This Architectural Drawing is of FCU INSTALLATION DETAILS OF CHILLER SYSTEM. A chilled water fan coil unit (FCU) works by transferring heat from the air passing over the internal heat exchanger to the chilled water passing within. Cold water is supplied by a chiller unit, or reversible heat pump, which is installed in a central plant room or on the roof of a building. A fan coil unit (FCU) is a device that uses a coil and a fan to heat or cool a room without connecting to ductwork. Indoor air moves over the coil, which heats or cools the air before pushing it back out into the room. For more details and information download the drawing file.