Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 16-12-2016, 10:26   #1
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 813
Images: 1
Watermaker comparison worksheet

With all the recent discussions comparing watermakers, does anyone have a comparison worksheet with make, model, 12vdc/110v, amps, gph (lph), size, cost, etc.?
Thanks
Don
__________________

Capt.Don is offline   Reply With Quote
Old 17-12-2016, 18:11   #2
Registered User

Join Date: Jan 2013
Location: Seward, AK
Boat: Rawson 30 PH
Posts: 145
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Capt.Don View Post
With all the recent discussions comparing watermakers, does anyone have a comparison worksheet with make, model, 12vdc/110v, amps, gph (lph), size, cost, etc.?
Thanks
Don
I found one a long time ago, but have since lost it. I'm considering building one in excel. Any more categories that might need to be added?
__________________

joel383 is offline   Reply With Quote
Old 17-12-2016, 18:15   #3
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 30,009
Re: Watermaker comparison worksheet

I'd add AH per gl or liter for the DC ones
a64pilot is offline   Reply With Quote
Old 24-12-2016, 19:51   #4
Registered User

Join Date: Sep 2016
Location: Klamath Falls or, and Moss Landing Ca
Boat: Hunter 25, Santana 20, Hallberg RASSY 33 " Mistral" San Juan 21 MKI
Posts: 275
Re: Watermaker comparison worksheet

I'm saving my pennies for a water maker aswell. I literally just received an email from Rich, regarding his water maker. I got the reply in roughly 45 minutes, I'm impressed.

I've already got a 2000 Honda on the boat, so I'm going that route, I'd like to,share my idea, and seek constructive criticism of my idea.

I've got a composting toilet on lay away, I'll be putting this into my boat obviously in the existing head.

My thoughts are that since a composting toilet needs zero water that I'll use that thru hull fitting to plum into my water maker. No new holes, and using the existing thru hull.

I'm thinking or hoping to do the bottom soon, and would do that transition at that time.

And change out to,a new clean thru hull fitting.

I'll mount my 2000 Honda in the aft compartment on a stand alone shelf. I'll tee the exhaust from the Honda exhaust, into my diesel motors exhaust, aft of the diesel motors Anti syphon, very near where the exhaust exits the boat.

Both systems will be protected by their own independent anti syphon exhaust pipes.

Does this sound reasonable, anybody see a problem.

I want to,keep the aft deck clutter free, and the gen set clean as possible, not in salt water all the time.

Is their a better way?

Dirk
Dirk Williams is offline   Reply With Quote
Old 24-12-2016, 21:02   #5
Registered User
 
Captain Bill's Avatar

Join Date: Apr 2008
Location: Punta Gorda, Fl
Boat: Endeavourcat Sailcat 44
Posts: 2,769
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Dirk Williams View Post
I'm saving my pennies for a water maker aswell. I literally just received an email from Rich, regarding his water maker. I got the reply in roughly 45 minutes, I'm impressed.

I've already got a 2000 Honda on the boat, so I'm going that route, I'd like to,share my idea, and seek constructive criticism of my idea.

I've got a composting toilet on lay away, I'll be putting this into my boat obviously in the existing head.

My thoughts are that since a composting toilet needs zero water that I'll use that thru hull fitting to plum into my water maker. No new holes, and using the existing thru hull.

I'm thinking or hoping to do the bottom soon, and would do that transition at that time.

And change out to,a new clean thru hull fitting.

I'll mount my 2000 Honda in the aft compartment on a stand alone shelf. I'll tee the exhaust from the Honda exhaust, into my diesel motors exhaust, aft of the diesel motors Anti syphon, very near where the exhaust exits the boat.

Both systems will be protected by their own independent anti syphon exhaust pipes.

Does this sound reasonable, anybody see a problem.

I want to,keep the aft deck clutter free, and the gen set clean as possible, not in salt water all the time.

Is their a better way?

