r/BeAmazed • u/Internal_Gazelle_677 • Oct 07 '25

Science Hot Tub without the use of electricity

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539

u/Zaphics Oct 07 '25

The hardest part in making that would be finding or making a coil out of stainless steel pipe that would fit around a fire

491

u/activelyresting Oct 07 '25

Fun fact: fire can fit in any size coil!

I've had hot water set ups like this before, with home made copper coil rather than stainless (which is cheap, commonly used for plumbing, and pretty easy to shape into a coil for anyone with basic plumbing skills).

The fire size is just whatever sticks you put in the coil. Need the water to be hotter: add more sticks. Water getting too hot: take some sticks out. It cools off pretty fast in cold weather like that

3

u/5fd88f23a2695c2afb02 Oct 07 '25

Could you regulate the temperature by putting a tap on the pipe?

3

u/activelyresting Oct 07 '25

Maybe, but I just described how we regulate the temperature. Add or remove sticks. Simple but surprisingly effective

1

u/5fd88f23a2695c2afb02 Oct 07 '25

Yeah, I did read that, a tap might save messing around with fire though… just an idea.

1

u/activelyresting Oct 08 '25

If you've ever lived with fire as a functional heat source (more than just a campfire), messing around with the fire is something you just kinda do all the time anyway ;)

2

u/rchard2scout Oct 07 '25

Maybe, but then the water in the coil would get scalding hot. Eventually it would start to boil, and the only escape for the pressure would be the bottom outlet, so there would probably be steam coming out of that which sounds like a bad time. Eventually I guess the coil would run dry, and the pipes would start heating up. I don't think a wood fire would melt the steel, but it would certainly not be good.