Hvac system with waterside and airside disturbance rejection

An HVAC system configured to modify an environmental condition of a building zone, the HVAC system comprising:

• a damper configured to regulate a supply of air flowing past a heat exchanger coil;
• a damper actuator coupled to the damper for driving the damper between multiple positions;
• an airside processing circuit coupled to the damper actuator and configured to:
• drive the damper actuator to a first damper position setpoint, the first damper position setpoint based on an air flow rate setpoint and a first pressure measurement from a pressure sensor;
• receive an air flow error signal, the air flow error signal based on the air flow rate setpoint and a second pressure measurement from the pressure sensor;
• determine a second damper position setpoint based on the air flow error signal;
• and
• drive the damper actuator to the second damper position setpoint;
• a valve configured to regulate a flow of fluid through the heat exchanger coil;
• a valve actuator coupled to the valve for driving the valve between multiple positions;
• and
• a waterside processing circuit coupled to the valve actuator and configured to:
• drive the valve actuator to a first valve position setpoint, the first valve position setpoint based on a fluid flow rate setpoint and a first flow rate measurement from a flow rate sensor;
• receive a fluid flow error signal, the fluid flow error signal based on the fluid flow rate setpoint and a second flow rate measurement from the flow rate sensor;
• determine a second valve position setpoint based on the fluid flow error signal;
• and
• drive the valve actuator to the second valve position setpoint.