The intelligent-fluid-SYSTEM is a one-pipe system in which the previously used cold and hot water pipe system is superfluous. The elementary component of the if-SYSTEM is the if-Multibox developed and patented by LoccoZ. The if-SYSTEM is based on the idea of making all water mixing operations centrally in the Multibox and to serv the water points exclusively with the exact amount of water and temperature they had previously transmitted to the Multibox via a bus system. Each valve is individually controllable. Due to the reduced cable lengths, less water is circulating and less heat energy is lost in the piping system. Also no boiler is needed, which saves electricity. The regulated valves do not cause any temperature or pressure fluctuations. The specially programmed valve movement of the if-SYSTEM valves effectively prevents pressure surges and the associated water damage. Since a low requirement for installation materials is needed, CO2 can also be saved. The if-SYSTEM fulfills all hygiene requirements, as no bacteria formation is possible due to a digitally controlled rinsing program and a controlled Legionella rinsing is available.