Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 19-02-2015, 09:51   #16
Registered User
 
leftbrainstuff's Avatar

Join Date: May 2011
Location: San Francisco and Australia
Boat: Liberty 458
Posts: 1,978
Re: Run water heater from inverter?

Your water heater is one high duty cycle, high current load. I think you might drain the house bank. We have 675 Ahrs house bank and 280W solar which is probably a little small to heat hot water without punishing the batteries.

We heat our hot water from either shore power, generator coolant, engine coolant or with our espar water heater via an air to water heat exchanger.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app
__________________

__________________
leftbrainstuff is offline   Reply With Quote
Old 19-02-2015, 09:54   #17
Registered User
 
leftbrainstuff's Avatar

Join Date: May 2011
Location: San Francisco and Australia
Boat: Liberty 458
Posts: 1,978
Re: Run water heater from inverter?

Quote:
Originally Posted by W3GAC View Post
Yes. I just have a standard 5 gal Ratian w/o any extra insulation. We practice the Navy shower technique of low water sink & shower use. The engine has a 180 degree thermostat so the hot water is frightfully hot compared to home settings and only takes a crack of the hot valve to get normal temp shower/ KP water. And actually wrapping the hot water tank would likely extend the shelflife of the hot water perhaps to 3 and maybe even still usable to a 4th day if not diluted much by usage. Good idea I'll try it myself.

For washing dishes I put a little Dawn in about half cup of very hot water and use one of those brushes designed for dish washing (9" handle. Dawn seems to do a much better job cutting grease than the other dishwashing products we tried, even with cold water. Once all the stuff has been brushed off and temporarily stacked (still soapy) I use just a trickle of water to rinse the items one by one. You can clean up after a meal for four with 1/2 to 3/4 gal of water and practically no hot water. In the Caribbean we did that final cold water rinse over a pot to capture that soapy water to use again on mask/ snorkel... what ever else only needed cooler soapy water to work.


Sent from my iPhone using Cruisers Sailing Forum
Our water heater keeps water hot for a day or so.





Quote:
Originally Posted by rwidman View Post
My water is still hot the next morning after sitting 15 hours or more. I don't remember the brand of heater but it's whatever came on the boat, nothing special.

Like W3GAC's heater my water comes out the same temperature as the engine coolant so that can be 175 degrees or so. There should be a tempering valve but there isn't. We just know hot it is and use it accordingly.


Sent from my SM-N900T using Cruisers Sailing Forum mobile app
__________________

__________________
leftbrainstuff is offline   Reply With Quote
Old 19-02-2015, 15:59   #18
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,821
Re: Run water heater from inverter?

Quote:
Originally Posted by cwyckham View Post
Wow. You can keep your hot water hot (or warm) for more than a few hours? I think I need to find a way to insulate my tank better!

Oddly, that never occurred to me.
We use our 1500 watt inverter to heat water.
Besides rebuilding our fridge/freezer, we also reinsulated our water tank with this:


Aspen Aerogel Spaceloft Insulation Hydrophobic Mat per Linear Foot 5mm | eBay

Solar keeps everything on the boat running, watermaker, HAM, wifi computer ElectroScan, radar autopilot etc.

One 200 aH Lithium Phosphate battery bank for the whole boat including engine start.

It's all about BALANCE !

__________________
Memento,homo, quia pulvis es, et in pulverem reverteris.
senormechanico is offline   Reply With Quote
Old 19-02-2015, 17:06   #19
Registered User

Join Date: Oct 2012
Location: Currently Tasmania after Pacific crossing
Boat: Catalina 42
Posts: 217
Re: Run water heater from inverter?

Exactly, it's all about balance!

I'm encouraged and learning from all your posts that I can indeed heat the water by using the inverter.

So, if the 2000w inverter runs the 1500w heater element for 1/2 hour it's drawing 50amp/hr from the 850amp/hr battery bank, not such a huge drawdown.

