Fan impellers with diam­e­ters of one or two meters are often driven by AC motors. However, by the time the next stage of the Ecode­sign Regu­la­tion for fans comes into force, many of these solu­tions will no longer meet the increased require­ments. The suit­able alter­na­tive will then be new high-perfor­mance EC external rotor motors that operate at high effi­ciency levels. »