DHW -- Domestic Hot Water, Basically any water in your home that is safe to drink that has been heated for cleaning or bathing.
SOLAR HOT WATER -- Using the energy from the sun to heat water.
SDHW -- Solar Domestic Hot Water
CLOSED LOOP SYSTEM -- In colder climates, because a portion of the SDHW sytem is exposed to below freezing temperatures, the collector must be filled with an antifreeze solution. The heat from the collector portion of the system must pass on this heat through a heat exchanger but the antifreeze never mixes with the DHW.
