| Solar hot water heating systems are a basically | | | | collectors, the pump and the tank with heat |
| straightforward design. Solar collectors reheat | | | | exchanger are the fundamental components. |
| water all through the day, which is stored in an | | | | Drainback systems are so named because the |
| insulated reservoir to keep it warm for ongoing | | | | solar collectors drain when they are not being |
| use. But sub-zero temperatures can bring this kind | | | | used. For this reason, you can use either water or |
| of system to a standstill. But fresh and improved | | | | antifreeze in the system. But for highest |
| methods have been developed that allow solar | | | | assurance that the system will not freeze, people |
| hot water systems to operate effectively even in | | | | frequently choose to use antifreeze as an extra |
| cold climates. Here is a basic explanation of how | | | | precaution, principally in regions that frequently |
| they work. | | | | experience temperatures below zero. |
| After a few decades of testing with solar hot | | | | A thermosiphon system also uses a isolated solar |
| water systems, most knowledgeable users have | | | | collector, along with the pull of gravity. And it |
| determined that the closed loop design is the | | | | allows for the use of an insulated storage |
| most successful for climates with freezing | | | | reservoir for more dependable hot water delivery. |
| temperatures. Because oxygen is eliminated from | | | | When using any of these systems in cold areas |
| the system, pumps will not corrode and will have | | | | where freezing is an issue, both the piping and the |
| a longer lifespan, saving you time and money for | | | | storage tank should be placed indoors and |
| maintenance and replacement parts. | | | | properly insulated to provide hot water even on |
| The system is filled with an antifreeze blend | | | | the coldest days. |
| (propylene glycol) at the time it is installed. It then | | | | Even though the collectors drain when not in use, |
| circulates between the solar collectors (where it is | | | | they drainback system is still a closed loop |
| heated by the sun during the day) and the | | | | system. It requires a robust pump in order to |
| storage tanks, which provide heat during the day | | | | return the drained liquid to the solar collector once |
| and night. There are several smaller workings that | | | | it has been drained. But it is a good choice for a |
| allow the antifreeze to expand and contract, and | | | | homeowner who desires a solar heating system |
| which prevent too much pressure from building up | | | | that is uncomplicated to maintain. |
| in the system, among other things. But the solar | | | | |