Spectra Water Makers Advice Please

[BigBeakie]

SV Third Day,

I read with great interest last night your contribution to another previous thread in which you discussed your product vs Ecotec. That thread was very educational & helped alot in understanding how to choose the right watermaker for our situation, and the issues involved. Big thanks for that

Even after all that great information there is still one aspect I'm not clear about and that is looking at the difference between an AC high volume unit driven by a DC motor (eg the ECOtec DC range), and a DC unit where you highly recommend the Spectra because of the difference in amps to get equivalent water output, because they use the energy recovery Clarke pump technology.

To summarize, if I've got it right, you & others say that if you try and run a non Clarke pump type unit on DC, it is not possible to put enough amps back in the battery after the watermaking session from renewable sources like wind and solar, given the typical equipment most cruisers have on their boat.

The key point I think colemj made was DC watermakers need full voltage 13.8 V to run properly, so if running off battery, the DC watermaker would drain the battery down below 13.8 V and so there is a problem. Is this correct? Can you, or Tellie, explain what happens to the water production in this scenario? Eg does the water production slow down? Does the system pressure suffer? What happens?

I must be dumb, but I don't understand what the issue is with replacing the amps from solar, on cats. Wouldn't you just size the solar installation accordingly to cope? I hear what colemj is saying, that it just doesn't work from an energy balance issue, but a voice in my head says "Why not???"

Thanks for your patience from a newbie

[Snowpetrel]

Originally Posted by noelex 77

The only thing that seems to give any problems is automated electronic systems, so stick to one of the manual control models for best reliability. The Cape Horn looks great.

+1. Ive had both the salinity sensor fail and a Clark pump sensor go. In both cases switching to the manual override and operating them by taste worked fine.

At least the spectra unit had that option easily availible. When it worked the automatics where nice, but the manual operation would have been easy enough if it had been set up with that in mind. Rather than having to crawl into the Engine room to taste and then swap it into the tanks.

Another boat had a very old membrane fail. Not much we could do about that unfortunately.

[SV THIRD DAY]

Originally Posted by BigBeakie

I must be dumb, but I don't understand what the issue is with replacing the amps from solar, on cats. Wouldn't you just size the solar installation accordingly to cope? I hear what colemj is saying, that it just doesn't work from an energy balance issue, but a voice in my head says "Why not???"

Thanks for your patience from a newbie[IMG]file:///C:\Users\User\AppData\Local\Temp\msohtmlclip1\01\c lip_image002.gif[/IMG]

Experience vs. Calculation...that is the issue at heart here.
I have a 1380W solar system and would still not choose a 19.8A draw over a 9A.



Forget the getting down in the weeds of battery voltage vs output effect on DC water makers. Sure it matters a bit, but don’t miss the forest for the trees by focusing on the smaller issues while ignoring the elephant in the room Your Batteries!



We have been focusing on an energy recovery vs non-energy recovery question, but I think the understanding comes by pulling back to the 40,000ft view. It's not as much of a water maker question as it is a ballance of boat power BATTERY question with some assumptions, like you will have Lead Acid batteries and not some big new Lithium Iron Phosphate battery bank.

For a normal cruising boat with the normal battery bank of Lead Acid Batteries, running the 19.8A load for the time needed to keep up with your water demands will be too much for most solar/wind to deal with. Oh on a spreadsheet you will calculate 19.8A * 3Hrs/day = 59.4AH and you will think, easy, I can put that back in with my solar panels. Then you will get out cruising and realize that those 59.4A are kicking your rear end, dragging your voltage down and just making it too hard to keep your battery bank healthy. So you will then make water by running your engine or generator to help keep your batteries from taking the hit.



It’s not just the Amp hours that matter by the instant Amps draw. Pulling 19.8A out of a battery bank is a LOT harder on the bank than pulling out 9A. We spent lots of time cruising Mexico and I always knew when folks were running their 12v water makers at anchor because they were running a generator or worse their main engine! So if I can make water for 9A vs 19.8A it’s just a no brainer for your battery bank. You will want that extra power to go into battery health and refrigeration rather than powering your water maker.

