The present invention discloses a dehumidifier and a float assembly thereof, wherein the float assembly comprises a float, a press plate, a suction pipe, and a rotation shaft. The float, the suction pipe, and the press plate are fixedly connected to the rotation shaft respectively, and the suction pipe and the float are arranged at the same side of the rotation shaft, so that the suction pipe is driven by the float to synchronously rise up or fall down along with variation of water level of a water tank; the press plate is driven by the float to control a draining pump to drain when the water tank is at the high water level, thereby realizing automatic drainage. The present invention doesn't need to dispose both a fixed water tank and a movable water tank.

A valveless siphon decanter for processing fluid within a tank having a siphon tube external to the tank, the siphon tube having an output, a boom extending substantially transversely from the siphon tube, the boom providing a path for the communication of fluid from within the tank into the siphon tube, a vacuum head in association with the boom, the vacuum head having at least one orifice disposable within the tank for receiving the fluid, a vacuum source for creating a vacuum within the siphon tube and the boom to draw the fluid in through the at least one orifice of the vacuum head into the boom and into the siphon tube thereafter, a vacuum break for breaking the vacuum within the boom and the siphon tube; and wherein the siphon tube and the boom are disposed outside of the tank.