Domestic water supply
A local authority has the duty to ensure that every dwelling in its area is provided with a sufficient supply of water. Sources of water include rain-water, surface water, lakes and rivers, and underground water. Some purification is often necessary to remove impurities and reduce the hardness. Public water supplies are sterilized before being passed to the consumer by treatment with chlorine or chlorine and ammonia.
Water is drawn from the wells with submersible electric pumps. Underground exterior water-supply pipes are cast-iron with threaded connections to contain the pressures applied to the fluid.
Within the building, copper tubing with soldered connections is used for distribution; plastic pipes are also used. The domestic water supply is divided into cold and hot system.
Hot water and heating installations
In a domestic hot water system the heat source - natural gas or fuel oil - is applied to a boiler in which water is heated and circulated by an electrical pump in insulated copper pipes. The pipes can be connected to cast-iron or finned tube steel radiators. They are placed near the areas of greatest loss. Temperature control in hot-water system uses a thermostat to adjust the pumped flow rate of water to vary the heat.
Domestic hot water supply may be provided by various system: direct and indirect system and other alternative system.