Watermaker - 240v vs. 12v

[Tim Good]

Hello all. Haven't been a liveaboard before but will be next year long term cruising.

On board I have an old Aquafresh watermaker. Pretty heavy duty and runs when the Genset is on. I understand it can produce reasonably high outputs. I don't think it has worked for a long while so it will probably cost me a bit to fix / maintain.

The question is, do I try and fix it or should it strip it all out and put in a new 12v watermaker to keep things simple. Has anyone used a 12v type and can they recommend them?

I have a 600L water tank on board at present.

 

[TQA]

Well decide if you are going to be running the genny if so go 240volt. If relying on a 12 v battery bank charged by solar and or wind then go the lower output Spectra route.

I have 400 w of solar and can run my Spectra on sunny days. I don't because I can fill my 150 galls cheaper than I can run the watermaker.

 

[temptress]

Hello all. Haven't been a liveaboard before but will be next year long term cruising.

On board I have an old Aquafresh watermaker. Pretty heavy duty and runs when the Genset is on. I understand it can produce reasonably high outputs. I don't think it has worked for a long while so it will probably cost me a bit to fix / maintain.

The question is, do I try and fix it or should it strip it all out and put in a new 12v watermaker to keep things simple. Has anyone used a 12v type and can they recommend them?

I have a 600L water tank on board at present.

these days go 12v (or 24v). We have a Spectra. We run it a the fridge using the solar panels. We have 540 ltrs in 3 tanks and are never short.

 

[miyagimoon]

You cannot look at it in isolation to all the other equipment you have on board. You need to look at the whole system.

What other 12v / 240v equipment do you have.

For example we have:

12v Air Cooled Fridge
12v Air Cooled Freezer
12v Auto Pilot
12v Instruments
12v Nav Lights
etc. etc.

In the Med these have quite a power drain especially in high season.

We have 240v

100A Battery Charger
Microwave
Kettle
Toaster
etc. etc.

Now due to the high drain on the batteries and that we much prefer to sail rather than motor, we also very rarely use Marina's and Harbours charge for electricity and water we run our genny every 2 or 3 days. That is of course to charge the batteries etc. Now whilst charging the batteries the genny also powers the watermaker. The genny will also run whilst we are sailing so can make water at sea as well as in nice clean anchorages.

We used to have a 12v watermaker but found that we still needed to run the genny. So when the 12v died we replaced with 240v. Less strain on the batteries and bigger quantity of water being made.

For a large output watermaker you need some serious solar panels. They do not come cheap when you take in account the cost of the panels, mountings, electric cabling and the controls.

 

[Monique]

FWIW, we installed a Dessalator Duo 100 l/hr running on both 220 VAC or 24 VDC. We expect to power via DC while at anchor and Genset while at sea.

We have 540W solar and keel cooled refer/freezer. Should be OK for us in sunny climes between 20N and 20S Latitudes.

 

[pmyatt]

This is a useful site; if you scroll down the list of items you will see "Build your own water maker"; it may help you come to a reasoned conclusion without relying on the (relatively) unsupported opinions of others.

http://www.svsoggypaws.com/presentations.htm

 

[ccscott49]

I have an aquafresh watermaker, AC600, running on 230v, from my genny. The aquafresh watermakers are fairly simple beasts and with a manual, available online, they are easy to service and repair.
If yours hasn't been used for sometime, it will probably need new membranes, not the easiest of things to fit, but can be done by anybody reasonably capable with spanners and allen keys! Even re-building the HP and LP pumps is just spanner work and all explained in the manual.

One word of warning, DO NOT buy your membranes from Aquafresh, they are 248 quid each, I just bought mine from an outfit in Rochdale for 102 quid each, very reasonable, same maker by the way.

If you don't feel confident doing them yourself, get a good mechanic type to do them for you. I would test the whole system first, if it works run the cleaning regime, but first download the manual.

I have had the 24 volt type and wasn't impressed. This one produces 90 litres an hour so plenty when battery charging etc.

One other point, if you are going to be long term liveaboard in UK, why would you need a watermaker, with 600 litres of water? And no doubt reliable water available close at hand? I am in the meddy, that's different.

 

[Tim Good]

Thanks for that feedback and advice on the membrane. We're not planning to live aboard in the Uk. Next Spring we go for a long term circumnavigation and we're pretty adventurous so likely end up in some far out places.

I have the manual so will take a look.

Any advice on firing it up after so long unused?

 

[jrudge]

Bear in mind water makers chomp power, are noisy and to produce decent water volumes run for quite a long time.

We have a 240 v one producing 140 l per hour. We hold 1000 litres and use probably 400 - 500 l per day , so to keep up with demand that is3 or so hours running.

My view. You want the highest capacity watercmaker possible so you are not running it for long. 12 v you will be producing relatively small amounts of water and it will be running for a long time ... Which wil be using power which has to come from somewhere.

240v!

 

[Tim Good]

We hold 1000 litres and use probably 400 - 500 l per day

Ok I don't ever envisage using that amount. I'm assuming your just living life as normal with two showers a day, cooking in fresh water etc? How many are you on board?

