Hot water and hot air

[GILow]

Originally Posted by Dockhead

.Storing heat is a great idea -- not just solar heat from day time, but imagine how much heat you could pull out of main engine waste heat while motoring.
.

In my case I get bugger all heat from my engine because I tend to run it just to come and go from the pen. I get the impression that others use their engines a lot more than I do.

[Dockhead]

Originally Posted by GILow

In my case I get bugger all heat from my engine because I tend to run it just to come and go from the pen. I get the impression that others use their engines a lot more than I do.

Yes -- literally a case of YMMV.


Most cruisers, especially long-distance cruisers, use their motors, at least in addition to sails, for more than 50% of the miles they make. Some much more than that.

[RaymondR]

Originally Posted by Dockhead

Yes -- literally a case of YMMV.


Most cruisers, especially long-distance cruisers, use their motors, at least in addition to sails, for more than 50% of the miles they make. Some much more than that.

My boat has a hot water system with both AC and Main engine heating and I am a full time live aboard and coastal cruiser.

Biggest problem is that the pattern of my cruising is shortish voyages interspersed with weeks or months of anchoring wherein I have neither main engine use nor shore power and hence no hot water heating.

Since my cruising schedule is structured around a need to remain withing a 20 -30 degree C (68 - 86 degree F) temperature band I don't need space heating however there are limes when I would like air conditioning.

Two solutions I have considered are: A small gas engine driven battery charging unit with a water heating sleeve on the exhaust, I would then be able to heat water from waste heat whilst using my inverter to assist through the AC mains heater, And, a system of solar hot water absorption plates mounted beside my solar panels.

If the evolution of the cosmos hadn't created water we'ed have had to invent it, it having so wonderful thermodynamic properties.

[wingssail]

Originally Posted by RaymondR

My boat has a hot water system with both AC and Main engine heating and I am a full time live aboard and coastal cruiser.

Biggest problem is that the pattern of my cruising is shortish voyages interspersed with weeks or months of anchoring wherein I have neither main engine use nor shore power and hence no hot water heating.

Since my cruising schedule is structured around a need to remain withing a 20 -30 degree C (68 - 86 degree F) temperature band I don't need space heating however there are limes when I would like air conditioning.

Two solutions I have considered are: A small gas engine driven battery charging unit with a water heating sleeve on the exhaust, I would then be able to heat water from waste heat whilst using my inverter to assist through the AC mains heater, And, a system of solar hot water absorption plates mounted beside my solar panels.

If the evolution of the cosmos hadn't created water we'ed have had to invent it, it having so wonderful thermodynamic properties.

Your usage is similar to ours. So, in-case you have not seen the option already in this thread (a few times), consider a propane powered instant water heater. If you already have propane for your cooking then you are used to the fuel and it's limitations and dangers. If you fear propane, then it is not an option for you.

We've found them to be cheap and reliable and have used them for 33 years.

[cj88]

Originally Posted by RaymondR

Two solutions I have considered are: A small gas engine driven battery charging unit with a water heating sleeve on the exhaust, I would then be able to heat water from waste heat whilst using my inverter to assist through the AC mains heater, And, a system of solar hot water absorption plates mounted beside my solar panels.

Have you looked at Custom Marine Products and Heliatos solar water heating options?

https://www.custommarineproducts.com...ng-system.html

Heliatos Solar

[pbmaise]

Originally Posted by wingssail

Your usage is similar to ours. So, in-case you have not seen the option already in this thread (a few times), consider a propane powered instant water heater. If you already have propane for your cooking then you are used to the fuel and it's limitations and dangers. If you fear propane, then it is not an option for you.

We've found them to be cheap and reliable and have used them for 33 years.

That type of device was the first I removed after I purchased my vessel. The previous owners mounted it right next to a bunk in a room with very little ventilation. Having something burn propane less than two feet from a crew member didn't sit well with me.

I found a 48V DC powered air source water heater designed to hear water and heat a home. In my case I was exploring the idea of using this to cool my boat. The output of the device was the cool air it generated while heating water.