Remember...this in terms of water makers: DC, AC, Engine Driven, Etc.
The only REAL difference once you strip away the fancy electronic controls and display panels is the high pressure pump. Take a spectra or Echotec, or Cruise RO water maker and set them side by side. Same technology with the difference being: How do you get sea water up to 800PSI to drive a portion of the fresh water through the membrane.

[BigBeakie]

Hey, thanks Rich. You have a knack for clear communication. The straight talk is much appreciated. You should write a "Watermakers for Dummies" book. I'm only half joking.

So basically you are saying the consideration is NOT any operational impact on the 12V pump, but the energy management and battery bank consideration ie Gel or LA versus LiFePO4 battery characteristics.

I am CONSIDERING an electric-hybrid (ie diesel genset) propulsion cat and running house amenities as electric as I can, so we are planning not only a significant solar installation but also LiFePO4 as a necessity.

The Diesel genset is for extended motoring beyond the capacity of the batteries, and for other adverse scenarios like long cloudy periods at anchor. But we would like solar to be the main fuel source at anchor, complemented by high output regeneration while at sail with the electric motors and/or Watt & Sea hydrogenerator.

So to cut to the chase, it seems for my situation with a new build project with lots of new efficient solar (1 to 2 kW) & big LiFePO4 battery bank(s), then we could consider using one of the inefficient 12V watermakers and still get away with it.

I accept that others may not have the adequate renewable input capability or still be using lead batteries with 50% DOD and slower recharging limitations, in which case your recommendations on not using a more inefficient 12V watermaker makes alot of sense.

Have I got that right?

[SV THIRD DAY]

I think you nailed it.

LiFePO4 batteries and the type of boat system you are setting up make the normal "energy recovery" vs "energy hog" battery issue mute in my opinion. In your case I would then look towards durability and price. As much as I like Spectra,! if energy efficiency isn't the main issue then I like the EchoTec piston pump 12v unit. Heck at that point....run a 30GPH water maker through a 2000W inverter 2-3 times a week....who do I know that has something along those lines...

We have a client with a 800AH LiFePO4 battery bank on a Seawind Cat in Mexico running our 30GHP unit from his battery bank. I'll actually be driving down to visit him this weekend for a look-see and Taco Cart run, so I'll snap a few photos for you.

[roetter]

We have a Newport MKII 400 that was installed by Tellie. Thanks Tellie, great job, and always there to answer my questions on the phone.

We have 1800W solar on 1400Ah 12V LiFePo.

We use at least 3-times the amount of water than we would have thought. Tellie installed for us a diverter that we run into a 20l drinking water canister, the rest gos into the tanks for shower, dishes and laundry. We run the watermaker 15-20 hours per week when we are 4 persons on board.

In the tropics the boat picks up huge amounts of salt and the time to the next rain can be far away. We already spend way too much time keeping ahead of the rust on the not so "stainless". So we wash the salt off at least twice a week with fresh watermaker water.

We never go to a marina.

[BigBeakie]

Rich that would be most appreciated

Are there some efficiency considerations for 12V "inefficient" pump directly off battery bank versus AC system off inverter? Wouldn't it make more sense to run 12V directly rather than inverter. We will have inverter obviously for appliances etc, so can go either way. I guess we would get more product volume in shorter time with higher output AC system?

In terms of supplying a customer in Australia, maybe we should have a chat on Skype sometime, eh? I will be away all weekend but we could PM each other with Skype addresses and catch up next week, maybe?

[wildcat35]

does any one know witch surflo supply pump the spectra ventura 150 uses.

[SV THIRD DAY]

Originally Posted by roetter

We use at least 3-times the amount of water than we would have thought.....
We already spend way too much time keeping ahead of the rust on the not so "stainless". So we wash the salt off at least twice a week with fresh watermaker water.
We never go to a marina.

I’ve found Roetter’s experience to be dead on…once you have a water maker…you will always find a way to use it!

