A system includes a chamber, an inlet valve, a control device, and a recycle pipe. The chamber is configured to perform a semiconductor process and including an output port. The inlet valve is coupled to the chamber and a supply pipe. The controller is coupled to the inlet valve and the chamber. The recycle pipe arranged outside the chamber and coupled to the chamber. The recycle pipe is independent from the supply pipe. The controller is configured to determine whether the chamber is idle, and is configured to control the inlet valve based on the determination of whether the chamber is idle. When the controller closes the output port of the chamber and opens the inlet valve, water from the supply pipe flows into a wall of the chamber through the inlet valve first and then flows into the recycle pipe.