The solar panels are very capable of producing 25amps per hour for 2 hours or more on a good day so I think that should cover it!
Currently the batteries are at full voltage by lunchtime so plenty of time to make up the extra 50amp/hr!

While sitting at anchor for a few days, I'd like to have hot water without having to start the motor or run the Honda generator.

I just need to get the 120v wiring changed and checked.


Sent from my iPad using Cruisers Sailing Forum
__________________
Amnesia II is offline   Reply With Quote
Old 19-02-2015, 17:13   #20
Registered User
 
Rustic Charm's Avatar

Join Date: Jun 2011
Location: Tasmania, Australia
Boat: Bieroc 36 foot Ketch
Posts: 4,898
Re: Run water heater from inverter?

Quote:
Originally Posted by Amnesia II View Post
The solar panels are very capable of producing 25amps per hour for 2 hours or more on a good day so I think that should cover it!

Sent from my iPad using Cruisers Sailing Forum
Seriously? What size solar panels do you have that will give you 25amps an hour? I want some.
__________________
Rustic Charm is offline   Reply With Quote
Old 19-02-2015, 17:19   #21
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
Re: Run water heater from inverter?

Keep in mind that you only have 425 usable AH in that bank to keep from drawing down more than 50%. 50 AH will be about 12% of available AH. You will be using other power at the same time. But it is doable if you manage your usage. Chuck
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 19-02-2015, 18:12   #22
Registered User

Join Date: Oct 2012
Location: Currently Tasmania after Pacific crossing
Boat: Catalina 42
Posts: 217
Re: Run water heater from inverter?

I have 3 x 200w panels over the Bimini, too heavy I know but I've had no issues in encountering persistent 40 knot gales!


Sent from my iPad using Cruisers Sailing Forum
__________________
Amnesia II is offline   Reply With Quote
Old 19-02-2015, 18:19   #23
Registered User

Join Date: Oct 2012
Location: Currently Tasmania after Pacific crossing
Boat: Catalina 42
Posts: 217
Re: Run water heater from inverter?

Quote:
Originally Posted by AnchorageGuy View Post
Keep in mind that you only have 425 usable AH in that bank to keep from drawing down more than 50%. 50 AH will be about 12% of available AH. You will be using other power at the same time. But it is doable if you manage your usage. Chuck

I guess my intention is to be heating water during daytime sunshine when possible and when required the motor can be run to have the 180 amp alternator feed the battery bank( on just above idling puts out 75amps approx).


Sent from my iPad using Cruisers Sailing Forum
__________________
Amnesia II is offline   Reply With Quote
Old 19-02-2015, 18:20   #24
Registered User

Join Date: Apr 2013
Location: So Cal
Boat: Catalina 30
Posts: 943
Re: Run water heater from inverter?

Yaknow, somewhere I read about 12v heater elements. IIRC they're pretty small, like 400w or something. But that'd be a fantastic diversion load for folks with lots of solar. Once the batts are full, pump the solar into the WH.
__________________
jeepbluetj is offline   Reply With Quote
Old 19-02-2015, 18:24   #25
Registered User
 
Rustic Charm's Avatar

Join Date: Jun 2011
Location: Tasmania, Australia
Boat: Bieroc 36 foot Ketch
Posts: 4,898
Re: Run water heater from inverter?

Quote:
Originally Posted by Amnesia II View Post
I have 3 x 200w panels over the Bimini, too heavy I know but I've had no issues in encountering persistent 40 knot gales!


Sent from my iPad using Cruisers Sailing Forum
I think your anticipated 25 A an hour is a bit optimistic then. In optimal circumstances I think you will get around 18A, but that's running at best.

BUT, me no electrical guru. All I really know is the stuff bites when you touch the end of a wire connected to the battery to your tongue.
__________________
Rustic Charm is offline   Reply With Quote
Old 19-02-2015, 18:43   #26
Registered User

Join Date: Oct 2012
Location: Currently Tasmania after Pacific crossing
Boat: Catalina 42
Posts: 217
Re: Run water heater from inverter?

