Water heater using solar (not the camping bag)

[tgoodall]

We're looking into adding a solar water heater. Sailing in Maine has been great, though taking showers have been...(brutally...) cold. The thought of running the engine just to get a little hot water is not very appealing. We researched two solar add-on options to generate hot water with the goal of not having to modify the entire system and we're wondering if anyone has any experience with these or other options.

Solar Water Heating System - Â* Â* Â*Custom Marine Products - Marine Solar Systems

http://www.heliatos.info/instructions/RHSystem.pdf

[sailorchic34]

I'm not a big fan of heating water on the back of a solar panel. Better for air to circulate under the panels. High panel temperature will cause reduced voltage output due to the panel temperature coefficient thingy. Plus once the water heater is hot, the water under no flow conditions would get hotter still, with negative impact to PV output.

For a boat that is not used in freezing conditions I would dump the braised plate heat exchanger and second pump. Just add drain down for winter.

For a typical 6 gallon marine water heater a solar hot water panel of approximately 5 SF of panel area would be adequate to heat the tank up in the peak sunny days. Perhaps 7 SF in maine.

[Chris66]

Whilst not familiar with any solar hot water heaters, i did bump into the guy who owns this company Home - Copperhead Water Heaters and it sounded interesting.

[GordMay]

Greetings and welcome aboard the CF, Tammy.

[Dymaxion]

Check into the $150 propane instant HW heaters. Bring a CW line with quick disconnect out to the cockpit, connect to heater mounted outside, and have another line heading back to your shower inside or just use the handheld shower nozzle and shower in the cockpit. They are water efficient in that they only heat when water flows through them, the handheld part has on off button so you can wet/lather/rinse with minimal flow. Mine has automatic ignition via 2 D cell batteries. You could mount it inside the boat, perhaps on bulkhead above galley area BUT they are open vented, not via an exhaust pipe. Plus it's a potential propane leak. You would introduce extra humidity from the exhaust, scorching heat directly above it, and suffocate from lack of oxygen or CO poison. But you'd die clean and refreshed...You could also mount it on a sturdy chartplotter bracket that let it swing out into the cockpit for use.... I'd just hang it off a stern rail myself.

[newhaul]

Originally Posted by Dymaxion

Check into the $150 propane instant HW heaters. Bring a CW line with quick disconnect out to the cockpit, connect to heater mounted outside, and have another line heading back to your shower inside or just use the handheld shower nozzle and shower in the cockpit. They are water efficient in that they only heat when water flows through them, the handheld part has on off button so you can wet/lather/rinse with minimal flow. Mine has automatic ignition via 2 D cell batteries. You could mount it inside the boat, perhaps on bulkhead above galley area BUT they are open vented, not via an exhaust pipe. Plus it's a potential propane leak. You would introduce extra humidity from the exhaust, scorching heat directly above it, and suffocate from lack of oxygen or CO poison. But you'd die clean and refreshed...You could also mount it on a sturdy chartplotter bracket that let it swing out into the cockpit for use.... I'd just hang it off a stern rail myself.

While I agree with about everything I have to put this in for people to see. As far as humidity added it comes up to 1 ounce per hour per thousand BTU. For propane

[Pizzazz]

Originally Posted by Dymaxion

Check into the $150 propane instant HW heaters. Bring a CW line with quick disconnect out to the cockpit, connect to heater mounted outside, and have another line heading back to your shower inside or just use the handheld shower nozzle and shower in the cockpit. They are water efficient in that they only heat when water flows through them, the handheld part has on off button so you can wet/lather/rinse with minimal flow. Mine has automatic ignition via 2 D cell batteries. You could mount it inside the boat, perhaps on bulkhead above galley area BUT they are open vented, not via an exhaust pipe. Plus it's a potential propane leak. You would introduce extra humidity from the exhaust, scorching heat directly above it, and suffocate from lack of oxygen or CO poison. But you'd die clean and refreshed...You could also mount it on a sturdy chartplotter bracket that let it swing out into the cockpit for use.... I'd just hang it off a stern rail myself.

I had not paid attention to these heaters before. Curious if they could be used as a hydronic heater for the boat. I am thinking, mount it in the cockpit, next to the grill, drive water via a 1.5 GPM pump, then have a blower in the cabin. May be they have dedicated units for this purpose. Is it silent? Auto start? I will check into it.