 

[sailinglegend420]

....12 v you will be producing relatively small amounts of water and it will be running for a long time....

Our 12v HRO watermaker makes 70 litres an hour. I wouldn't call that relatively small amounts of water!

We ONLY make water on the move, never at anchor, you never know what will be floating by. In the Med we do a lot of motoring and thats when we run the watermaker to provide the 24 amps needed. All our water comes from the watermaker, we never use marina or Town Quay water all season.

 

[jrudge]

There are typically 5 on board. We don't particularly set out to use water it just seemed to happen ! Our old boat had 300 l that lasted 3 days at a push. Given we now have a water maker it no longer matters as the gen is running for more than 3 hours a day anyway so I suppose dad has stopped nagging ! It is also nice to wash the boat down on anchor as opposed to sitting on a salt encrusted boat after a long ish trip.

The 12 v ones I came across we're making less than 70l so that sounds pretty good. We have hro as well ( seafari) and it was simple to install and works well. Still need to run a motor for the 24amps though so I suppose it comes down to relative price and if there are any differences in dimensions that would make install easier with either.

They are noisy though regardless of what he brochure says.

Hro manual was poor but their support on the phone was excellent. The manual missed out completely one bit of wiring so I called to ask what to do with this wire ! It also gave dodgy guidance re the bypass valve but both sorted in a phone call. Seems well made. They were also giving pretty substantial discounts whic was nice.

 

[geem]

Our watermaker is robust. It runs off 240v via our generator and we make 130 litres per hour. There is enough spare juice to run the immersion heater as well or do a bit of vacuum cleaning or boil a kettle. We only run the genny for an hour every two or three days. I like the fact that we don't challenge our batteries. The generator has only run for 100 hrs in the last year so I guess we have made in excess of 10 tonnes of water. We have been the 12v watermaker route but wouldn't go that route again. Too slow to make water and strain on batteries when limited solar output.

 

[Tim Good]

Ok I am sold. I will try to service my existing 240v system.

It is an Aquafresh and likely been stood for many years without being used. There is clear water in the filter cartridges. Providing it was shut down and cleaned correctly last time it was used, what is the likelihood that the membrane is ok?

 

[geem]

Ok I am sold. I will try to service my existing 240v system.

It is an Aquafresh and likely been stood for many years without being used. There is clear water in the filter cartridges. Providing it was shut down and cleaned correctly last time it was used, what is the likelihood that the membrane is ok?

There is no harm in trying the unit. The membrane may work fine. If it doesn't you could try a clean. This may work. A friend of mine has had the same membranes for many years with long periods of inactivity. He has three membranes in series. The output is lower then it should be but they still work. We have a 40" and a 21" in series and get 120-130 litres per hour depending on water temperature. My friend gets circa 170 litres from his old membranes. If output is low but everything else works fine, it may be worth stumping up the cash for a new membrane as they are not much money in the scale of things

 

[Tim Good]

There is no harm in trying the unit. The membrane may work fine. If it doesn't you could try a clean. This may work. A friend of mine has had the same membranes for many years with long periods of inactivity. He has three membranes in series. The output is lower then it should be but they still work. We have a 40" and a 21" in series and get 120-130 litres per hour depending on water temperature. My friend gets circa 170 litres from his old membranes. If output is low but everything else works fine, it may be worth stumping up the cash for a new membrane as they are not much money in the scale of things

Thanks. How would I know if they are poor? Just a low quantity or water or would the produced water itself be bad quality?

 

[geem]

You can buy inexpensive handheld TDS meters. Water should be less than 250 once the units has been running for 1/2 hr. If it is close to 500 it is probably time to change the membrane but try cleaning it first. If it is less than 500 it should taste ok. Certainly less than 250 will taste good.

 

[Tim Good]

You can buy inexpensive handheld TDS meters. Water should be less than 250 once the units has been running for 1/2 hr. If it is close to 500 it is probably time to change the membrane but try cleaning it first. If it is less than 500 it should taste ok. Certainly less than 250 will taste good.

Thanks. Just ordered an ebay special for £5.

 

[chrisb]

talking around Spectra seem a great idea but are prone to fail .Go for a high output device; you will need more than you imagine . Remember that if you fit outside EU you may be VAT exempt ie Trinidad

 

[geem]

talking around Spectra seem a great idea but are prone to fail .Go for a high output device; you will need more than you imagine . Remember that if you fit outside EU you may be VAT exempt ie Trinidad

I wasn't going to mention Spectra reliability but since you have I may as well throw in my bit. Whilst cruising from UK to Caribbean we met four cruisers who had fitted Spectra watermakers at great expense and they all had technical problems and were waiting for parts. Now this may be all coincidence but we didn't meet anybody with a Spectra watermaker who hadn't got problems.
I built my watermaker from second hand EBay parts. I sourced a CAT pump, second hand control panel and pressure vessels. One pressure vessel was faulty so I had to buy a brand new one. My total build cost including new membranes and s/s flexible pipes was £1500. We actually have two spare CAT pumps, a seal kit and a spare motor all within this cost. We make 120-130 litres per hour depending on seawater temperature. We have no leaks from the system and we love it