Source of hot water while cruising

[SVRocinante]

Originally Posted by CaptTom

Some really great ideas here, thanks all!

But back to the generator vs. mains thing. Put aside any debate about idling being "bad" for the engine. Maybe it is, maybe it isn't, but that's not the point.

The genset is smaller, and you're moving less iron around, so there's an efficiency angle. More importantly, just about all the energy it produces is turned into some kind of "work." A typical alternator, at idle, will take forever to charge up a decent-sized house bank. A genset and a good high-amp smart charger will do it much faster, which means shorter run time, which your anchorage neighbors will thank you for. It'll also heat up your water faster than an idling main. While it's running, you can use other 120V loads, from coffee maker to electric stove to hair dryer, whatever.

Finally, loading up the genset is supposed to be good for it.

When at anchor for more 24 hours, we run the genset maybe twice a day, 30 to 60 minutes each time, depending on battery SOC and what we want to do. It's not a perfect solution, it's not as environmentally friendly as solar, but it's already there and convenient.

Thanks! Was thinking along those lines myself... I actually have an adapter allowing me to plug my boats Shower power cord into my portable generator... works very nicely! The only downside is having to pull the darn generator out of the lazarette!

[SVRocinante]

Originally Posted by a64pilot

Engine not under a load, doesn’t generate much heat, it’s more “efficient” to run a generator.
Truckers regularly or used to anyway until the laws changed idle their trucks overnight and get a Million Miles out of an engine, but I bet that is mostly due to the fact that at the end of all those extended idles, was a day of being run hard.
Only very rarely did they spend the night in the truck, wake up and turn it off and go home.
Idling, even extended idling isn’t all that bad, as long as it’s followed by a good hard run before shutdown, where it’s bad is an extended idle, then a shutdown. That can glaze cylinders.

Thank you!

[SVRocinante]

Originally Posted by noelex 77

This is a good solution for many, but does not work well for us.

We usually stay at anchor in the one location for several days, sometimes a week. We use solar power so do not need to run the engine or generator for power. When we move we usually use the engine very little. So for many days the water would be cold unless we deliberately just ran the engine for hot water.
...

Sounds exactly like our use model! Except, we’ve been known to stay at one anchorage for almost 3 weeks! Our blackwater holding tank being the limiting factor!

[SVRocinante]

Originally Posted by boatpoker

Standard Seaward 11g. water heater - boxed in 4" of blue foam board insulation - hot water for four-five days at anchor.

Added to my list of potential solutions - Thank you!

[SVRocinante]

Originally Posted by Paul L

It's always interesting to hear what creature comforts are desired by different cruisers for comfort. As long term cruiser we don't look at it like camping or even glamping. This where we live and there's plenty of daily discomforts to make up for any luxury living we might add to the boat.
When we decided we wanted to add an efficient heater to the boat before wintering over in cooler climes I wanted to not use up a lot of space and wanted to get hot shower water too. We went with a Hurrican Zephyr heater. This diesel heater heats the boat via a couple of radiators during the winter and provides on-demand hot water all year round. It fit in the place of our old tank calorifier. Not cheap, but one of the best upgrades we've made.

Thanks Paul - will have to look into it... might be a good replacement for my Webasto when the time comes.

[boatpoker]

Originally Posted by a64pilot

Engine not under a load, doesn’t generate much heat, it’s more “efficient” to run a generator.
Truckers regularly or used to anyway until the laws changed idle their trucks overnight and get a Million Miles out of an engine, but I bet that is mostly due to the fact that at the end of all those extended idles, was a day of being run hard.
Only very rarely did they spend the night in the truck, wake up and turn it off and go home.
Idling, even extended idling isn’t all that bad, as long as it’s followed by a good hard run before shutdown, where it’s bad is an extended idle, then a shutdown. That can glaze cylinders.

+1 ..... too short

[Jim Cate]

What I think is a safe installation of a Paloma LPG flash heater, used solely for showering.

1. Local gas shut off valve, in closed position except when showering.

2. 3" vent line directly through the deck to a mushroom vent.

3. ventilation fan ducting cabin air into shower compartment any time power is on to the pressure pump for the shower.

4. Small port open to the outside air whilst showering.

5. Auto shut off if pilot goes out. Pilot only on whilst showering anyway.

It may not meet some arbitrary standards meant for folks who are not by nature careful, but I believe that it is quite safe in our hands. Has been in use for the 15 years we've been living aboard whilst cruising in this boat.

Jim

[boatpoker]

Originally Posted by Jim Cate

What I think is a safe installation of a Paloma LPG flash heater, used solely for showering.

1. Local gas shut off valve, in closed position except when showering.

2. 3" vent line directly through the deck to a mushroom vent.

3. ventilation fan ducting cabin air into shower compartment any time power is on to the pressure pump for the shower.