[GulfportBarb]

We used this propane hot water heater when we lived off the grid on land. I am not sure how well it would hold up on salt water, but it is small enough you could put it on a bracket in the cockpit when you need it and stow it the rest of the time. You do need decent water pressure for it to work so you may want to replace your water pump with a higher pressure one. For just over $100 at Home Depot:

The Eccotemp L5 Portable Tankless Water Heater is the original and best selling portable water heater on the market today. You get instant, endless hot water wherever you are. The Eccotemp L5 portable tankless water heater is perfect for campsites, cabins or simply around the house. Wash your car, wash your boat, take a hot shower, and wash the dogs or the horse. You can add the Eccotemp L5 portable water heater to a pressure washer for an even better cleaning. The ignition is with 2 "D" cell batteries so it makes it great for off grid or other areas where electricity is not readily available. The ideal operating range for the Eccotemp L5 portable tankless water heater is 20 80 psi. The system also works great on modified water systems such as a 12-Volt pump. Total dimensions are 14.5 in. H, 11.5 in. W, 4.5 in. D and weighs 13.8 lbs. This unit requires a 2 in. clearance from a wall, 1 ft. side to side from anything flammable, 3 ft. from a window as well from an overhang and 18 in. from the ground. The L5 will offer a 30 to 35° rise at 1.5 GPM (gallons per minute).

20 minute automatic safety shutoff timer
On/off shower head included
Battery igniter means no electricity needed
Includes CSA regulator for use with standard 20 lbs. grill propane tank
Can be used portable or wall mounted
37,500 BTU
1 year manufacturer warranty on the unit
Rated voltage: 3-Volt (D-cell batteries)
Not for use with a bilge pump
Manual water temperature controls
Garden hose adapter included
Rated gas pressure: 11 in. of water column
Rated heat input: 11 kW
Click here to check out our buying guide on water heaters

[Junk Viking]

Running hot water is an enormous energy drain.

Why not just warm up exactly the amount of hot water you need and use it?
Use a Pump-up Solar Shower warmed in the sun in the summer and on the stove in the winter.

You can even have two to save water:
- Hot saltwater
- Hot sweet water


Example: Duck Works Pump-up Solar Shower

[zboss]

Originally Posted by tgoodall

We're looking into adding a solar water heater. Sailing in Maine has been great, though taking showers have been...(brutally...) cold. The thought of running the engine just to get a little hot water is not very appealing. We researched two solar add-on options to generate hot water with the goal of not having to modify the entire system and we're wondering if anyone has any experience with these or other options.

Solar Water Heating System - Â* Â* Â*Custom Marine Products - Marine Solar Systems

http://www.heliatos.info/instructions/RHSystem.pdf

THat second system looks appealing... its purpose built instead of using the back of a PV panel. You could make your own.

[nwdiver]

Have a friend with a black painter beer keg on deck, gravity feed into his head, it has a tiny 12 volt pump to fill it, works after a day of sun in the PNW.......


Me I have a demand propane heater........I guess the are not legal in the USA but were installed in hundreds of Canadian built boats.........never heard of one blowing up as is always reported on this site...........

[Emouchet]

You may want to look at a diversion load controller:
The device takes out a bit of the power delivered by the solar panel and can feed the water heater resistor with electricity:

https://www.emarineinc.com/categorie...ad-Controllers

You may need to change the resistor in the water heater to be 12v compatible.

[travellerw]

We run our 5 gallon hot water heater off our inverter on sunny days.

30 min of running provides us with enough "hotish" water for 2 showers. Its a 600W element in a 5 gallon water heater.

[kenbo]

I've sailed on a friend's boat that had 2 Heliatos panels on his radar arch. They worked great but I remember him saying something about he trouble controlling the direction of the water flow until he installed two "monoflow tees" where the panel's lines went into the HW tank.

It was a very efficient set up. Heating water with a 12V element is not so efficient.

[Lepke]

I've had solar water heaters on land, but don't think their worth the space on a boat. I've used the bag showers as a diver and with a small boat that would be worthwhile. Otherwise you need a fairly big collector and plenty of sun. Collector space would be better used for solar cells.