>Course on constructing solar hot water panels
From the 6th to 9th of December 2012 we hosted a course on solar hot water panels. The main objective to the course was to build a solar hot-water panel of two square meters starting with some recycled materials and minimize what is newly acquired. The course, with four participants, was planned and lead by the department of Sunseed’s Appropriate Technologies.
A theoretical introduction included exploration of what impact the use of the sun to heat water might have on reducing fossil fuel consumption and, therefore, on climate change. Then we visited various water heating installations in the town of Moulins, where all houses have their own power generation systems and hot water systems based on various techniques.
The practical workshop began with the removal of one of the two solar panels from the main house of Sunseed, which was to be renewed and reinstalled during the course.
The materials to reuse were:
- Copper sheets from old panels.
- Copper pipes and elbows of various diameters welded together.
- Tempered glass panel from the former main house.
- Galvanized iron sheet deteriorated (from the old panel).
- Glass wool.
The new acquisition was:
- Copper pipe for collector.
- Aluminium profile for the frame.
- Glass wool
The copper plates were initially flattened, cleaned of old tin and re-shaped to accommodate the newly acquired copper tubes used for this purpose. At the same time, test-welds were made with a tin-welding torch to properly assemble the heat-collector. We also prepared and cleaned elbow joints of different sizes for the assembly of the copper pipes.
When all the pieces of copper were recovered, and when we were well practiced on welding, the pipes were welded together and the heat collecting plates were adhered. Then we proceeded to paint the heat collector matte-black (to attract sun), and set the paint using a compressed air gun.
The galvanized iron sheet was cleaned of rust (where it had appeared after a previous life of 20 years!) and then we proceeded to cover it with zinc paint and an exterior paint-job to give it a little more weathering protection in the exposed parts.
The aluminum was cut to the proper size and shaped to the design being done. The rear plate of the frame-sides were joined with rivets, but we left an open side prepared so we could make the final placement of the tubes and glass. The glass wool insulation was placed by sliding it into the frame assembly. With care not to break it, the top layer of tempered glass was also placed. We closed the assembly by finally completing the riveting under the last segment and then applied silicone to give it waterproof joints.
Participants were able to take part in all the processes of panel construction, and they were happy to be in contact with all materials and tools. By using recycled materials and learning the “do-it-yourself techniques”, the participants’ capacity to use such materials has grown – they can be more confident to do it themselves, and be able to avoid using primary source materials or commercial panels, too. We hope they will try it themselves in the future!
Pako Ibáñez, Appropriate Technology Coordinator, Sunseed.