Power, Reliability & Efficiency. The reason why Delta PAG fans are superior revolves around our Brushless Motor Technology.  Brushless motors are "power-dense" small, yet very powerful. This allows for a thinner fan with longer fan blades thus more airflow.  Brushless motors have a longer lifespan because there are no brushes to wear down. The operating life of brushless motors is rated at 50,000 hours vs. 3,000 hours for typical brushed motors. Brushless motors increase motor reliability, reduce noise & reduce heat.  Brushless motors are far more efficient than brushed  motors due to multiple phases (3 phase vs 2 phase) & no brush/commutator losses. As a result, brushless motors consume a fraction of the amps while doing the same/more work. Delta PAG's Brushless fans are flat out better because brushless motors are better.