Solar Water Heaters constitutes collectors, storage tanks and backup electrical heating(optional) and with water Circulation Pumps if required. There are primarily two types of collectors in general usage: Flat plate and Evacuated-tube depending on the quality of water.
A flat plate collector,the most common type, is an insulated, weather-proof box containing a dark absorbed plate under one or more transparent or translucent covers. Evacuated-tube collectors are made of rows of parallel, transparent glass tubes. Each tube consists of a glass outer tube and an inner tube or absorbed covered with a selective coating that absorbs solar thermal energy but inhibits radiative heat loss. The air is withdrawn (“evacuated”) from the space between the tubes to form a vacuum, which eliminates conductive and convective heat loss.
Solar water heating system capacities range from 200 liters per day to 1 lac liters per day and can be used for following applications:
Domestic: Homes, Bungalows and Apartments.
Commercial: Hotels, Hospitals and Hostels.
Industrial: Preheating boiler feed water and Process Industries.