Our outdoor bathtub journey
A few years ago, we significantly downsized in preparation of creating an efficiently running place to retire. In the downsizing, I lost room for my bathtub. For the most part showers are the best, but there are just those times that a shower just is not satisfactory, and you just want to soak. We also had an outdoor hot tub at our previous house, which I LOVED! Sitting outside under the stars and just relaxing in the hot water enjoying the night air and sounds is the best.
The hot tub has 2 major drawbacks though. The main one was chemicals. The more I researched the more I learned of the incredible damage chlorine and bromine does to our entire bodies systems. The second, cost. It was a constant expense to keep it regulated with chemicals and heated, especially during the winter, which is when it's the best. Our primary goals here have been centered around less expense and less chemicals, so this project was not feasible. Or was it?
In my journey of learning I saw an idea of an outdoor bathtub. Eureka! That could work! New water always used, so no chemicals to maintain and no cost outside of the hot water constantly being heated. So, I set out researching more... how could we heat it without electricity or expense? I dove into searching this topic, From YouTube videos to books and articles and yep even face book groups. I ask, I gather, I think! I then take the best of the best to Kenny to show him and talk to him about ideas I have gleaned. Many times, he or I already know something about a topic, but if neither of us know, then I spend the time searching thru and send it on to him.
I came across many “self-heating” ideas. Using a hot compost pile, rocket stove and even fire under the tub, but most of these still used an electrical circulating pump. I wanted something that was self-containing and if there was no power for whatever reason... something completely off grid! Then I came along the idea of thermal siphoning.
This is the action by which warm water rises and cold water falls and is based on the principle that water travels the least resistant path. In other words, if you make a loop thru a heat source the water goes in cold but comes out hot! No pumps needed to circulate, just the beauty of physics and free energy!
This has taken a few prototypes to get it working properly and it is still a project in progress, but with each change it gets better. Kenny first started with building a rocket stove and a wrapped copper tubing around the chimney which the water circulated through. This worked, but it didn't get hot enough and the fire had to constantly be fed because of the small wood box. He then fabricated a metal stove with a coil of copper tubing inside the fire box. This heated much better, but it still didn't circulate well on its own. I came along some information stating that in order for the siphoning to happen the water “tank” had to be 2 ft away and 1 ft higher than the heat source. He adjusted the height and distance of the stove and that worked! He is still working on this though because the problem at this point is that the bathtub can be drained, but the coil cannot be drained after I use the bathtub. This is because the fire is still too hot when I get out and takes a while to cool down, resulting in it being frozen by the morning. This is not good because then you are risking the coil will break as it freezes and expands. He would like to make it so that it is able to be completely drained after use and also so the stove itself is more insulated to keep the heat in better. That would help it to not lose heat quite so fast on those very cold nights.
So, the project keeps morphing as ideas and information is gained and for now, I have a bathtub again! There is something so magical and relaxing about being out under the stars and moon, basking in the quiet, soothing sounds of the night.