[HowToLou] got back to basics instead, with his simple wood-fired water heater design ... If you’re looking for a hot shower from your outdoor wood stove, a build like this might be just ...

For the purpose of making a hot tub, any style can suffice. The process of insulating will need to be adjusted if you go with a ridge free tub. To heat the water, we used a wood-fired thermosyphon ...