Abstract: A chilled water circulation system includes a thermal source, an AHU, a pump, and a control section. The thermal source chills water to a specified temperature. The AHU cools air by heat exchange with the chilled water. The pump feeds the chilled water having a flow rate corresponding to an operating frequency of a power inverter to the AHU. The control section calculates a degree of surplus, which indicates surplus capacity of the AHU to cool air, on the basis of information indicating the state of the AHU. If the degree of surplus is not lower than the specified threshold, the control section controls the operating frequency of the power inverter, thereby decreasing the flow rate of the chilled water fed from the pump. If the degree of surplus is lower than the specified threshold, the control section increases the flow rate of the chilled water fed from the pump.

Abstract: A cold/chilled water circulation system comprises a thermal source, an AHU, a pump, and a control section. The thermal source cools chilled water to a specified temperature. The AHU is an air conditioner that cools air by heat exchange with the chilled water. The pump feeds the chilled water having a flow rate corresponding to an operating frequency of a power inverter to the AHU from the thermal source. The control section calculates a degree of surplus, which indicates surplus capacity of the AHU to cool air, on the basis of information indicating the state of the AHU. The control section controls the operating frequency of the power inverter, to decrease the flow rate of the fed chilled water if the degree of surplus is not lower than the specified threshold, and to increase the flow rate if the degree of surplus is lower than the specified threshold.