Water maker comps

[john61ct]

Oopsie

[travellerw]

Originally Posted by robert sailor

These types of things are not cheap in Europe...No body sells these types of products cheaper than in the States. Boats yes, but not watermakers

How about these guys... Sold in Europe and 1/2 the price of the one listed by ROM.. Just slightly higher (when converted) than I paid in the USA.

https://www.thewetworks.co.uk/produc...n-water-makers

[robert sailor]

Originally Posted by john61ct

And if it were that easy to just slot in a DC version of that motor, I bet Rich would be offering that option, rather than turning business away.

He does also sell the ones that power directly off your own motor's PTO too, but reckons they're not worth the headaches.

It's not so much the motor, it's the Clark pump that makes the Spectra so efficient. It basically uses a modified 12 volt fresh water pump similar to what you use for your water system and that is fed under low pressure to the Clark pump that increases the pressure to the membrain, it's a very ingenious method but of course doesn't come cheap. DC motors use their additional power to drive a high pressure pump and while it's a cheap system it is anything but efficient so you pay for efficiency or you use a lot more power and burn diesel or gas to run the watermaker.

[robert sailor]

Originally Posted by travellerw

How about these guys... Sold in Europe and 1/2 the price of the one listed by ROM.. Just slightly higher (when converted) than I paid in the USA.

https://www.thewetworks.co.uk/produc...n-water-makers

Should have had a bit of tongue in cheek as your now dealing with the Australian and British currencies and trade arrangements. Typically costs are higher in Britain for almost anything to do with yachts. If you can buy an Australian product cheaper in the USA then your still good to go. I also expect the dealers there are getting a preferred price as your market is very large. You guys are 10 times bigger than us and we are a 3rd bigger than Australia so you are just able to do better on most products...well until you start throwing on tariffs and start trade wars, then things will change

[rom]

Originally Posted by DotDun

You just confirmed what I thought! Your WM was 2 times the cost of mine!

30 GPH Marine Water Maker by Cruise RO Water & Power

Yeah I knew about those guys, looks good. It's nice to have more & more choice on the market, prices are getting lower, and the CRO makes a very good alternative to the Dessalator AC !

But then, aren't there any other manufacturer proposing a similar WM system with a DC motor ?

[travellerw]

Originally Posted by robert sailor

Should have had a bit of tongue in cheek as your now dealing with the Australian and British currencies and trade arrangements. Typically costs are higher in Britain for almost anything to do with yachts. If you can buy an Australian product cheaper in the USA then your still good to go. I also expect the dealers there are getting a preferred price as your market is very large. You guys are 10 times bigger than us and we are a 3rd bigger than Australia so you are just able to do better on most products...well until you start throwing on tariffs and start trade wars, then things will change

Nope.. Unfortunately as a Canadian we get screwed on all fronts.

[kenbo]

Originally Posted by rom

Yeah I knew about those guys, looks good. It's nice to have more & more choice on the market, prices are getting lower, and the CRO makes a very good alternative to the Dessalator AC !

But then, aren't there any other manufacturer proposing a similar WM system with a DC motor ?

Yes there are several, but the physics of watermaking require power, lots of power if you want your system to operate properly.

Unless it a proprietary membrane, all off the shelf membranes require a minimum of 3/4 hp to drive enough flow at the required pressure. 1 hp is better especially for the 40" membranes.

A 12vdc 1 hp motor draws 90A when running, 3/4 hp about 75A. Unless you have LiFePO4 batteries that draw will really put a strain on lead acid battery banks or you would need a significant solar array. Remember, all battery bank ratings are based on a 20 hour draw down. Your bank size "shrinks" quite a bit when you hit with 90A loads.

Some 12vdc WM manufacturers use lower hp motors to sell their product but the membranes will suffer and performance will drop precipitously over time since the will the pressure is there the flow is not.

[robert sailor]

Even the dc systems that are out there draw lots of power and don't make that much power. The only dc system that is able to sip amps and produce water in high volume is Spectra. In my mind there are only 2 choices, Spectra for those that want to operate on DC power and a bunch of others that operate on AC run by a portable gas genset or a built in diesel genset. Watermakers and particularly the membrane likes to be run often. Check out the resale value of a used Spectra if you want to see a product that currently holds its value. I see the logic going either direction but personally i dont like to be dependant on a genset to get water.

