So to take a shower for four people comfortable, it will be 1.9 kwh, which is a bit more energy than I thought. Instead of two 6v golf cart battery, nearly four would be needed, with enough left over energy to run some LEDs and the TV, but not the electric fan for the propane heater.
One note on the 600W 12V heaters- they may not actually exist. I saw a review of the elements that are sold on Amazon, and the resistance of the unit is not correct for 600W @12V.
Sailboat solution: $13 at a bigbox, paint it black leave it out in the sun... spray to wet, soap, spray to rinse (also conserves water
).
Theory:
| In practice, cold water will heat up fairly quickly, but then it slows down. Left out all day it can be quite warm. Downside is that it must be full for maximum heat (an air bubble at the top acts as an insulator). Mine stands upright next to the mast, so not horribly efficient. But hey, I'm roughing it. Hmmm, I suppose you could build a concentric cradle for it with reflective mylar (space blanket). That would would heat it from the bottom so it wouldn't need to be full and increase the area. Could also double as a cooking stove. |  |
I'm not seeing that (this listing?). The only negative reviews are without any detail, obviously clueless people (this isn't a part you want should get you really know what you're doing), and a guy complaining about the wiring (a valid concern, the terminals are very close, but I can live with it).
Would that be this same element? Seem legit to you? (thanks for the details of you're little box BTW, it's awesome to see)
That's what we used while we camped out of our minivan. It does work, but this build is the output of what we learned from those experiences (a good bathroom/water/shower setup is a must for my wife or she's just not interested in going).
I looked at this a long time and concluded the water wouldn't be hot enough. Are you aware of anyone making that work?For on demand heating with a hydronic unit, you don't need a water tank. Instead a plate heat exchanger and a tempering valve can provide on demand water heating.
Yes, that looks exactly like the one I ordered from Aliexpress, it even has the same brand name:
Many, the Rixen system is a common one.
this is the video where the resistance is measured, questioning the output ability-
freeds.es
That was a 800w unit he got off ebay and looks like it was maybe the incorrect item (for 48v?), he said he'd try the 600w version (which looks to be the same as the amazon one). He also said the seller said that one is known good, but he hasn't updated his findings yet.
That looks fancy. I'm not expecting much in the way of surplus solar in this build, but we are house shopping and want a pool ?
Interesting. I think I'd still want a very small dc hot water tank for the quick washing of feet and whatnot so I don't always have to run the coolant heater or engine... You know what, I have enough custom stuff to do on this build, I'm just going to go with one of those premade solutions and be done with it. It sounds like that's what you did and are happy with it.
