An improved thermosiphon solar heater is disclosed. The thermosiphon solar
heater includes a substantially planar collector including a plurality of
heat exchanger channels that are positioned next to one another in a
parallel relationship. The thermosiphoning solar heater also includes a
pair of headers fluidly coupled to the collector. A first header is
disposed at a top end of the collector. A second header is disposed at a
bottom end of the collector. The thermosiphoning solar heater further
includes one or more exposed storage tanks fluidly coupled to the header
and positioned in a side by side relationship next to the collector.