52b8100c_na___Solar_Hot_Water__A_Primer__3
[0] Solar Batch Water Heater [1] Open loop; Integrated collector & storage; Freeze protection generally limited to infrequent or light freeze climates [2] Simple; No moving parts [3] 
Freeze protection typically poor; Inefficient in cold climates; Small systems only
Arizona Solar Center - Your Guide to Solar and Other Renewable Energy Sources in Arizona - Solar Hot Water: A Primer
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