Right now at Camp Monstro, we don’t really have a good bath solution. We haven’t hooked up gas to the Fifth Wheel just yet, and since we’re still living in Peoria, it’s probably not going to happen too soon.
In the meantime, my obsession with all things Passive Solar (and largely Passive House) have lead me to watching a lot of Youtube to find a good solution for a passive solar water heater. Fella claimed that he was able to get 150F water out of his single water heater… and he’s not even in Arizona.
I looked at pvc pipe (brittle over time), copper pipe (expensive), hose (gross), and eventually found my way to Pex-A. Pex is a high quality, potable water system… hoses really, that houses are being plumbed with these days. In fact, our whole house was just replumbed with Pex here a couple of years ago.
It’s supposed to last 50 years, and is good up to 200 degrees F.
I got to work… but after my solar heater woes… I decided to start WITH the glass, rather than trying to find glass after the box was built.
I decided on 3/4 inch Pex, not realizing that my youtube guide was using 1/2 inch Pex. More on this later.
I bought a solar fountain pump from Amazon, along with a solar panel.
I bought 3 thick glass tabletops from Facebook Marketplace. Two are 2x2 ft, the other is 2x3 ft. They are really thick, which is good.
I designed the box for the 2x2… but forgot that the pipes have to overlay themselves at one point, and had to redo it all.
I lasered the box out of 1/4 pre-lacqeured baltic birch plywood. Next time, i’d probably consider 1/2 inch baltic birch.
I redesigned the box, and checkded to make sure that the glass fit well. (It did.)
I lined the bottom of the box with bubble foil insulation, and glued it down with construction adhesive.
I glued two 1ft x 2ft tiles into the bottom on top of the foil, to help hold in heat. If a cloud passes, I want the water to stay warm for as long as possible.
We coiled the Pex in, fighting it for ever loop. 3/4 Pex is very, very stiff… but eventually we got it to work. We had to ziptie it as we went to hold it down. A real pain, I can see why they stuck with the 1/2 inch Pex.
We spray painted everything flat black.
We put metal drip edge along the sides and top, gluing it down with ample amounts of window silicone. Like, 1 tube each.
All of our fittings are in Portal, so once we’re there, we’ll add brass quick release connections to each box, and the pump. (The bathtub trough already has them.) Then we can move the pump anywhere in the setup… middle, front, or back.
