ebm-papst Air Technology Expertise

Electronically commutated (EC) motors offer several benefits over traditional alternating current (AC) motors. EC motors are designed to provide significantly greater energy-saving potential. When combined with a fan, an EC motor operates with higher efficiency to conserve energy and promote environmental sustainability. This efficiency becomes even more apparent when multiple fans are used because, unlike AC fans, which operate in an on/off manner, EC fans offer continuous speed variability. To reduce airflow, AC fans must be partially turned off, while EC fans can be easily adjusted to reduce speeds, resulting in energy savings.

System Curve
Air handling units, which include components like heat exchangers, filters, constrictions, and bends, introduce resistance to airflow, causing a pressure drop. This drop is represented by a system curve, which changes with various airflow levels. The mechanical work of the fan creates a pressure increase, which counteracts the pressure drop and ensures the desired airflow (qv) is maintained throughout the system.

Fan Curve
A fan delivers continuous airflow and a static pressure increase to counterbalance system pressure losses. This static pressure increase (pfs) varies with the conveyed airflow (qv). When plotted on a coordinate system, the variables shape a characteristic curve representing fan performance at all potential operating points. The fan type determines the shape of the fan curve and the optimal operating range. Noise levels and efficiency peaks are minimized within the fan's optimal operating range, which is highlighted in the diagram above as an example.

The operating point is defined by the coordinates of the necessary airflow and the resulting pressure drop within a system. When choosing a fan, it's vital to ensure it can deliver the needed airflow at the correct pressure increase. In diagrams like the one above, the operating point can be found at the intersection of the system curve and the fan curve. This represents the conditions under which the fan will function within the system.

EC Technology

       •   Values based on 50Hz, according to IEC 60034-30
       •   Achieves up to 90% efficiency, exceeding typical levels of 70% to 80% of AC motors
       •   Surpasses IE4 energy efficiency class standards for conventional motors
       •   Offers infinite speed variability with integrated commutation electronics
       •   Speed control significantly reduces noise and energy consumption