Dirk
Since the Honda is gasoline powered you will need to make sure that the compartment complies with USCG ventilation requirements. I don't know what the laws are in California, but in Florida they can confiscate your boat for having gasoline in an improperly ventilated compartment. Unless you have some weird dry stack exhaust on the diesel the exhaust behind the siphon is only exposed to water cooled exhaust. Several hours of running uncooled genset exhaust through it might create problems. Also the honda is air cooled and might have cooling issues in a restricted compartment.
Captain Bill is offline   Reply With Quote
Old 24-12-2016, 22:03   #6
Registered User

Join Date: Sep 2016
Location: Klamath Falls or, and Moss Landing Ca
Boat: Hunter 25, Santana 20, Hallberg RASSY 33 " Mistral" San Juan 21 MKI
Posts: 275
Re: Watermaker comparison worksheet

Thank you for your reply, Capt Bill. I'm not tracking, so,if,my gem set was diesel, im gtg? And describe what kind of damage could occur from running the gen set exhaust into the existing diesel exhaust.

I'm trying to imagine what your describing. Is the issue the gen set exhaust, or the wet exhaust on the boats exhaust. Would you mind clarifying .

And thank you. I, just trying to,make a system work.

And Merry Christmas.

Dirk
Dirk Williams is offline   Reply With Quote
Old 24-12-2016, 22:39   #7
Senior Cruiser
 
newhaul's Avatar

Cruisers Forum Supporter

Join Date: Sep 2014
Location: puget sound washington
Boat: 1968 Islander bahama 24 hull 182, 1963 columbia 29 defender. hull # 60
Posts: 8,497
Re: Watermaker comparison worksheet

Ok dirk the.diesel mains exhaust is water.cooled so the.hose is.rubber not metal . The hondas exhaust is air cooled and will get hot and melt the diesels exhaust hose as well as the heat could cause major dammage to the transom where it exits.
__________________
Non illigitamus carborundum
newhaul is offline   Reply With Quote
Old 25-12-2016, 02:38   #8
Registered User
 
Dave_S's Avatar

Join Date: Jun 2016
Location: Brisbane Australia
Boat: Schionning Waterline 1480
Posts: 1,308
Re: Watermaker comparison worksheet

Quote:
Originally Posted by joel383 View Post
I found one a long time ago, but have since lost it. I'm considering building one in excel. Any more categories that might need to be added?
I'm looking for portable models so it doesn't have to be in the boat all the time. If it's easy can you add portable,
petrol driven and 240Vdc models.
__________________
Regards
Dave
Dave_S is offline   Reply With Quote
Old 25-12-2016, 03:28   #9
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 13,484
Images: 14
Re: Watermaker comparison worksheet

Quote:
Originally Posted by newhaul View Post
Ok dirk the.diesel mains exhaust is water.cooled so the.hose is.rubber not metal . The hondas exhaust is air cooled and will get hot and melt the diesels exhaust hose as well as the heat could cause major dammage to the transom where it exits.
Also the problem of back pressure for the exhaust if it exits under water or has to pass through a water lock. Firstly the Honda petrol engine won't like it and there is a very real risk the exhaust gasses will leak out into the boat through the slightest hole.

We always put the honda on the deck and moved it around depending on wind direction so the exhaust went overboard.

Seem to remember the Honda doesn't like running tipped over at an angle preferring a flat horizontal surface.
Pete7 is offline   Reply With Quote
Old 25-12-2016, 03:54   #10
Registered User

Join Date: Aug 2015
Location: Marina del Rey
Boat: Hunter 31
Posts: 1,097
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Capt.Don View Post
With all the recent discussions comparing watermakers, does anyone have a comparison worksheet with make, model, 12vdc/110v, amps, gph (lph), size, cost, etc.?
Thanks
Don
I put together a spreadsheet when I was selecting a watermaker. I have used some data from vendor sites but the core of the analysis was to compare different membranes and mostly DC vs. AC. Most manufacturers use the same Dow membranes and the setup is very similar across vendors. In a nutshell:

1) DC is much more efficient than AC and this is just the nature of electric motors. If you look at HRO's Mini 170, the DC version uses 29 amps @ 12V, while the AC version uses 6 amps at 115V. Clearly, once you get above a certain size you have to go to AC because the DC amperages become unmanageable.

