Water supply systems have long been used in homes and buildings. A water supply system uses piping to supply fixtures such as tubs, sinks, and shower, with clean, potable hot and cold water. To do so water supply systems use pipes, water heaters, valves, outlets, storage tanks, possibly one or more pumps and other devices such as splitters to distribute water from a water inlet to the various fixtures. A well designed water supply system can reliably supply clean water to users at designed rates and temperatures.
While modern water supply systems have proven themselves to be highly valuable, and while they are very often required in homes and other buildings, water supply systems are not without problems. For example, some parts of the United States and many parts of the world face water shortages so water cannot be wasted. In addition, energy, water heating costs can be of major concerns in some locations and applications. These are problems because to obtain hot water from a fixture can require running cold or tepid water from the hot water fixture until the water line is cleared of cooler water and the hot water line fills with hot water.
The cold or tepid water usually just goes down a drain. While a minor problem if the hot water fixture is near the water heater, if the fixture is a distance away significant amounts of water can be wasted. Not only is the running water lost its residual heat is also lost. So a hot water fixture fifty feet (50 ft.) away from a hot water heater may cause the loss of a significant amount of water and residual heat until hot water arrives at a suitable temperature.
The foregoing problems may be intolerable, particularly as water shortages continue to worsen. Therefore, a need exists for advanced water supply systems that drain water from a hot water fixture into a water recovery storage tank before water comes from the hot water fixture, that then re-fills the hot water line with hot water to supply the hot water fixture with water at the proper temperature, and then returns the drained water to a hot water heater.