Originally Posted by BigBeakie

Are there some efficiency considerations for 12V "inefficient"[IMG]file:///C:\Users\User\AppData\Local\Temp\msohtmlclip1\01\c lip_image001.gif[/IMG] pump directly off battery bank versus AC system off inverter? Wouldn't it make more sense to run 12V directly rather than inverter

Just swap out the 1.0Hp 120v AC motor with a 1.0Hp 12v (or 24v) DC motor (80A at 12v) and sha-zam...33GPH 2-3 times a week should keep you with plenty of fresh water, showers, deck and gear rinse downs and most importantly the Admiral Happy!

We ship 3-4 water makers to Australia a month…DHL and 7 Days…the world isn’t as big as it once was.

[Tellie]

Originally Posted by BigBeakie

SV Third Day,

I read with great interest last night your contribution to another previous thread in which you discussed your product vs Ecotec. That thread was very educational & helped alot in understanding how to choose the right watermaker for our situation, and the issues involved. Big thanks for that

Even after all that great information there is still one aspect I'm not clear about and that is looking at the difference between an AC high volume unit driven by a DC motor (eg the ECOtec DC range), and a DC unit where you highly recommend the Spectra because of the difference in amps to get equivalent water output, because they use the energy recovery Clarke pump technology.

To summarize, if I've got it right, you & others say that if you try and run a non Clarke pump type unit on DC, it is not possible to put enough amps back in the battery after the watermaking session from renewable sources like wind and solar, given the typical equipment most cruisers have on their boat.

The key point I think colemj made was DC watermakers need full voltage 13.8 V to run properly, so if running off battery, the DC watermaker would drain the battery down below 13.8 V and so there is a problem. Is this correct? Can you, or Tellie, explain what happens to the water production in this scenario? Eg does the water production slow down? Does the system pressure suffer? What happens?

I must be dumb, but I don't understand what the issue is with replacing the amps from solar, on cats. Wouldn't you just size the solar installation accordingly to cope? I hear what colemj is saying, that it just doesn't work from an energy balance issue, but a voice in my head says "Why not???"

Thanks for your patience from a newbie

Just to jump in again. Not sure where the 13.8V figure quite comes from. A Spectra will produce it's rated out put down to 12.5 volts. You also need to understand there are several models of units and comparing them can be apples and oranges. Driving a high pressure plunger type pump with a 12V motor is highly inefficient. A plunger pump depends on rpms to produce both it's flow and pressure. Sure it can be done but it makes no sense because you do have to calculate your energy draw compared to how you intend to put those amps back into your battery bank. Putting a certain number of amps back into your battery bank has nothing to do with your watermaker or any electrical draining system on your boat. It is based on what you have on the boat that is capable of charging your batteries. What I find is that most people fail to create an honest daily amp budget which is extremely important on a boat that relys on it's house battery bank to do most of the electrical work needed on a daily basis. I walk on dozens of boats every week of all makes, models, and sizes. One of the first questions I ask is "Have you figured out your daily amp usage?". Eight out of ten times the answer is no. This is where a lot of cruisers, especially new ones get into trouble as they start adding all the electrical toys they want. Usually with these folks I won't even begin discussing what brand or size watermaker they might need until they have a better understanding of their electrical system. AC systems are great, I sell a lot of them,..to the right people. I also sell a lot of DC systems,..to the right people. If it's just a simple matter of making as much water as you can in the shortest period of time on a small generator I can easily do that with a Spectra better than anyone else. With a small generator making 115 Volts using only 7.5 amps I can make 75 gallons per hour. Make it 220Volts and I can get you 120 gallons per hour with only 5 amps per hour. But that is ridiculous for smaller cruisers with 100-150 gallons of fresh water tankage. You could also buy what I consider a toy watermaker that will make about one gallon per hour and use more energy that a 14 gallon an hour Spectra, but you can save a thousand dollars or so by going that route, you won't be happy but it can be done as well. Choosing the right watermaker is a balance between your wants, needs, and your boats real capabilities. I call it the Goldilocks effect. What is right for your dock buddy may not be right for you. Taking advice from someone who has only had one or two watermakers, and has known some people with them is usually not a very good idea no matter how well meaning they are. Cruisers come in all sizes, needs and demands. There are those that will demand only the basics and the full hands on experience and there are those that only want to push a button and make water. You really need to talk to people in the industry who deal with these things for a living, on the phone or in person, or better yet ask them come out to your boat. There are some really good people out there and for the most part we know each other. We also know who you should stay far away from.

