Batch: This is as uncomplicated as the heater gets. It's just one or several water tanks inside the solar collector (no tubes in it.) Water is heated directly in the tank, and as gravity or natural convection (the tendency to hot water to rise) to move the water from the tank into the pipes at home.
Thermosiphon: water tank separate from the solar collector. Cold water passes through the solar collector tubes, pumps and natural convection resulting hot water storage tank. From the reservoir, the water travels into the water pipes at home.
Active systems generally fall into one of three categories:
Direct: the water moves through the solar collectors and the tank with electric pump and controls.
Indirect: instead of hot water, solar collector heat, "heat" of liquid, such as antifriz.Antifriz then flows into a sealed heat exchanger, where it is surrounded by vodoy.Voda takes the heat from the coolant (but never mixed with it), and then is pumped into the tank.
Drainback: gutter system, as a system of indirect, except that it uses distilled water as a coolant fluid, and has a separate "water waste" tank of distilled water. All heat pump fluid out of the system and in the interior of the tank makes it ideal for cold weather, as the fluid is not exposed to extremely cold weather.
