your required volume is better met with a 12 volt watermaker rather than a 230 volt one. My Spectra C380 makes 14 gallons (53 litres) per hour with 18 amp power consumption.

Why ever listen to a generator.

Membrane life has nothing to do with how the unit is powered.

[kryg]

You are on the same page as I was a year ago –

My solution NO generator! Here is my setup now running successfully for a year – and works like a charm. It hardly consumes any power from my battery’s.

I have an efficient energy saver older model Schenker Smart 60 water maker. It makes 60 litres an hour and takes 3 hours to tank 200 litres of water. My system is 12 volts, powered by two solar panels 360 watts each for = 720 watts. They are mounted over the helm on a targe. My Victron Smart Charger controller is a 150/70 manages the solar input to my house bank is 4 x 215 amp = 860 AGM battery bank. Backup I have a D 400 wind generator, which keeps the battery’s topped up at night and on very overcast days.
I'm surprised to have far more power than I need with this sent up. I run the water maker during the day once every few weeks. Also, for added safety I have added a UV Light Steriliser to kill any bugs which could possibly make it through the membrane into the product water, the UV light is installed in the product water line near the water maker out put before it goes into the tank.

Since I live on the boat while cruising, I can’t get over how effective my system is. As I run my fridge computers. And everything normally to operate the boat.

Have fun, its worth the effort.

Originally Posted by Dos

Hello everybody,

hope you are all well!

I am faced with the decision to equip a 12V or 230V watermaker in the approx. 60L/h range (+/-) for my Contest 41.

Knowing that the life expectancy of 230V systems obviously seems to be significantly better, these also usually have a power consumption that is more than twice as high. I want to try to do without a generator (have 800Wp solar and a silentwind), so that I inevitably get out of the 12V watermaker first.

Hence the question for you about your practical experience with the service life of the membranes (12V and 230V systems). Can you name a few of your experiences here? Of course, this is very dependent on the sea area (for me mainly the tropical barefoot route Atlantic + Pacific) and the frequency of use, but currently I have not been able to find any empirical values.

Would be very grateful for your hopefully numerous replies :-)

Best regards,
Dosheimer

[sailian89]

Talk to desalitor. Believe we have 12 yo membranes working fine, company said they’d be good for twenty years. We are third owner of boat, 1350 hrs on watermaker

[AndyEss]

Originally Posted by Chotu

I think the point is to make all your water from a short generator run. That’s why I considered a powerful, AC based water maker before getting a used Spectra.

I get it. One size doesn’t fit all.
To me not having yet another f$&&ing engine to take care of, maybe another fuel supply trumps the instantaneous pleasure of having a generator to give me close to unlimited, utility style power.

I’m ok without AC - which does demand a generator. I don’t suffer from life threatening respiratory issues.

Watermakers for boats with a couple, or a few more, can easily be powered by solar if you have a little patience. I hate noisy generators in an idyllic anchorage.

The planet has few such special places left. Do we really need to drag all the dreck that has taken over life everywhere we go?

[sailcrazy]

From a different perspective, we have a 230vAC powered, 30gph watermaker. We sail about 6 mo/yr, pickle it, and then put the boat on the hard during the hurricane season. It's been installed about 5 years now, still produces the same water quality it did when first installed, and works good. The admiral much prefers to cook on an electric stove, and since the boat had a genset and a AC refer system when we bought it, we just continued using the genset. We typically run the genset 1-2 times/day, for about an hour each time (cooking, pull the refer/frzr down, recharge the batts, etc. About 1day in 5-6 we'll also make water. It takes us about 1.5-2.0 hrs to refill our 180 gallon tanks....vs a cruising friend on a HR42 who had a 12v watermaker and had to run about 8 hours to refill! One factor to consider....what is the availability of parts for your machine. some are totally proprietary, and the ONLY source is the manufacturer. Others, like ours, has no proprietary parts in it, and while parts are avail from the manufacturer, they are also available in almost any chandlery. We bought ours based on that fact, and sized it to minimize the run time (1.5-2.0 hrs each 5-6 days). I'd submit there are no right-or wrong answers....it's all in what works best for you and the way you operate your boat. By the way....we're still on our first set of membranes!

[zboss]

RO membranes are cheap and I don't know why anyone cares how long they last and not just replace them on a regular basis as needed. Its great they can last 6 years if well taken care of but they are by far one of the cheapest expendables on the boat.

I have seen 40" Dows for as little as $215. Even if it only lasts two years that is a measly $9 a month. If it lasts longer than that then great... but carry a spare on a long journey and forget about it. Dow warranties new membranes in the packaging for 3 years but I bet they last a lot longer.

[Sonas]

Back to membrane replacement. We put a Bluewater Legend LX in two years ago. Strong advice then was to have one with the automatic flush. We have ours set to flush every seven days. They stated that we may never have to replace the membrane while we own the boat.

The biggest issue with membranes is letting them sit for long periods when not used (they do flush after making water). When you don't have the auto flush and/or a remote station you have to get to where it is installed (often in hard to get spaces) and trigger the back flush, and I knew I would not be diligent in that!

So I would be more concerned about maintenance than power source.

https://www.bluewaterdesalination.co...screen-control

[Tupaia]

We have a 12v Spectra, smaller than the capacity you are proposing but first membrane lasted 11 years (failed due to drying out during refit), second one is 9 years so far. The watermaker itself has had one factory rebuild carried when some parts were replaced under warranty at the same time the membrane was replaced.



Would recommend Z-Brane, exclusive to Spectra, an electrostatic probe that removes the need to pickle.

[Tudorsailor]

I have a Spectra. I have had a new pump but I am still using the original membrane from 2001!!!
I too recommend getting the Z-Ion with it

TS

[merrydolphin]

I have owned both types. My electric driven one was dependent on the generator.

I also had a Spectra. I was very happy with it and the very low electrical drain was wonderful.

The both worked. The Spectra also had the advantage on being able to work in colder waters. I never had a membrane issue with either. But I did religiously fresh water flushed the membrane after every use. I would make a little extra water and use it to flush. You know that it is pure.

Without a generator Spectra would be my choice.