heating water for bucket shower

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(Apologies for repost, I had put this in the forum for heating but this is more of a cooking stove type)

Hi rocket-people,

I am new in the forum and on the rocket stove world. Still starting to look at solutions for heating water for shower on an off-grid site where I will camp with a group of 5 people.
The goal is to heat water for an outdoors bucket shower, meaning i need 15 L of "hot" water for one shower. Apparently the ideal temperature for showering is around 45ºC.

What do you think is better: A) to heat 15L at a time up to 50ºC and then transfer the water for the bucket in the shower, or B) to boil 5L of water (100ºC) and add 10L of cold water (15ºC). It really is feasible to transport the 15L from the place where the stove will be, to where the bucket is. I would intuitively think A is better because there should be more heat losses after some point in solution B? Am I wrong?

And regarding expectations about time? I didn't find so much info around. In this post the author mentions it takes 25 minutes to boil 5L of water. Is there any other posts you recommend me to read? Any spreadsheet around that could be useful for me?

Honestly I would appreciate a lower time for taking all the showers. Assuming solutions A and B would take the same amount of time, I would need 2.5 hours to take 5 showers. So I saw a third, more complex possibility: C) something like www.youtube.com/watch?v=B9BQGamXLMk. They mention that heating about 120 liters of water would take 2 hours and would allow 10 showers. My question is whether heating water for 5 showers would take half of that time or is there any scale issue? Could I assume that when heating water only for one bucket shower it will take roughly 1/10 of the 2h?

(Plus solution B would allow me use the same stove to cook soup as well. I know I am mixing apples with oranges, but it is more simple and versatile, right?)



Thanks!
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[pigbuttons]

I think if you watch this video you can get the idea of just how efficiently hot water can be produced. I hope this helps.

Aprovecho stove factory

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Hi pigbuttons,

That's a great video, thanks! However it is oversized for my case and does not respond to my questions above.

Cheers,

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[pigbuttons]

As far as option C) I've seen many youtube videos of the copper coil type water heaters; I even took the bait and built one. I've never seen one that truly works as advertised. Never. What I mean by that is a video that starts with cold water and through thermosiphon through coils proves a reasonable heat time for a quantity of water. Plus all of that piping exposed without significant insulation would drop the temperature gained in the stove on the trip to storage. That's why I put a truly successful method video above. Those guys have been researching the whole water heating technology for decades. You don't have to make one that large, but the technique is solid science.

As far as A) and B). For me it would depend on what equipment or buckets you have to heat in, and carry with. In practical terms it is easier and quicker to heat 5L than 15L.

[pote]

Thanks again for the input. I agree C is top complex and prone to technical difficulties you mention. As for A vs B, note that i Said heating 15L to 50°C vs heating 5L at 100°C. I havent thought about material, but for sale of simplicity let's say I would transfer the water to the same Bucket shower.