Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 03-09-2010, 23:11   #1
Registered User
Alan N Crichton's Avatar

Join Date: Jul 2008
Location: Cape Town South Africa
Boat: Admiral Catamaran 38ft
Posts: 33
Watermaker - 12vdc, 220vac, or Engine-Driven

I am currently looking for a water maker but given the high current drawn I am tempted to go for the high pressure pump that is driven by V-belt from the main engine. (Ech2otec) During voyages I will run the motor every 3 or 4 days for a couple of hours - have 1000l (~ 200 gallon) of fresh water storage. I have solar panels , invertor and my wind generator is ordered but still think of maximising efficiency when the engine is running - charge batteries , make water , do washing , have hot shower etc all in the couple of hours every few days. Anyone with experience of these mechnical drive types and the things to watch out for ?

Alan N Crichton is offline   Reply With Quote
Old 03-09-2010, 23:33   #2
Registered User
Albro359's Avatar

Join Date: Jun 2009
Location: Elyse is in Fiji
Boat: Amel Super Maramu 2000
Posts: 509
They don't all draw high current..there a re a lot of posts on here about this.
3rd generation watermakers give the best output per amp...I have a Schenker that produces 35litres per hour for a current draw of only 8-9 Amps. I run it every day when I run the engine for 90 minutes which produces :
50 litres of fresh water
Heats the hot water cylinder
Keeps the freezer down below -20degC
fully charges my 420Ah AGM battery bank
I don't have solar panels or a wind generator
You have to run yoiur engine why not go with a super efficient watermaker rather then a simplistic 1st generation unit ?

See you out there ....... Alan S.V. Elyse
Albro359 is offline   Reply With Quote
Old 04-09-2010, 04:38   #3
Registered User

Join Date: Oct 2005
Posts: 120
do not recommend belt driven

We had a belt driven WM over the last 4 years and it has caused more problems and cost more than a 12V one would have, so we are in the process of converting it to DC now.
I would strongly recommend to go for a DC system.
Belt driven system problems include:
- cost of mounting it on the engine (almost $1000 when all was said and done after the first one in Aluminum broke. Note that the HP pump is very heavy)
- damage (or wear) to the engine
- can't use it while under way (too restricted rpm range)
- Have to run the engine specially for the WM

Can't comment yet on the DC system, we should have it up and running in a few days.
claire is offline   Reply With Quote
Old 04-09-2010, 06:31   #4
Eternal Member
capt_douglas's Avatar

Join Date: May 2003
Location: Ft. Lauderdale, FL
Boat: Vancouver 36 cutter????
Posts: 620
Send a message via Skype™ to capt_douglas
I've got a PUR-40 that makes about 1.5gph@4A. Their 80gpd model takes around 9A, iirc. I try to conserve water and collect it when it's available and cheap.

I've got engine driven refrigeration and don't have another belt slot for a water maker high pressure pump. I'm trying to avoid running the engine so the 12VDC version is what works for me.

The type of water maker would be dictated by the water and power requirements you have I think. If you're going to run the engine to recharge batteries/refrigeration/water maker and have the PTO/belt space, you might be better off especially if you use a lot of water.
Capt. Douglas Abbott
USCG/MCA IV/M.I./C.I. 500-ton Oceans
capt_douglas is offline   Reply With Quote
Old 04-09-2010, 06:45   #5
Senior Cruiser
JusDreaming's Avatar

Cruisers Forum Supporter

Join Date: Jul 2004
Location: Stuart, FL & Bahamas Cruising
Boat: Lagoon 37
Posts: 878
Images: 13
I built our's and it is engine driven, and has worked flawlessly. The only problem we have is it is designed for low RPM, (1800-2000), and if you go over that rpm it tends to draw a vacuum. It is nice to charge everything and make water while heading to the next anchorage
Denny and Diane
Lagoon 37
"The only way to get a good crew is to marry one." -Eric Hiscock
JusDreaming is offline   Reply With Quote
Old 04-09-2010, 08:32   #6
Registered User
c.spots's Avatar

Join Date: Jul 2007
Location: Now in Davao, the Philippines.
Boat: Leopard 40 catamaran
Posts: 121
Send a message via Skype™ to c.spots
If you are planning on offshore cruising, consider a 12V system. The redundancy of the power source is a good safety factor. If your engine, generator, or inverter fail..... Most of us have several ways to get 12V power. I like the Cape Horn extreme, since it is energy efficient, and has pump redundancy too.
Don't bother with the added expense, complexity, and unreliability of an automated unit. A rain catchment can get you free water, but isn't reliable in most places.
If you insist on a long hot fresh water shower every day, consider a 110 unit, and maybe get a genset (or two cheap gas ones, so you have a spare?) and/or a spare inverter.
I prefer to cut the cord, and can produce 18 gallons an hour with power from my solar panels.
Robert W.

Life shouldn't be a race to the finish line - enjoy the journey.
c.spots is offline   Reply With Quote
Old 05-09-2010, 09:30   #7
Registered User

Join Date: May 2009
Location: Massachusetts
Boat: 40' Silverton Aftcabin with twin Crusaders
Posts: 1,444
This thread has me excited me to look into building one. Of course, it will be a winter project. I will be back with many questions as I learn and search out information from those who already experienced the thrill of building their own. Mine will operate from my generator via AC.

