Saturday, July 21, 2012

First Solar Panel Started.

I spent the whole afternoon today building the solar collector to heat our hot tub. This is an experiment to familiarize myself with the technology. About half of the panel is built, and hopefully, I will have it running by the end of the weekend. First was putting the heat spreader plates on top of the plywood sheet and mark each pex run.
Each line is where the pex tubing will lay. This will help, particularly with the problem I will encounter in the next step.
At the end of the first pex run, I had to bend the pex tubing to lay on the next line. Just to be sure I would not kink the tube, I checked on line the minimum bending radius: 5". My mistake was to think diameter instead of radius. I have 5.5" between lines, so that is 2.75" radius, too short. The solution was to go every 2 or 3 lines, and come back on the next run. Here the first two lines are laid.
Next, the four fist lines laid.
Seven lines laid so far, three more to go.
One more to go. All this done with a bending radius no less than 5".
Now the painting, after cleaning the plates with alcohol. One spray can of black rustoleum is not going very far.
I went tonight and bought a liquid can of high temp black paint. Writing the blog, I realized that there will be a problem with this design. With the way I laid the lines, it won't drain properly. That is OK for a hot tub that can be drained for the winter. For the hot water heater however, I will have to get pex that can be bent with a 2.75" radius, or find another way, such as running two lines in parallel. And that is why I started my solar projects with an experiment :-)