Thermosiphonic systems: It is all down to gravity

摘要

Most solar water heaters are thermosiphonic solar thermal systems. When the sun shines on the absorber, the heat is transferred through a gravity-based circuit from the collector to the storage tank: hot water rises upwards and cold water sinks below. Thermosiphonic systems require neither backup energy nor pumps and solar controllers. They are therefore less expensive than pumped systems.rnOpen thermosiphonic systems have only one circuit, which is filled with domestic hot water. With models with flat plate collectors, the water circulates through copper pipes that connect the storage tank to the collector. With models with evacuated tubes, the tubes are connected directly to the storage tank. The circulation occurs within the individual glass tubes.