As opposed to AC motors, DC electric motors are powered from direct current (DC) power and are mechanically commutated machines.
DC fans are widely regarded as the most efficient type of fan. They consume significantly less power than AC fans. In fact, DC fans consume up to 70 percent less energy to produce the same output as other fan types.
DC fans make use of a new type of electrically commutated motor (ECM). Not only are these motors ultra-efficient, they are also incredibly quiet.
DC fans generally use less voltage than AC fans. Lower voltage also makes DC fans potentially less dangerous.