Solar hot water

[sparrowhawk1]

I will probably never install one of these PV diverters, I'm happy heating up the water on my induction heater when I have excess electricity but for those that have large PV systems that go into float mode almost everyday something like this might be a worthwhile investment. Now I just did a quick Google search I'm sure if you took some time you can find an even better deal.http://solarimmersion.co.uk/

[sparrowhawk1]

this is from a PV company so take that into consideration. and I understand a boat doesn't have a lot of room so this may not work for a main supply of hot water but it's interesting and I thought I'd pass it along.http://web.archive.org/web/201306101...lar-hot-water/

[sparrowhawk1]

Pro Solar Direct video. https://youtu.be/HRV8iCDLADM

[SailingFan]

I have been considering this issue for some time, and have come to the conclusion that perhaps a single-solution approach is too much to expect for the liveaboard or even cruising couple.

I am thinking that perhaps I could offer another solution that could help as well on those cloudy days or when the boat is transiting during calmer seas using the motor. I do realize that someone has likely already made (or at least attempted) this alteration, but as I have not seen the multi-system approach really listed in this thread, I figured it worthwhile to mention...

I have an SB8 Yanmar diesel in my '78 Hunter 27, and it has a couple 5/8 inch water lines for cooling the engine then routing that saltwater to the exhaust line. I also have an admiral on board who wants a standup shower below-decks (yes I know), and the thought of a solar shower tank is very appealing to us both. I have already been considering the possibility of a flat tank strapped to the cabin top aft the mast, or possibly on a sun-facing side deck (preferable in my opinion), with a line run into the head port on that side and a sink sprayer on the end of that line. Still, there should be additional options for occasions when such is not as useful for whatever reason (to include bug intrusions, cold weather, etc.).

I am thinking that perhaps a simple and home made calorifier that uses the saltwater as it leaves the engine head and takes a minor detour through a coil around a metal line that pipes fresh water for showering or other uses then travels into the exhaust from that coil would be a good solution, and I am reasonably sure that some have used such an effort to make hot water, or at least warm water (as I heard that this used seawater would run about 185 degrees Fahrenheit, enough to heat cold water flow through a copper pipe the coil wrapped around, it seems reasonable that warm water could be generated pretty simply as long as the engine is running. The seawater line would have to be made of something that did not corrode away, so I am unsure of what that would be, especially when it is against copper line externally. This would be FAR less problematic in fresh water rivers though.

I suppose another method could be to run the metal line alongside the engine itself, without rerouting the cooling water line, and allow the engine to heat the fluid through radiant and conduction cooling from the warm metal to metal contact but I don't know if it would be possible to do and get efficient warming without causing other problems. I am new at this, after all.

I do understand that most of us who are (or want to be) sailing would rather not have the engine running every time we want a shower at anchor, but what the heck, some are running it for watermakers and power generation while moored, so why not make use of waste heat and get a fresh shower at the same time? At least the engine is already running, and the cooling water would be useful as it passed by...

Still, by the time I get this thing together, she will probably decide that she does not want to shower on board at all, so...



Incidentally, I have also been wondering if the same engine-running event could be advantaged to freeze some ice cubes or blocks with some sort of belt driven compressor (like the one on a car or in a freezer)?? Would such a tiny engine be able to do that, or am I just begging for more problems?

[SailingFan]

A church-mouse such as I could not afford this PV solution you guys are mentioning, but I wonder if it could be used to drive a watermaker from excess solar power as well as heating water in a thickly insulated tank that was used solely for hot water, when the regular water tanks are full? Would such a use be feasible and economical, given the expected cost of such a system versus other methods?

[RaymondR]

I have found that migrating with a climate which has one preferring cool water for showers is a much better solution?

[SailingFan]

Originally Posted by RaymondR

I have found that migrating with a climate which has one preferring cool water for showers is a much better solution?

Yes, I like this solution!

Only problem is that I want to do some traveling, hopping from one island to the next, then perhaps as skill development allows, make a trip across the tropics to Bermuda, then to the Azores, to Portugal, etc. It would be great if I had some method available of making that trip (and of mooring in Florida for much of the year) with capability of a warm shower for the missus. I could take cold showers, no problem. In the Navy it was not all that unusual, and the water smelled like jet fuel anyway. I don't think my new Admiral would put up with that. Replacing the Admiral is not an option, so I have to consider what the cost to warm the water would be. I sure don't want to spend more than I did on the boat to heat water for a daily shower for her... Call me cheap??

[Don C L]

Originally Posted by SailingFan

Y I don't think my new Admiral would put up with that. Replacing the Admiral is not an option, so I have to consider what the cost to warm the water would be. I sure don't want to spend more than I did on the boat to heat water for a daily shower for her... Call me cheap??

I am more curious how you will put in that stand up shower in your Hunter 27 than how the water will be heated! I am guessing a way to wall off the v-berth and the salon and drain to bilge, right? although I guess you do have some room up there. How's the headroom? Send photos!

[RaymondR]

Originally Posted by SailingFan

Yes, I like this solution!