More later in a new thread so I don't hijack this one.

foggysail is offline   Reply With Quote
Old 05-09-2010, 09:48   #8
Registered User
Jon Hacking's Avatar

Join Date: Sep 2010
Location: Currently cruising Southern Indonesia, heading for peninsular Malaysia
Boat: Wauquiez 45' (now 48') catamaran
Posts: 514
Send a message via Skype™ to Jon Hacking
If you're looking for efficiency (liters/amp-hour of electricity) then it's hard to beat the 12-volt units that recycle the high pressure water from the membrane. (If you have a gen-set, then you're probably looking more for best $ for however many liters/hour you need.)

One thing many folks new to watermakers don't realize is that watermakers like to be run every day, especially in the tropics. You can run them just to flush them, but they want to be run.

FWIW, I've been using an old Spectra 200 that I upgraded myself to a 380 (by adding a 2nd pump). Been running it for 9 years now. It hasn't been trouble free (few watermakers are) but it's worked for us & our 2 teens. We usually run it for ~2 hours after the solar panels have brought the batteries up & the charge controller is starting to regulate.

I've posted an article on watermakers in our Cruiser Information section of our website (direct link here).
-- Jon Hacking s/v Ocelot
Jon Hacking is offline   Reply With Quote
Old 05-09-2010, 11:11   #9
Registered User
Dreaming Yachtsman's Avatar

Join Date: Nov 2005
Location: Beaverton, OR
Posts: 486
Images: 5
Send a message via Skype™ to Dreaming Yachtsman
We have been VERY happy with our Spectra Catalina model unit. We have 3 ways to generate 12 V DC so really enjoy the flexibility with this system. It produces 10-12 gallons per hour, depending on water temp, salinity, and battery voltage and draws 15-17 amps. On a sunny day, our solar panels provide enough charge to offset that current draw (provided the wife isn't making ice). With just the two of us aboard, we run it 3-4 hours about every 3-4 days and have plenty of water for drinking, washing dishes, fresh water flushes of the Vacuflush toilets, and showers. Although not the norm, we have gone weeks at anchor in sunny weather without needing to start the auxiliary generator or main engine.
Formerly S/V Yachtsman's Dream
Go sailing now. Life is too short not to enjoy it.
Dreaming Yachtsman is offline   Reply With Quote
Old 05-09-2010, 12:13   #10
Registered User

Join Date: Jul 2010
Location: Montana
Posts: 391
The fewer liquid-filled things attached to my engine, the easier I rest. The vibration isnt good for them.
Healer52 / Lisa, Rick and Angel the Salty Dog
Currently on the hard, looking for a boat
Healer52 is offline   Reply With Quote
Old 05-09-2010, 15:14   #11

Join Date: Mar 2004
Posts: 1,167
If you are motoring anyway, why would you bother with the huge complexity of electrics? Converting energy into an alternator with a loss, then battery juice, with a loss, then into a motor , again with a loss. Nothing simpler and easier to repair than a belt drive. A friend who builds watermakers, says electric drives are the main source of problems. I built my own engine driven 540 GPD watermaker for around $750. No problems.
Brent Swain is offline   Reply With Quote
Old 05-09-2010, 16:05   #12
Registered User

Join Date: Sep 2009
Location: Antigua
Boat: Oyster 485
Posts: 94
Send a message via Skype™ to sobriyah
I installed a Katadyn 160 watermaker five years ago. Easy to install. Modular. No electronics to go wrong. Draws about 8A, and produces 30 litres an hour. Run it almost every day and am still on the original membrane. Its a good piece of kit. I was advised (by Katadyn) not to mount it in the engine compartment due to ambient temperature. Makes a fair bit of noise though.
sobriyah is offline   Reply With Quote
Old 16-09-2010, 13:10   #13
Registered User

Join Date: Sep 2008
Location: Chesapeake Bay
Boat: MacGregor65- s/vSunsets
Posts: 46
My DH installed a Katydyn 80 last weekend. The pump is HEAVY!! I strongly recommend cutting out a cardboard template when you are planning out the install. (It's a lot easier on you than trying to hold the damn thing in place while he figures out where the membrane should go and which drill bit he's going to use.) You can just tape the template in place and then finish laying out the other pieces and drilling your pilot holes. I thought it was a brilliant idea.
s/v Sunsets is offline   Reply With Quote
Old 16-09-2010, 13:35   #14
Registered User

Join Date: Dec 2009
Posts: 3,016
Images: 4
Originally Posted by sobriyah View Post
I installed a Katadyn 160 watermaker...Draws about 8A, and produces 30 litres an hour
Katadyn datasheet claims 29 l/h max (8 g/h) at 18A@12V (12A@24V) producing 500ppm (avg) water. That's at the limit of what can be called freshwater. Does it taste a bit salty?
daddle is offline   Reply With Quote
Old 16-09-2010, 14:27   #15
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 6,714
Images: 14
Says salt water rejection is 98.4%, isn't that enough?

Think he missed typed 8 instead of 18 ah which might be more realistic.


Pete7 is offline   Reply With Quote

engine, watermaker

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine-Driven Compressors tartanss Plumbing Systems and Fixtures 8 27-01-2013 13:13
For Sale: Katadyn PowerSurvivor 40E / 12vdc Watermaker Alan Stewart Classifieds Archive 7 07-09-2010 13:26
Engine-Driven Watermaker invicta2 Plumbing Systems and Fixtures 4 07-08-2010 08:41
12vdc Reverse Osmosis / UV Filtration - Not Watermaker Sea Conquest Provisioning: Food & Drink 30 23-11-2009 12:57
Engine driven refrigeration Wahoo Sails Plumbing Systems and Fixtures 8 20-12-2006 01:47

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:18.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.