Hot water tank for liveaboard

[hamburking]

Originally Posted by Stu Jackson

Paul,

30 litres is about 8 gallons. Tanks come in 6 and 11 gallon sizes.

Gallons are a regional unit, that vary in size by location. It was very sensible of the OP to use litres, which are the same volume worldwide...with only a variation in spelling based on location.

[hamburking]

I had a Hunter Legend 35.5 with stand up shower stall and a 6gal heater off the yanmar. If the heater was plugged into shore power, we never ran out of hot water. Most likely because the shower had a limited flow of water. This saved fresh water and conserved hot water. It was a pleasure to have a real shower on the boat. Although I always preferred the stern shower. I confess I might have been showing off a bit at my marina, especially to the parade of boaters marching down the dock with their towels and toilet bags in hand to the terrible showers ashore...Kingston's Confederation basin marina is famous for both the terrible shore-heads and the terrible marina design which all but assures dock crashes on a daily basis.

Perhaps the solution you are looking for is not a bigger hot water tank, but a more conservative shower head?

[Pizzazz]

I have a 6 gallon hot water tank. When on shore power, the thermostat keeps it at 120F. When running the engine the temperature goes up to 170F. It provides enough hot water for about a 20-30 min shower depending on how cold it is. If the engine is running we never run out of hot water. I would go with the smaller tank if your boat is below 35 feet.

[GRIT]

Unlimited hot water, with engine, and another with shorepower. That's good news. We had an instant hot water heater, propane, and it obviously gave an unlimited amount of hot water. But I'm gladdened that you both have such good experiences with your tanks, since that's the route we're taking this time.

The boat is a 15m catamaran, we have 400l of water available for showering, more or less.


And now we all know that hamberking is an exhibitionist!

I'm not sure, if I showered off my stern platform, if it could be called "showing off"!

As to bigger tank, or smaller head... I'm pretty sure that bigger is indeed better. YMMV

Thanks guys, for your contributions.

Paul.

[GRIT]

Is this your marina? Very nice from the air!

Paul.

[a64pilot]

My opinion is if it’s available, heating water electrically is superior to doing it with the engine, unless of course the engine is running anyway, but if I understand what your suggesting, it’s to run the engine daily to heat water for her shower, every day?
I have never run the engine just to heat water, but would suspect that without the engine being up to cruise RPM and under a load that it would take a long time.
Am I misunderstanding?

[GRIT]

Thanks A64 for your response.

I'm heating the water with a 5 kw hydronic heater, from Espar. The plan is to run it in the morning, before we wake up, and during her shower.

No wasted diesel, or engine wear, or noise...
Cheers.
Paul.

[john61ct]

For some reason OP was choosing to call this

> a 5kw hydronic heater

an "engine"

[GRIT]

I see I posted Brockville marina. Obviously the wrong marina.
Apologies.

Paul.

[a64pilot]

Originally Posted by john61ct

For some reason OP was choosing to call this

> a 5kw hydronic heater

an "engine"

OK, got it. Could be a translation issue, maybe.

[GRIT]

Yes, that was meant to relate the fact that most use an "engine" for heating water through a heat exchanger, whereas I'm using a diesel hydronic heater through a heat exchanger. My apologies for the confusion.

Cheers, and thanks for your participation.

Paul.

[Julian Alcorso]

Originally Posted by svquintana

We'll be launching our boat in the fall, and are finalizing some our equipment choices.

My wife works in an office, and she's going to want nice hot showers before work. We'll have a 5kw hydronic heater, which will run before and during her shower. So she'll be starting with a fully heated tank.

So my question is this: For those of you with experience using heat exchanger equipped hot water tanks (calorifiers), how large a tank would a person need to have a 10 minute "hot" shower, while the "engine" is running? A 10 minute shower equates to about 30 litres of water.

I can speculate, and calculate, all on my own; so I'd appreciate hearing from those with actual experience, rather than those who would like to guesstimate.

Thanks.
Paul.

Hi Paul, perhaps I am being 'dumb' but I do not understand why anyone would have a hot water tank??? I goy rid of the ones on my boat and installed an instant gas hot water system which means that I have as much hot water as I want (provided I've topped up my fresh water tanks!) without having to store it in a seperate tank.
I use 9kg gas (LPG) cylinders which last about a month with two or three people on board.
I dont have to run engines, heat exchangers or anything else for that matter. Just turn on the tap, the freshwater pump kicks in and I have hot water!
Not sure where you would position the instant gas unit on a smaller vessel but they are now available as quite compact units.
Just saying........................

[CaptTom]

Originally Posted by Julian Alcorso

Hi Paul, perhaps I am being 'dumb' but I do not understand why anyone would have a hot water tank???

Not dumb at all. Just a different opinion.

Personally, I hate tankless heaters. I have my reasons, but I'm not going to start a religious war over why. Let's just agree that there are valid opinions on both sides. Use what works best for you!

[GRIT]

Julian. If you'd care to read the thread from the beginning, all your questions will be answered. ☺
Just saying...��

To elaborate on our choice to stay away from propane, for water heating, this time. We found that propane fittings are not standard worldwide, while diesel is standardized (mostly).
So the fewer appliances we have to run on propane, the better. There are workarounds for filling tanks, but I'd rather not have to do that any more often than necessary.

Your 9 kg lasts about a month, my 750l of diesel should handily beat that figure.

Cheers.
Paul.

[GRIT]

Capt Tom.

Well said.

Cheers.
Paul.