Only problem is that I want to do some traveling, hopping from one island to the next, then perhaps as skill development allows, make a trip across the tropics to Bermuda, then to the Azores, to Portugal, etc. It would be great if I had some method available of making that trip (and of mooring in Florida for much of the year) with capability of a warm shower for the missus. I could take cold showers, no problem. In the Navy it was not all that unusual, and the water smelled like jet fuel anyway. I don't think my new Admiral would put up with that. Replacing the Admiral is not an option, so I have to consider what the cost to warm the water would be. I sure don't want to spend more than I did on the boat to heat water for a daily shower for her... Call me cheap??

Not cheap mate more like pragmatic. I have had women aboard and it vastly complicates pretty well any fresh water problem.

[SailingFan]

Well, there is just over 6' of headroom (which is great as I am two inches over 6 foot).

What I am thinking of is setting up a small tray under a slightly elevated false floor within the head. As the v berth is too far up from the deck to easily get into anyway, the slight additional step height thus created would allow that access to be easier and also allow me to install a small bilge pump in a plastic tray under that elevated platform (perhaps three inches could be enough, maybe even two could work if I locate the additional bilge pump to the side and run a hose to the tray). This would keep the human hair and skin cells out of the vessel's bilge, and prevent that smell of rotting human tissue from becoming a problem (while preventing the real bilge pump from getting bound and jammed by that detritus as well).

Then I am thinking I can arrange a shower curtain along an aluminum hoop mounted on the overhead, in the center of the head standing area (between the berth and the salon), and use velcro strips to seal the curtain closed when the "shower" is occupied. With care, the head can probably still be used while someone is in the shower, I suppose (there is very little privacy on a boat this size).

I can mount a shower head on a flexible hose and locate it on a hook mounted to the curtain support hoop, and she can use it for a Navy shower. We once lived on a remote mountain in a fifth wheel RV, so she is well familiar with the concept of water rationing, and understands what is involved in this form of bathing. Of course, it will only work well when on calm seas (aka likely at anchor, docked, or moored in calm waters).

The discharge line will need to either run over the side out a cabin window or perhaps into the lavatory sink. Alternatively, I do have a current through-hull that the toilet originally used, one I have not decided to hook back up because of regulations that did not exist when this vessel was built. At this point, I am unsure of the next step, because of this issue. The sink seems the best bet, however, directly followed by the discharge hose leading out the port and over the toe rail...

I can post pics tomorrow (will be back on board for more work).

[JimsCAL]

Originally Posted by SailingFan

What I am thinking of is setting up a small tray under a slightly elevated false floor within the head. As the v berth is too far up from the deck to easily get into anyway, the slight additional step height thus created would allow that access to be easier and also allow me to install a small bilge pump in a plastic tray under that elevated platform (perhaps three inches could be enough, maybe even two could work if I locate the additional bilge pump to the side and run a hose to the tray). This would keep the human hair and skin cells out of the vessel's bilge, and prevent that smell of rotting human tissue from becoming a problem (while preventing the real bilge pump from getting bound and jammed by that detritus as well).

This is way too complicated. Just install a shower drain pump.

[sparrowhawk1]

Yes install a sink drain that has a strainer basket, then have the hose go to accessible spot and put an inline strainer with a finer mesh, then have it go to a diaphragm type pump have the pump above the water line or have the hose go above the waterline preferably by at least a couple feet and then to a thru hull. Just turn the pump on whenever you're taking a shower.

[Franziska]

The discharge sounds a little to complicated to me.

This works absolutely fine for years on my boat:

Small compartment under shower with simple float switch.
It's actually just a bilge section under a floorboard.
Attached a simple diaphragm pump with a small valve to remove back flow. Its branched with a Y into the sink drain (which exists well above DWL).
No strainers needed.
No problems with smell or clogging from hairs (I have long hair).

Greywater discharge on older boats is allowed in Europe.

You might want to add a vented loop and seacock on a monohull.

www.ladyrover.com

[sparrowhawk1]

Well I can just say that that's a system I've used on the last two boats and I've had to clean the drain every 3 months and clean the strainer every 6 months so maybe your pump is able to pump it through but I haven't found that. And the sink drain part will start to whistle when it starts getting clogged and the mesh strainer you'll just notice lack of flow. Now back to heating water.
https://youtu.be/8bubFtRK6F8

[PEACETIME]

I have been using this water heater for at least 10 years. One thing I have changed is replacing the water pump that came with it, to a 12vdc boat pump. It is designed to use the small green LP bottles but I have a line I can connect to my 20lb tank which I use for cooking, heating, ect. It takes about 5 min to heat 3 - 4 gallons of water to shower temp. in the winter time. I can get about 10 showers per the 1lb green bottle. The plastic holding bucket has a cheep divert valve from the hardware store in the top. I have the pump circulating the water thru the heater hanging outside the cabin until the temp is reached then I shut down the heater and divert the heated water to the shower head. Nothing like a good hot or warm shower at the end of a day.