Parallel operation

Parallel operation involves using two or more fans in parallel.

The airflow volume produced by two fans in parallel, under free-space conditions, is twice that of a single fan. However, when parallel fans are used in situations with high system impedance, the higher the system impedance, the lower the increase in airflow that can be achieved by parallel fans. Therefore, parallel applications are only recommended in situations with low system impedance, i.e., where the fans operate under almost completely free-flow conditions.

Operating curves of parallel fans and individual fans

Series operation

Series operation involves using two or more fans in series. The static pressure generated by two fans in series can double under zero airflow conditions, but it does not increase airflow in free space. Adding another fan in series increases airflow in systems with higher static pressure. Therefore, series operation is most effective for systems with high system impedance.

Operating curves of series fans and individual fans