The supply flow setpoint for AHU 3 was increased from 14,500 CFM to 15,000 CFM. This is due to inconsistent heat output from the AHU. The heating coil air-proving switch is factory set at ~.5 inches of water column, and the PI loop of the AHU controller oscillates the flow ~ 1000 CFM. At the lower end of air flow, this is not high enough to keep the proving switch closed and the heaters de-energize until the flow increases again, leading to ON/OFF operation and inconsistent heating. Increasing the flow rate allows the flow switch to remained closed at the lower end of oscillation.