Carrier is offering an electronically commutated motor (ECM) direct-drive fan option for the Aero® 39M commercial air handler product line. According to company officials, adding the new ECM fan option enables customers to further improve the system’s energy efficiency. Onboard electronics determine the position of the rotor, which then provides an electronic pulse to actuate the motor windings. These electronics control the speed and level of input power to allow the motor to efficiently deliver the correct level of airflow based on building demand. Since the variable-speed control is built into the motor, it negates the need for an external speed controller.