Unlimited Hot Water on Sailboat

[WhataWorld!]

I was wondering how to get unlimited hot water on a catamaran? I will install a watermaker, so I would need some sort of in-line water heater. Does anyone have any experience with this? Thanks for your help

[Maren]

Usually the problem is not an unlimited supply of hot water, but an unlimited supply of water.

[sarafina]

my

produces endless hot water...
this

solves the shower issue...

[S/V Illusion]

Whataworld:

how big a propane tank do you have?
or
how big a battery bank do you have?


Science 101:
Hot water requires energy; unlimited hot water requires unlimited energy

[WhataWorld!]

Originally Posted by S/V Illusion

Whataworld:

how big a propane tank do you have?
or
how big a battery bank do you have?

Let me rephrase this: not literally unlimited hot water, but enough to enable me to take the 10-15 minute showers I am used to on land. This boat will be a liveaboard, and I would like to bring as many creature comforts along as I can!

[Doodles]

Originally Posted by WhataWorld!

Let me rephrase this: not literally unlimited hot water, but enough to enable me to take the 10-15 minute showers I am used to on land. This boat will be a liveaboard, and I would like to bring as many creature comforts along as I can!

Good luck ... I don't think its gonna happen!

But then how big is this cat?

[sarafina]

wow... never mind propane tank size...

how big is your WATER TANK?

And I am interested, how big is that Cat?

Shower heads flow 2.5 gallons per minute with a line feed pressure of 80 pounds per square inch. So you can do the math and figure what the water use will be...

[WhataWorld!]

Originally Posted by sarafina

how big is your WATER TANK?

And I am interested, how big is that Cat?

The water tank is 92 US gallons, and the cat size is 45 feet. So it should be doable with the 2.5 gpm flow rate.

[Doodles]

Originally Posted by WhataWorld!

The water tank is 92 US gallons, and the cat size is 45 feet. So it should be doable with the 2.5 gpm flow rate.

15 minutes @ 2.5 gpm = 40% of your 92 gallons ... you sure you want to do that?

[sarafina]

well if you can figure out how to keep the tanks all full there are a number of solutions for hot water. Depending on the engine some boats had a heat exchanger system that heats water from the engine. There are inline water heaters that use electricity, or propane.

This one is one of the few that meet your flow demand;

Precision Temp Boat Tankless Hot Water Heater. Gas Marine Water Heaters. Propane Boat Hot Water Heater

Here is some good info on how the systems needs to be set up.

Boat Plumbing by Don Casey

[Minggat]

I have also given this some thought.

We had a pool in the back yard when I was a teenager. My dad had some solar water heater panels installed on the roof of our garage that pool water was pumped directly through them after leaving the pool filter. He didn't use the pool himself, so he didn't experience how uncomfortably hot it was to swim in it for very long.

I Googled -Solar Water Heater Panels some time ago and learned that some inovators are using the principle with refrigeration tubing and collector boxes.

I was thinking I could install such a panel on top of my dodger and hopefully get the desired result.

Then I thought.... nah. I don't care that much.

[zopi]

hybrid...heat exchanger off the inboard, in some cleverly engineered combination with the solar option..I luvs me some solar...as long as it doesn't eat deck space...

[banyandah]

Easy.
Run the genset's cooling water through a coil inside an insulated tank. I've got a manufactured marine water heater that has one in addition to a AC element, and Presto, the water heats up as you make it.

[Doodles]

Originally Posted by Maren

Usually the problem is not an unlimited supply of hot water, but an unlimited supply of water.

But if he ways to take 37 gallon showers, this is the real problem.

[Kashmir cat]

Shouldn't be too big of a problem. My wife takes 10-15 minute showers on our boat. If you have a 10-12 gallon water heater or two 6 gallon water heaters like we have on our catamaran, we just turn up the thermostat on the water heaters to 160-180. ( If you run the engines for any length of time the water will be that hot anyway) This enables her to mix a very small amount of superheated water with a large amount of cold water to last 15 minutes at 105-110. You just want to be careful and not accidently scald yourself. You don't want to end up like that lady who spilled a 32 ounce supersized 180 degree cup of joe on her crotch at MacDonald's a few years back.

Also, with a 40 psi system, I don't think I get anywhere near 2.5 gpm, so even at full blast you shouldn't use more than 20 gallons a shower. LIVE IT UP! YOU ONLY GO AROUND ONCE IN LIFE!