Plumbing systems have already existed during ancient times. In fact, at around 1700 BC, The Minoan Palace of Knossos in Crete first featured a terra cotta-based piping that provided water for faucets, as well as faucets made of marble, gold and silver. During the Roman period, personal bathrooms and lead pipes have already existed (1000 BC - 476 AD). Rome's public baths were already equipped with silver faucets along with fixtures made of gold and marble.
Since then, public systems have changed, including faucets. For many decades, faucets had two handles - one for hot water, and the other for cold water. In 1937, however, this design changed, and this change was initiated by a college student named Al Moen. One fine day in 1937, he turned the faucet handle to wash his hands but scalded them since the water came too hot. This gave him the idea of designing a single-handle faucet.
Between 1940 and 1945, he designed various kinds of faucets: from a double-valve faucet to a cylindrical design, and finally he sold his first single handle mixing faucet in the latter part of 1947. By 1959, his design was used in a million homes in the United States and sold in around 55 countries all over the world. Today, single-handle faucets are popular and can be found in about 50% of American homes.
Aside from single-handed faucets, Al Moen also came up with other inventions in his lifetime, which included the replaceable cartridge (to eliminate washers in the faucets), push-button shower valve diverter, screen aerator, flow control aerator, pressure balancing shower valves and swivel spray.
Aside from Al Moen, Landis Perry was also involved in doing innovative faucet designs. In 1945, he designed his first faucet ball valve which aimed at providing a combined blending control and volume with an effective means for sealing valve elements. This design was patented in 1952 and was first introduced in 1954 by Delta faucets (who bought the patent beforehand). Four years henceforth, their sales topped a whooping $1 million.
About two decades later, Wolvering Brass patented the ceramic disk for water control. Unlike rubber-based cartridges, ceramic discs are lapped and polished in such a way that their flatness is only measured in light bands. Ceramic disks tend to last a lot longer than cartridges since they have high wear resistance and are able to provide a more accurate control. These disks are widely used today.
More recent innovations in faucets include built-in cartridges used to reducing the level of lead, cysts and chlorine, built-in pull out sprays, electronic faucets as well as those designed for disabled people. Electronic faucets were introduced in the early 1980's for hygienic and water conservation purposes, and come with infrared beams that detect motion. When a person happens to put his hand underneath the faucet, the infrared beam is disrupted, and this disruption triggers the water to run. In addition, battery-operated electronic faucets have also been distributed. More developments will surely come in and improve the lives of many homeowners.