2) It is OK to run the membrane at a high recovery rate up to 20%. This reduces power requirements (makes a 30 amp DC watermaker possible) but clogs the membrane over time. Still, you should look at the membranes as replaceable items due to their very low cost. For example, there are a number of watermakers, the HRO Mini 170, one sold on ebay and one you can put yourself that use 1/3 hp motor at 27 amps to make 6 gpd. This seems to be the sweetspot for DC. You can either build such a watermaker yourself from parts, talk to Rich and Tellie on the forum or go to ebay. It will cost you around $2,000 and will produce water at 4 amps/gallon.

3) Spectra will cost three times as much and produce water at three times lower amperage per gallon. By far the best efficiency possible.

The spreadsheet is an approximation only, some numbers are just estimates:
Attached Files
File Type: xls Watermakers.xls (35.5 KB, 184 views)
Pizzazz is offline   Reply With Quote
Old 25-12-2016, 04:34   #11
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 13,484
Images: 14
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Capt.Don View Post
With all the recent discussions comparing watermakers, does anyone have a comparison worksheet with make, model, 12vdc/110v, amps, gph (lph), size, cost, etc.? Thanks Don
How about the attached as a starter? I have used litres for the water quantity since imperial and US gallons are different and might cause confusion with CF members outside the US. Prices are in US$ as a world currency.

Feel free to download, add to the spreadsheet and then upload to the thread.

Pete
Attached Files
File Type: xls CF Watermaker Review.xls (32.5 KB, 124 views)
Pete7 is offline   Reply With Quote
Old 25-12-2016, 05:06   #12
Registered User

Join Date: Jun 2005
Posts: 253
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Pizzazz View Post
I put together a spreadsheet when I was selecting a watermaker. I have used some data from vendor sites but the core of the analysis was to compare different membranes and mostly DC vs. AC. Most manufacturers use the same Dow membranes and the setup is very similar across vendors. In a nutshell:



2) It is OK to run the membrane at a high recovery rate up to 20%. This reduces power requirements (makes a 30 amp DC watermaker possible) but clogs the membrane over time
. Still, you should look at the membranes as replaceable items due to their very low cost. For example, there are a number of watermakers, the HRO Mini 170, one sold on ebay and one you can put yourself that use 1/3 hp motor at 27 amps to make 6 gpd. This seems to be the sweetspot for DC. You can either build such a watermaker yourself from parts, talk to Rich and Tellie on the forum or go to ebay. It will cost you around $2,000 and will produce water at 4 amps/gallon.

3) Spectra will cost three times as much and produce water at three times lower amperage per gallon. By far the best efficiency possible.

The spreadsheet is an approximation only, some numbers are just estimates:
Running your RO at 20% recovery will really clog it up?? How and with what? Is this one of those little membranes making 6 to 24 for or something?? I have a 4" x 40" membrane on my watermaker that runs at 35% recovery and has for five years without plugging up. Of course it's flushed with fresh water after each run. Larger systems run at up to 45% recovery with membrane life expectancy at 7 years with proper pre treatment and good SDI's. I have data if you would like to see.
Jsta_Rebel is offline   Reply With Quote
Old 25-12-2016, 06:54   #13
Registered User
 
Captain Bill's Avatar

Join Date: Apr 2008
Location: Punta Gorda, Fl
Boat: Endeavourcat Sailcat 44
Posts: 2,769
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Dirk Williams View Post
Thank you for your reply, Capt Bill. I'm not tracking, so,if,my gem set was diesel, im gtg? And describe what kind of damage could occur from running the gen set exhaust into the existing diesel exhaust.

I'm trying to imagine what your describing. Is the issue the gen set exhaust, or the wet exhaust on the boats exhaust. Would you mind clarifying .

And thank you. I, just trying to,make a system work.

And Merry Christmas.

Dirk
Marine diesel gensets have water cooled exhausts like marine diesel engines and will work fine in your application though the installation will be much more complicated and the unit 8 10 times more expensive than your Honda. Substituting an air cooled diesel genset designed for land use will not solve the problem as they do not have a water cooled exhaust. As Newhaul pointed out the problem is the temperature of the exhaust. The temperature of the exhaust could quite easily damage components of the exhaust system. Should they develop a leak you would then be putting carbon monoxide inside your hull below deck. We don't want to see your name on the list of Darwin award candidates.