[Tellie]

Originally Posted by wildcat35

does any one know witch surflo supply pump the spectra ventura 150 uses.

These are a Spectra pump built by Shurflo for Spectra to meet the demands required of it. If you are in the South Florida area give me a shout and we can discuss it.

[Tellie]

Originally Posted by roetter

We have a Newport MKII 400 that was installed by Tellie. Thanks Tellie, great job, and always there to answer my questions on the phone.

We have 1800W solar on 1400Ah 12V LiFePo.

We use at least 3-times the amount of water than we would have thought. Tellie installed for us a diverter that we run into a 20l drinking water canister, the rest gos into the tanks for shower, dishes and laundry. We run the watermaker 15-20 hours per week when we are 4 persons on board.

In the tropics the boat picks up huge amounts of salt and the time to the next rain can be far away. We already spend way too much time keeping ahead of the rust on the not so "stainless". So we wash the salt off at least twice a week with fresh watermaker water.

We never go to a marina.

Hi Rolf,

Great to hear from you. Hope your travels are going well.
Tell Silka that Diana and I said "Hello" and that we still make her curry dish every now and then and always think of you guys when we eat it.

Best Regards
J.T.

[BigBeakie]

From colemj post #19

For DC watermakers, amp usage is the key. You may think you have enough solar (and you might actually!), but keep in mind that these outputs are rated at 13.8V, not 12V. So to get that output from a 38A unit, you will need to be running it when your solar is pumping in >38A. Few have solar arrays that do that.

Tellie,

I got the 13.8V idea from colemj in post #19 and maybe misinterpreted it. By being rated at 13.8V I thought he meant that that is the voltage required to get the rated output. If that is not the case , then that's good news.

[colemj]

Yes, the 13.8V comment came from me. However, I was talking about non-energy recovery units (sorry, I thought I made that clear with the 38A reference). The Spectra Clark pump is a different beast than the normal piston pump, and it produces pressure in a different way than direct first-stage compression. Its whole purpose is to recover energy, thus run at lower power.

So here are real-life numbers for a piston pump on a nominal 6.25gph DC watermaker (150gpd unit drawing a constant 17A):
5.4gph @ 12.5V
5.7gph @ 12.9V
5.8gph @ 13.5V
6.2gph @ 14.3V

(suck on that Rich Boren - I collected real-life data and made a table! Don't make me show you reefer data... )

So if you are not at full charging voltages, you lose 15% of your output. I have worked with several different DC brands of piston-pumped watermakers, and this is the normal trend for them - they are spec'd at full charging voltages, and not at below resting voltages.

This actually makes a stronger case for Spectra DC watermakers over any other DC units.

However, I think with your planned boat systems, you are completely missing the ball in your thinking. You should be going with a high-output AC unit instead.

I'm going to take a flyer here and suggest that anyone considering a diesel-hybrid boat with 2KW of solar and a large LiFePO battery bank is not going to be a water-miser. You will be doing laundry in a large washing machine, taking several full showers each day, washing down the boat regularly, etc. You will be using a lot of water, and will not be satisfied with 12gph no matter how you achieve it.

On the other hand, unless you are a very dedicated and creative engineer, I think that a Spectra watermaker may be the only thing working on your boat a year into owning it. Your plans are biting off big chunks of several non-standard and under-engineered systems.

I am a dedicated and creative geek, and I personally wouldn't head off into many years of remote cruising with your planned boat and systems.

Sorry about that last part, but it puts my recommendations into perspective.

Mark

[SV THIRD DAY]

I call uncle....