Building A DIY Solar Collector
Many environmentally conscious home owners, who chose to install solar systems to use for heating, often find the prices for solar collectors to be a stumbling block. Despite the growing popularity, availability, and price decrease of solar energy systems, the cost of solar collector system can easily run into thousands of dollars. One way to reduce this enormous expense is to build the solar collector yourself. A typical DIY flat panel solar collector can be constructed for about 70% less than its factory manufactured analog, and is considered to be relatively easy to put together.
The savings start with the choice of materials. Being that piping is one of the most expensive components of the collector, switching copper for PEX-AL-PEX pipe, will immediately slash a substantial amount from the total cost. Although PEX-AL-PEX is very popular, safe and reliable to use in plumbing and radiant heating, a certain level of caution is required when using it in solar energy harvesting applications. The drawbacks of using PEX-AL-PEX include the possibility of exposure to UV and a threat of damaging tubing due to high temperatures. In order to resolve these issues, and to avoid permanent damage, the tube needs to be either covered or be wrapped in tin foil at all times, while the temperature needs to be closely monitored and controlled by keeping it within tested limits of the tubing. Another factor to keep in mind is that when compared to copper, PEX tends to be about 10%-15% less efficient. However, the significant overall savings make the reduced efficiency factor practically irrelevant.
Other materials used in construction include aluminum strips, wooded frame, sheet of plywood, insulation and glazing. Putting everything together does not require any expertise or special skills. Tubing is laid on the plywood in a similar pattern as PEX tubing in radiant heating systems, and is covered by aluminum strips, which serve as heat absorbers. The plywood sheet is then inserted into a wooden frame and glazing material is attached. When it comes to glazing, the material has to withstand high temperatures and preferably be in a low price range. Possible glazing materials that are often utilized include polycarbonate, glass and fiberglass. A sheet of insulation is attached to the back of the frame, to reduce heat loss.
Once the collector is assembled, the next step is to mount it. While it might sounds like an easy task, mounting has an enormous effect on the way the collector is heated, and installing it at a wrong angle, or facing it the wrong way can diminish its efficiency, cause damage, or even destroy it. The change in position of the sun during summer and winter needs to be considered as well.