Active and passive solar pre-heat systems.(Eatherton On Hydronics)
SOLAR HOT WATER pre-heat systems fall into two basic categories–active and passive types–with numerous subcategories.
A passive solar DHW pre-heater is also known as a breadbox heater or batch heater. It is essentially a large (30- to 40-gal.), glass-lined storage tank that is built into a super-insulated, triple-glazed box […]