Realistic sized desalinator (water-maker)

[coopec43]

I am busy installing the water tanks right now. I had planned on three tanks down inside the keel plus four "wing-tanks" but have now discarded the wing tanks because I realize I need to increase the size of the house battery bank to 4 X 135 Ah (and I need the room). The three remaining tanks will have a capacity of around 105 US gallons (390 L).

I've looked for threads on desalinators for yachts but they are all technical. My questions are:

• How many liters per day (or per hour) is a realistic size?
• Has anyone had feed-back on the kits available for people who prefer to DIY

https://www.ebay.com.au/itm/Boat-des...frcectupt=true


Clive

[Zai]

I have a 30 liter per hour watermaker and while it is "enough" in my opinion it would be nice to have more capacity.
It would be nice to have a larger membrane with two supply pumps, of which one or both pump could be run depending on circumstances.

[44'cruisingcat]

It really depends on how much water you need.... with two of us aboard we use about 40 litres per day, so our 40 litre/hour watermaker is fine for us. Run it for 2 hours every other day.

Also, the set up of your boat... how much solar, or do you need to run a diesel to charge batteries. If so then a large capacity engine driven unit might be a better match. If you run a genset, a 240 or 100 volt unit. If solar, then a 12 volt unit.

[coopec43]

Originally Posted by Zai

I have a 30 liter per hour watermaker and while it is "enough" in my opinion it would be nice to have more capacity.
It would be nice to have a larger membrane with two supply pumps, of which one or both pump could be run depending on circumstances.

Would that unit run off the motor or can they realistically be battery powered? (this is all new to me)


Clive

[coopec43]

DIY – The World's Cheapest Watermaker.

by Ted Nobbs on 9 May 2007

"For long range cruising, or even a three week holiday, we think a watermaker is an essential item on a boat. The commercial variety range in price from approximately US$3,500 to US$11,000 for a water production rate of 40 -140 litres an hour.

Bob tells me that this design has been passed around the long range cruising community for the past few years. It produces 100 litres per hour, for, with diligent buying, a cost of approximately US$2,000."

www.sail-world.com/33568


Clive

[Sailmonkey]

Realistic is for you to decide.

How much water do you use per day?

How will you power it?

[Jeanneau 45.2]

Higher capacity requires 120V power. I have one and produce 24 gals per hr. We use a lot of water, so I run every other day for 2 hours to keep up with needs. Water is like money ... more you have the more you find ways to use it.

[Cheechako]

Mine were engine powered, assembled from kit or a used 120v watermaker. Something like 24 gal per hour max. manual controls.
Filter>Cat pump> Pressure relief valve> Needle valve to adjust pressure>Membrane(s)>water tank.

[sailcrazy]

After you determine how much water you need/day, then you need to decide how often (1/day, 1/2days. 1/3days, 1/4days), and how long each time you run it. We have friends who run theirs every day for 8 hours! With the 2 of us onboard, we run our 30gph machine for approx.2 hours every 3-4 days.....it really is... all up to you. But IF you have a genset, and you expect to run it every (??) days to recharge the batts, etc....then you could also make water at that same interval. Or, like my friend, you could run it off the house bank every day for (??) hrs. It really does depend on how you chose to manage it!

[PEACEMAKER 455]

I have a CJD WATERMAKER NZ made 12 volt 16 amp 60 liter per hr very quiet I have the auto flush model water is now no problem

[Cpt Mark]

As an alternative you might check this guy out. His units start at $1600. Produces 21 GPH. Essentially the same as the DIY drawing above except he's sourced all the pieces for you.

https://seawaterpro.com

How much water do you need? That's a personal question. Live on your boat, don't use shore water, marina bathroom or shower. Live as you normally do and keep track of how often you fill your water tank(s). I'm in the PNW and going into the tropics will need more water for hydration and rinsing dive equipment so am planning for a larger system.

[DMCantor]

We have a 12.5 gal/hour Spectra, and it is plenty big enough for the two of us. Very energy efficient, about 1.5 amp/hr per gallon. We generally run it every 4th or 5th day for 3 hours. We have enough solar and wind to power the unit most of the time.

In general I think simpler is better, and the engine-driven units seem complicated to me. The Clark pump on our Spectra isn't exactly simple, but the energy savings make it more than worth it.

If you have a generator on board anyway, then I would certainly go with an AC powered unit. You can pick your capacity to match your run time to the time you need for battery charging.

[Ivansgarage]

Try this guy has a very very good reputation....
He is in Tucson Arizona

http://sunpurewatermakers.com/

[GeneM]

Originally Posted by coopec43

DIY – The World's Cheapest Watermaker.

by Ted Nobbs on 9 May 2007

"For long range cruising, or even a three week holiday, we think a watermaker is an essential item on a boat. The commercial variety range in price from approximately US$3,500 to US$11,000 for a water production rate of 40 -140 litres an hour.

Bob tells me that this design has been passed around the long range cruising community for the past few years. It produces 100 litres per hour, for, with diligent buying, a cost of approximately US$2,000."

www.sail-world.com/33568


Clive

Are you at all concerned about the PH of drinking water? I hear it's quite acidic unless treated.

[sailorboy1]

Originally Posted by GeneM

Are you at all concerned about the PH of drinking water? I hear it's quite acidic unless treated.

Was typing a response, but decided you need to do the basic lookup