12 volt watermakers, which one?

[sy_gilana]

Interesting.


It looks like the Pure-Water and the Eco-Sistems machines are almost identical, except for the labelling.

[newhaul]

Originally Posted by sy_gilana

Interesting.


It looks like the Pure-Water and the Eco-Sistems machines are almost identical, except for the labelling.

they are the same just like a Chevy and a tmr pickup are the same just slightly different packaging.

[a64pilot]

Ref the minerals thing, do not confuse “real” RO units that take fresh water and purify it to an extreme for Hemo Dialsysis and other uses that require extremely pure water.
Yes those will de-mineralized water to a point to where it’s not likely healthy to drink, but our sea water to drinking water RO systems are a far cry from those, a lot has to do with how pure the water is to start with.
My Father put himself on Hemo Dialysis at home for years, his RO output measured 0 with a tds meter, my drinking water output measures about 100 or so, a little higher in warm water, much lower in cold. If you want to buy a mineral filter cartridge, go ahead it won’t hurt, or add whatever mineral you want, maybe be sure to not add too much though, you can’t taste salt in water that is too salty to be healthy to drink, that is why we really should test our RO output, cause you can’t rely on taste.
If I were adding salt to water, I’d be sure to test it after I did to make sure I was well below 300, tds meters are as cheap as flashlights, no reason or not have one and test often

[newhaul]

Originally Posted by newhaul

they are the same just like a Chevy and a tmr pickup are the same just slightly different packaging.

hate autocorrect Chevy and gmc pickups

[ssmoot]

Originally Posted by CarinaPDX

Today the components to make an RO unit are readily available, and there is no need to pay those ridiculous prices. My friends on 2 boats heading out to go cruising were both looking into building their own systems - until they found this: https://seawaterpro.com/ Why anyone would consider paying $5k when they could get an RO for $1.5K is beyond me. But of course they aren't spending a lot of money on advertising so there is a reason no one has mentioned them yet. Take a close look at them.

Greg

I couldn't find watts-per-gallon or dB rating on their site. Do you happen to have that information? I'm curious how it compares to the Spectra units of around 15watts/gal and 54dB operation.

[sy_gilana]

I have never understood the watts per gallon metric. In my opinion its not a measure of anything. Please correct me if I am wrong.

A watt is a measure of power, that is, instantaneous power, analogous to speed.
Watts per gallon, umm thats like saying I can do 100mph on a gallon.

What is more important is the energy consumption per gallon.

So if the machine can do say 10 gallons per hour and it draws 15 watts per gallon, do you multiply that and say its 150 watts per hour, at 12 v it would be 12.5 Ah per Gallon.

Is that correct ?

15 Watts is 1.25 Amperes, is it conceivable that is true? Thats less than a nav light.

I would love someone who has a "15watt per gallon" machine to actually measure the amperage while it is in production.

[newhaul]

Originally Posted by sy_gilana

I have never understood the watts per gallon metric. In my opinion its not a measure of anything. Please correct me if I am wrong.

A watt is a measure of power, that is, instantaneous power, analogous to speed.
Watts per gallon, umm thats like saying I can do 100mph on a gallon.

What is more important is the energy consumption per gallon.

So if the machine can do say 10 gallons per hour and it draws 15 watts per gallon, do you multiply that and say its 150 watts per hour, at 12 v it would be 12.5 Ah per Gallon.

Is that correct ?

15 Watts is 1.25 Amperes, is it conceivable that is true? Thats less than a nav light.

I would love someone who has a "15watt per gallon" machine to actually measure the amperage while it is in production.

The correct way to write that would be wh watts per hour. My watermaker is 4 amp draw so 4ah and produces 1.5 gallons per hour .so that would be 4 amps x 15 watts =60 watts per hour ÷1.5=40 wh per gallon.

Does that explain it better?

[a64pilot]

It’s normally quoted as AH per gl or Liter.
I wish we would drop the AH thing, cause 1 AH at 12V is considerable less power than 1 AH at 14 V and use watt/ hour.
But that’s not going to happen, so we are stuck with AH which isn’t a constant unfortunately.

It is very relevant though, cause one machine may pull 15 amps, yet only make 5 gls in an hour, another may make 15 gallons an hour and pull 15 amps.

However as has been pointed out, power consumption per volume of water made is really only relevant to a DC machine, cause of the very limited power available.
An AC machine is assumed to be run off of a generator and there how many gallons per hour is more relevant.

It’s not uncommon for an AC machine to make more water an hour than some DC machines will in a Solar day. Solar day being the time your panels are making significant power, about 5 ish hours a day on average.

So in picking whether AC or DC you need to consider how much water would you like to have maybe more than how much do you need, as well as cost of course, cause there are high output, efficient DC ones, but wow are they expensive

[john61ct]

>> power consumption per volume of water made is really only relevant to a machine **intended to run off solar+batteries** cause of the very limited power available

FIFY

[LeaseOnLife]

Originally Posted by newhaul

The correct way to write that would be wh watts per hour. My watermaker is 4 amp draw so 4ah and produces 1.5 gallons per hour .so that would be 4 amps x 15 watts =60 watts per hour ÷1.5=40 wh per gallon.