4. Small port open to the outside air whilst showering.

5. Auto shut off if pilot goes out. Pilot only on whilst showering anyway.

It may not meet some arbitrary standards meant for folks who are not by nature careful, but I believe that it is quite safe in our hands. Has been in use for the 15 years we've been living aboard whilst cruising in this boat.

Jim

The Paloma manual says .....

[charris]

On demand propane fired hw heater such as Paloma, Bosch etc. Various brands now, very efficient, all the hot water you want (so long as you have propane)

[Jim Cate]

Originally Posted by boatpoker

The Paloma manual says .....

Well, isn't that special! I know that you are a stickler for regs and manuals and the ABYC... but can you point out where I am at risk in my installation?

Paloma's lawyers have directed them to CTA I reckon, but they don't back up those recommendations with reasons.

So, again, can you show me where I am at risk, seriously?

Jim

[Fore and Aft]

Jim I survey plenty of boats here in Oz that have Bosch instant hot water gas systems on board. They are always mounted outside and I have never heard of anyone having any problems?
Cheers

[Jim Cate]

Originally Posted by Fore and Aft

Jim I survey plenty of boats here in Oz that have Bosch instant hot water gas systems on board. They are always mounted outside and I have never heard of anyone having any problems?
Cheers

Thanks for that! But it does not truly apply to my application, which is "indoors", but with positive ventilation and venting. "Outdoors" does not work well on sailing vessels in general... there is certainly no such location on Insatiable II that would be free from occasional green water!

Jim

[Dockhead]

Originally Posted by Jim Cate

Thanks for that! But it does not truly apply to my application, which is "indoors", but with positive ventilation and venting. "Outdoors" does not work well on sailing vessels in general... there is certainly no such location on Insatiable II that would be free from occasional green water!

Jim

The two different risks are CO, on the one hand, and leaking propane and explosion, on the other. With enough ventilation, and with the combustion products properly vented outside, you've surely dealt with the first one. But the second one is much trickier.


I don't like propane on boats in general, but I guess a heater like this might be ok (ignoring the regs), if it were mounted outside the cabin where leaking gas can't drain into the interior, or mounted inside with a sealed burner and really good installation of the gas line (separate line all the way to the regulator, free of joints to the extent possible). And with a solenoid to shut it off at the regulator (not inside the cabin). Even then, there would be a certain risk which I would not be keen to take. With less than that, in my opinion the risk isn't really acceptable.




Getting back to the OP's question -- there are a plethora of different ways to produce hot water, well explained in this thread. None of them with the risks associated with propane.


These can be combined in different ways. I know a boat which has a calorifier heated by a small, dedicated hydronic heater (in addition to engine waste heat and immersion heater). Not the cheapest way to make hot water, but totally safe and simple in operation. By the time you go to the trouble to make a propane system really safe, you will have probably spent as much money as one of these would cost.



And if you're going to install a hydronic heater, you can heat the boat with it as well.



On my boat, I have three methods: (a) hydronic heating system; (b) engine waste heat; (c) 1500 watt electrical heating element from shore power or generator or even alternator and inverter.


I love Noelex's shower mixer tank -- ingenious and valuable and a great, simple substitute for a calorifier on boats which won't get much use from engine waste heat. But for boats that use their engines much, a calorifier is a really great thing to have. You arrive in your anchorage or harbour with a tank full of hot water, even if you only motored for a little while to manuever into the harbour. And that just when you most want a shower. Calorifier is a great thing for most boats.




Not discussed here so far is the parallel question of heating the heads compartment itself. I spent some time on a large Swan which had a sauna system installed in one of the showers. That was great! In cold weather (and I spent the summer in the Arctic), I like to get the heads compartment really warm before doing my ablutions routine, so I run the generator and turn on a 2200 watt electric heater closed up in the heads, or turn on the hydronic heater, or both. This is not only for comfort, but to dry out the space -- and if you don't think about this, you can put an unpleasant quantity of moisture into the interior of the boat by taking a shower in cold weather. My next boat will have underfloor heat in the heads, or some way of individually superheating the heads.

[oldtom]

Originally Posted by SVRocinante

Thanks kenomac, atmartin & nautical62

Considered using my portable generator vs engine not sure which is more “efficient” that’s one of the reasons i was asking what others do.

Considered the solar shower, but didn’t think it would retain the heat from the previous day... does it?

Yep, could heat up water on the stovetop...

Cruising the Bahamas sounds like a good solution!

Plum a heat excharger in the engine cooling system the engine can heat the water in the storage tank same as the heater in you car or make one up to use the exhaust from your genset .

[boatpoker]

Originally Posted by Jim Cate

Well, isn't that special! I know that you are a stickler for regs and manuals and the ABYC... but can you point out where I am at risk in my installation?

Paloma's lawyers have directed them to CTA I reckon, but they don't back up those recommendations with reasons.

So, again, can you show me where I am at risk, seriously?

Jim

Suggest you re-read my posts. I never said it was unsafe. I left that up to the people that designed and manufactured your unit.