The unit I was looking at was made in China with European engineering.

The device could have been mounted on my deck behind the mast under the boom within a small "dog house". It was going to draw warm air from the vessel to heat water which I really didn't want so it was going to in turn cooled by sea water.

I'm the case of the OP this device could provide summer cooling, domestic hot water, and winter heating.

I was going to power it using solar and was thinking of battery backup.

On a small catamaran finding a deck space which won't get wet by seawater might be an issue.

[RaymondR]

Originally Posted by wingssail

Your usage is similar to ours. So, in-case you have not seen the option already in this thread (a few times), consider a propane powered instant water heater. If you already have propane for your cooking then you are used to the fuel and it's limitations and dangers. If you fear propane, then it is not an option for you.

We've found them to be cheap and reliable and have used them for 33 years.

I have one of those things I bought years ago and still in the box in a storage locker. By the time I got around to buying it I had been bathing in the cockpit out of a bucket heated on the stove and had become accustomed to it and never got around to rigging the gas heater up.

Being a cheap bugger and also fairly lazy I suspect that being able to heat the water on the stove to exactly the temperature I wanted to bathe in used only the minimal amount of gas required and the post bathe clean up only required a quick sluice of sea water from over the side with the same bucket.

[RaymondR]

Originally Posted by cj88

Have you looked at Custom Marine Products and Heliatos solar water heating options?

https://www.custommarineproducts.com...ng-system.html

Heliatos Solar

That also looks like an option but having left the spaces besides and between the panels when I remounted and expanded them I will probably stay with the original collector scheme.

Anyone out there done a copper in glass or acrylic, DIY vacuum tube collector.

[Dockhead]

Originally Posted by RaymondR

My boat has a hot water system with both AC and Main engine heating and I am a full time live aboard and coastal cruiser.

Biggest problem is that the pattern of my cruising is shortish voyages interspersed with weeks or months of anchoring wherein I have neither main engine use nor shore power and hence no hot water heating.

Since my cruising schedule is structured around a need to remain withing a 20 -30 degree C (68 - 86 degree F) temperature band I don't need space heating however there are limes when I would like air conditioning.

Two solutions I have considered are: A small gas engine driven battery charging unit with a water heating sleeve on the exhaust, I would then be able to heat water from waste heat whilst using my inverter to assist through the AC mains heater, And, a system of solar hot water absorption plates mounted beside my solar panels.

If the evolution of the cosmos hadn't created water we'ed have had to invent it, it having so wonderful thermodynamic properties.

Your first solution -- co-generation -- is basically the idea behind the WhisperGen, which sadly is no longer produced for yachts.


It's a small very silent Sterling engine powered by diesel fuel which produces a small charging current -- about 800 watts IIRC -- plus a lot of heat. An absolutely fantastic device for a use case like yours, especially in a cold climate. I would give an eye tooth for one of those.


As it is, my solution is an Eberspacher hydronic furnace. It does the job, but it's so inefficient compared to co-generation.

[Dockhead]

Originally Posted by wingssail

Your usage is similar to ours. So, in-case you have not seen the option already in this thread (a few times), consider a propane powered instant water heater. If you already have propane for your cooking then you are used to the fuel and it's limitations and dangers. If you fear propane, then it is not an option for you.

We've found them to be cheap and reliable and have used them for 33 years.

I think this has been discussed, but anyone using such a device should follow ABYC and mount it outside the passenger volume.


Not mounting it outside the passenger volume in violation of ABYC, and then compounding that error by doing so and relying on the 19 cent valves and 2 cent springs and other mechanisms from those cheap Walmart-grade Chinese devices to keep explosive gas out of the passenger volume of a vehicle in constant motion and in the marine environment -- cheap Chinese devices not designed to last long even in non-marine environments and not designed to be used in a moving vehicle -- seems like sheer madness to me.



Being economical is fine -- we all have to economize here and there -- but is your life and the life of your loved ones not worth the price of a $500 diesel heater? And what about your insurance?


/rant mode off

[GILow]

^^^^^ What he said! ^^^^^