Does that explain it better?

To expand on newhaul's explanation.

I really like the Wh better than Ah, since some boats run on 24V vs 12V

For my Spectra Cape Horn the specs calculates to 15.4 Wh per gallon. With this, it makes 14 gal/hour. Multiply both, you get 216 Watts power consumption, at 12 V that is 18A.

I did a quick check/calc for the other DC watermakers with energy recover or energy transfer devices.

PureWater Whisper 60: 16.6Wh/gallon
Spectra Cape Horn: 15.4Wh/gallon
Schenker Smart 60: 15.14Wh/gallon
Aquabase ESB601: 16.6Wh/gallon

Above values are all very close to each other, while watermakers without the energy recover or energy transfer devices need about double the energy for each gallon of water.

[newhaul]

Originally Posted by newhaul

The correct way to write that would be wh watts per hour. My watermaker is 4 amp draw so 4ah and produces 1.5 gallons per hour .so that would be 4 amps x 15 watts =60 watts per hour ÷1.5=40 wh per gallon.

Does that explain it better?

sounded way off but I checked and my powersurvivor35 manual says 4 amp / 50 watt draw for 1.4gph. So the per gallon power consumption is 37 wh

[Pete7]

Originally Posted by Franziska

So, are there any reasonable priced and still reliable DC desalinators with an energy recovery similar to the Spectra around for less money?

Franziska, I think your first problem is location. Based in NW Europe we are blessed with lots of free water everywhere. Indeed I would be pushed to name somewhere you can't drink the tap water in Europe. We are currently sat in Weymouth, the tap on the harbour wall is 10 ft away which I topped up the tank with this morning. No filters, straight into the tank and from there into the kettle to make tea or drink from the tap. Therefore the availability of new or used water makers is few and far between because there just isn't a need for a water maker in N Europe and even the med is questionable.

However, since you have a genny then Rich Cohens approach for 240v simple water makers seems sensible. However, the import duty and VAT will be a problem unless you fancy a trip to the Channel Islands perhaps. On a similar theme but UK based are these. They were being advertised on e bay during the winter for £2200 for a basic mains 240v watermaker.

NEW - - Sailfish Marine - Watermakers, Marine Generators, Solar Panels and more..

[SV THIRD DAY]

Originally Posted by newhaul

The correct way to write that would be wh watts per hour. My watermaker is 4 amp draw so 4ah and produces 1.5 gallons per hour .so that would be 4 amps x 15 watts =60 watts per hour ÷1.5=40 wh per gallon.

Does that explain it better?

An interesting comparison....

Our 33GPH 120v AC water maker uses 1100W (sells for $5250)
www.cruiserowaterandpower.com/uploads/sm30.pdf

So that is 1100W/33GPH = 33 Watt Hours per Gallon, or more energy efficient than the 37WH powersurvivor35....
But of courses an energy recovery 12/24v water makers beats the Piston Pump energy Hog hands down:
PureWater Whisper 60: 16.6Wh/gallon
Spectra Cape Horn: 15.4Wh/gallon
Schenker Smart 60: 15.14Wh/gallon
Aquabase ESB601: 16.6Wh/gallon.

BUT of course you have to have a generator for an AC 120/220v water maker to make sense on your boat. But once you do, rather than draining power from the battery bank during a water maker run, you are topping off the batteries. It's a completely different mindset.

So which way is the "right way"....easy....whatever works for YOU. And there is the danger of advice.....unless you know the mindset and what makes sense to you and the person giving you advice...well that is how people wind up with the "wrong water maker".

[newhaul]

Originally Posted by SV THIRD DAY

An interesting comparison....

Our 33GPH 120v AC water maker uses 1100W (sells for $5250)
www.cruiserowaterandpower.com/uploads/sm30.pdf

So that is 1100W/33GPH = 33 Watt Hours per Gallon, or more energy efficient than the 37WH powersurvivor35....
But of courses an energy recovery 12/24v water makers beats the Piston Pump energy Hog hands down:
PureWater Whisper 60: 16.6Wh/gallon
Spectra Cape Horn: 15.4Wh/gallon
Schenker Smart 60: 15.14Wh/gallon
Aquabase ESB601: 16.6Wh/gallon.

BUT of course you have to have a generator for an AC 120/220v water maker to make sense on your boat. But once you do, rather than draining power from the battery bank during a water maker run, you are topping off the batteries. It's a completely different mindset.

So which way is the "right way"....easy....whatever works for YOU. And there is the danger of advice.....unless you know the mindset and what makes sense to you and the person giving you advice...well that is how people wind up with the "wrong water maker".

interesting point of view since I have 400w solar 400w wind and a diesel generator and a 65 amp alternator feeding what will be 200ah Lfp bank . And I'm running a 12v watermaker.

[Franziska]

@Pete7

Thanks, we drink the tap water all the time for now. But, we are prepping slowly for the big departure to places where this will not be possible.

Apart from that we try to avoid marinas where we can. Anchor and mooring is, much more our thing.
Thats including choosing equipment and deciding budget wise where we set our preferences.
So all the info here is mightily interesting!!

Will not purchase before final refit though.
Funny enough I spent a lot of time on the channel islands 2016...