TYPES OF SOLAR GEYSERS
There are two basic types of solar geyser systems which can culminate into various configurations:
A direct solar system circulates the water that is to be heated directly between the solar geyser cylinder and the solar collector. A direct system is susceptible to frost and or freezing and should only be installed in areas that are not exposed to frost or freezing conditions.
An indirect system does not circulate the water in the storage cylinder but rather circulates a nontoxic freeze resistant fluid (glycol) between the solar geyser cylinder and solar collector. The heating of the water is achieved by indirect transfer of heat from the glycol to the water via a heat exchange mechanism and as result of this indirect systems are entirely frost and freeze resistant. Most areas in South Africa are frost prone and thus the indirect system is the best suited.