If your engine exhaust is at or below water level back pressure could also be a problem.

If you are looking to do this on the cheap just run the Honda on the deck and consider it a throw away item. You'll probably still get 3-5 years out of it and it will be 25-50 years before you spend as much money as a proper marine diesel genset would cost.
Captain Bill is offline   Reply With Quote
Old 25-12-2016, 08:31   #14
Registered User

Join Date: Sep 2016
Location: Klamath Falls or, and Moss Landing Ca
Boat: Hunter 25, Santana 20, Hallberg RASSY 33 " Mistral" San Juan 21 MKI
Posts: 275
Re: Watermaker comparison worksheet

Ok, I see the problem. Deck use seems to be the logical solution should I use this Honda 2000.which is the plan.

My initial post worked in my mind, had not thought about back pressure, and gas, under the deck. The aft area I'm certain is not gas approved either.

Thank you all for your input. Problem solved. My goal is to efficiently run a water maker as quietly and efficiently as possible. I'm trying to win my wife back to sailing.

I blew it being a Capn Bly, when racing boats a few years back. I'm hoping that she will consider sailing long range if our boat has some creature comforts. With a 40 gallon water tank, I need the ability to make water.

Capn Bill, everybody else, thank you all so much. I know I'm a pain in the butt, asking all these questions. I'm trying to learn a better way, and do it for a reasonable cost.

Merry Christmas, and a Happy New Year to,all.

Dirk
Dirk Williams is offline   Reply With Quote
Old 25-12-2016, 08:54   #15
Sponsoring Vendor
 
Tellie's Avatar

Community Sponsor

Join Date: Oct 2007
Location: Hollywood, Fl.
Boat: FP Athena 38' Poerava
Posts: 3,444
Re: Watermaker comparison worksheet

Quote:
Originally Posted by Dirk Williams View Post
Ok, I see the problem. Deck use seems to be the logical solution should I use this Honda 2000.which is the plan.

My initial post worked in my mind, had not thought about back pressure, and gas, under the deck. The aft area I'm certain is not gas approved either.

Thank you all for your input. Problem solved. My goal is to efficiently run a water maker as quietly and efficiently as possible. I'm trying to win my wife back to sailing.

I blew it being a Capn Bly, when racing boats a few years back. I'm hoping that she will consider sailing long range if our boat has some creature comforts. With a 40 gallon water tank, I need the ability to make water.

Capn Bill, everybody else, thank you all so much. I know I'm a pain in the butt, asking all these questions. I'm trying to learn a better way, and do it for a reasonable cost.

Merry Christmas, and a Happy New Year to,all.

Dirk

Trying not to be biased, I know cost is always a factor, but with a 40 gallon water tank you should seriously be looking at a DC system. Long range cruising makes having long range help more attractive. Trying to spreed sheet watermakers for comparison usually is more apples and oranges than most people realize. There is no one size fits all watermaker for everyone, even on identical boats. Your needs and your boats capabilities will be a far more accurate deciding factor than just comparing one watermaker to the next as far as performance and energy usage. First you should give us an idea of how you are powering and charging your boats electrical needs besides a portable gas generator.


Merry Christmas to all from all of us at
HaldenMarineService,com

Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators
Tellie is offline   Reply With Quote
Reply

Tags
water, watermaker

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Power consuption worksheet ozmike Electrical: Batteries, Generators & Solar 4 04-01-2013 04:59
Anchor Surface Area Comparison - Manson Supreme vs CQR Maine Sail Anchoring & Mooring 96 07-09-2011 09:53
Sextant Worksheet Question Ron Blackburn Navigation 0 29-07-2011 03:02
Efficient Powerboats vs Efficient Sailboats (Running Cost Comparison) cat man do Powered Boats 142 04-01-2010 15:52
Electric and Diesel comparison Whimsical Multihull Sailboats 90 04-08-2008 15:38

Advertise Here


All times are GMT -7. The time now is 02:55.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.