Heating and cooling energy consumption measurements are critical for operations, controls, and fault detection and diagnosis of heating, ventilation and air conditioning (HVAC) systems. Generally water flow has to be measured in order to determine energy consumption in either chilled water systems or hot water systems. Economical and accurate water flow measurements are essential to develop energy meters. Since pump performance relates actual pump water flow to pump head and power, theoretically water flow through a pump can be determined by other pump performance characteristics, such as pump head and motor power. This paper presents the theoretical model of pump flow stations based on pump head and motor power, and the experiments and results of a cooling energy meter using a pump flow station developed on the chilled water system at a facility.