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
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
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