[kenbo]

Originally Posted by robert sailor

Even the dc systems that are out there draw lots of power and don't make that much power. The only dc system that is able to sip amps and produce water in high volume is Spectra. In my mind there are only 2 choices, Spectra for those that want to operate on DC power and a bunch of others that operate on AC run by a portable gas genset or a built in diesel genset. Watermakers and particularly the membrane likes to be run often. Check out the resale value of a used Spectra if you want to see a product that currently holds its value. I see the logic going either direction but personally i dont like to be dependant on a genset to get water.

I agree that Spectra is by far the best 12vdc WM but the price of admission is high.

Cruise RO is very efficient for an ac model 30g/110l per hour for 9.3A @ 110vac.

[rom]

Originally Posted by kenbo

Yes there are several

Can you name some ?

Originally Posted by kenbo

Unless it a proprietary membrane, all off the shelf membranes require a minimum of 3/4 hp to drive enough flow at the required pressure. 1 hp is better especially for the 40" membranes.

interesting ! I will check which membranes my WM has .

Originally Posted by kenbo

A 12vdc 1 hp motor draws 90A when running, 3/4 hp about 75A. Unless you have LiFePO4 batteries that draw will really put a strain on lead acid battery banks or you would need a significant solar array. Remember, all battery bank ratings are based on a 20 hour draw down. Your bank size "shrinks" quite a bit when you hit with 90A loads.

Considering 1hp is about 750W, then that would be about 60A@12V. Closer to mine BTW which sucks about 50A@12V. Where do you get your 90A from ?
Peukert factor, of course you're making a good point but it has to be put in perspective with how much Ah you have. e.g. my WM draws 50A which is not that much considering I have 1000Ah (Gel).

Originally Posted by kenbo

Some 12vdc WM manufacturers use lower hp motors to sell their product but the membranes will suffer and performance will drop precipitously over time since the will the pressure is there the flow is not.

I have to say I am bit skeptical there, can you name some ?

[rom]

Originally Posted by kenbo

I agree that Spectra is by far the best 12vdc WM but the price of admission is high.

Cruise RO is very efficient for an ac model 30g/110l per hour for 9.3A @ 110vac.

That I don't understand. My simple (yet expensive) WM draws about 600W for 100l/h (26.5gph) and the CRO draws about 1000W for 113l/h (30gph). How can you call that efficient ?

[Paul L]

Originally Posted by DotDun

The math needs to include the upfront cost also. AFAIK, high output 12v WMs are ~2 times the cost of high output AC units.

A CRO 20gph unit is usd$4400 plus 1,000 for a Honda genset = 5,400. AC only
A Spectra Cape Horn 15gph is $6,700. DC 8 or 15 amps, depending on mode.

That really isn't that big a difference in cost. The other factors are more important.

[kenbo]

Originally Posted by rom

Can you name some ?

Aquamarine, Echotec and Electromaxx used to but are now reps for Schenker

interesting ! I will check which membranes my WM has .

Considering 1hp is about 750W, then that would be about 60A@12V. Closer to mine BTW which sucks about 50A@12V. Where do you get your 90A from ?

From the motor manufactures that supply the watermarkers. Leeson is the most efficient, affordable motor at this time and the 1hp draws 80A all the others draw 90A.

Peukert factor, of course you're making a good point but it has to be put in perspective with how much Ah you have. e.g. my WM draws 50A which is not that much considering I have 1000Ah (Gel).

Your WM most likely has a 1/2hp motor and a smaller membrane.

I have to say I am bit skeptical there, can you name some ?

Yes, Echotec and Electromaxx before they stopped making their own WMs.
Here's Echotec's 12vdc info page. Watermakers / Desalinators for Yachts - 12 V DC / 24 V DC

You can see they are supplying 40" membranes with as small 1/4hp motors! Inferred from the amperage draw. They can achieve the required pressure but the flow across that 40" membrane is well below Dow's required minimum.

[kenbo]

Originally Posted by rom

That I don't understand. My simple (yet expensive) WM draws about 600W for 100l/h (26.5gph) and the CRO draws about 1000W for 113l/h (30gph). How can you call that efficient ?

I believe I said an efficient ac model.

[kenbo]

Originally Posted by rom

That I don't understand. My simple (yet expensive) WM draws about 600W for 100l/h (26.5gph) and the CRO draws about 1000W for 113l/h (30gph). How can you call that efficient ?

Unless you have some form of energy recovery in your WM or your 12vdc motor was stolen from the space program, I have to disagree that 100l/h can be produced from 600w. Have you captured your product water and measured it? Or is that the manufacturer's claimed output. About the best a 1/2hp motor can produce is about 50-55l/h. That's simply the physics of watermaking.