Quote:
Originally Posted by Rustic Charm View Post
I think your anticipated 25 A an hour is a bit optimistic then. In optimal circumstances I think you will get around 18A, but that's running at best.

BUT, me no electrical guru. All I really know is the stuff bites when you touch the end of a wire connected to the battery to your tongue.


Not so, 600w @ 12volts in theory = 50amps

I regularly see 36amps going to the batteries on a good overhead sunny day!


Sent from my iPad using Cruisers Sailing Forum
__________________
Amnesia II is offline   Reply With Quote
Old 19-02-2015, 18:45   #27
Don't ask if you can't handle it
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 12,305
Re: Run water heater from inverter?

Quote:
Originally Posted by Rustic Charm View Post
I think your anticipated 25 A an hour is a bit optimistic then. In optimal circumstances I think you will get around 18A, but that's running at best.

BUT, me no electrical guru. All I really know is the stuff bites when you touch the end of a wire connected to the battery to your tongue.
I bet he can get close to 50 amps during good conditions and under load running an inverter to supply the water heater.
__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is offline   Reply With Quote
Old 19-02-2015, 18:51   #28
Registered User

Join Date: Jan 2013
Posts: 203
Re: Run water heater from inverter?

Here is the math, 3 X 200 watt panels = 600 watt / 13.5 charging voltage = 44 amps.

About 5.5 hours a day = 242 ah per day.

Nice system, I have about the same and get the same kind of output.

It`s just math
__________________
twinboat is offline   Reply With Quote
Old 19-02-2015, 19:37   #29
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 7,909
Re: Run water heater from inverter?

Quote:
Originally Posted by cwyckham View Post
Wow. You can keep your hot water hot (or warm) for more than a few hours? I think I need to find a way to insulate my tank better!

Oddly, that never occurred to me.
Ive got a well insulated Isoterm tank that will keep water warm for hours. Have never collected data on its thermal performance, but have gotten warm water out of it after surprisignly long times.

Also has mixing valve at the outlet to blend hot/cold water. Dont need engine heated temps here in the tropics so blending down to "warm" is good and extends warm water supply.
__________________
belizesailor is offline   Reply With Quote
Old 19-02-2015, 19:50   #30
Registered User

Join Date: Oct 2012
Location: Currently Tasmania after Pacific crossing
Boat: Catalina 42
Posts: 217
Re: Run water heater from inverter?

Quote:
Originally Posted by twinboat View Post
Here is the math, 3 X 200 watt panels = 600 watt / 13.5 charging voltage = 44 amps.

About 5.5 hours a day = 242 ah per day.

Nice system, I have about the same and get the same kind of output.

It`s just math


Quite right, I love the idea of the boat being totally self sufficient and not have to worry about how any lights are on or wondering if there's enough battery power to run the fridge, microwave and all the gizmos & gadgets.

So....just have to sort out the water heating, or the wiring configure.

Love those long lazy days on the anchor!


Sent from my iPad using Cruisers Sailing Forum
__________________

__________________
Amnesia II is offline   Reply With Quote
Reply

Tags
inverter, water

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
Isotherm Freezer - Run, Stop, Run, Stop... Cruisin Cat Electrical: Batteries, Generators & Solar 8 24-04-2014 19:06
Hot Water Heater / Block Heater? - 3GM30 BareProductions Engines and Propulsion Systems 9 23-02-2013 19:12
Run water heater via inverter? Bash Electrical: Batteries, Generators & Solar 27 10-01-2013 08:41
Will Yamaha EF2000iS inverter/generator run a Nespresso coffee machine? timj Electrical: Batteries, Generators & Solar 3 07-05-2012 17:27
Gas Water Heater or Combined Calorifier / Immersion Heater ? simonmd Plumbing Systems and Fixtures 5 30-12-2010 08:50



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:32.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.