ECM (Electronically Commutated Motor) technology uses direct current (DC) power which has the motor run more efficiently than conventional PSC (Permanently Split Capacitors) motors. When an ECM motor you will enjoy up to 82% of electricity energy efficiency. ECM motors draw less power (watts) than PSC motors, which result in energy savings of up to 50% during the heating and cooling modes and up to 75% (watts) during continuous fan operation, making them the most efficient motor choice for your furnace. ECM motors also run physically cooler which will have the motors last longer than conventional PSC motors.