FAQ: What is the difference between series and parallel fan setups?

In PC environments, the options for fan placement are usually predetermined by the application. By contrast, when designing custom setups that require more ventilation than a single fan can deliver, it is important to consider whether these fans should be placed in series or parallel operation. In general, combining axial fans in series does not increase the airflow but increases the air pressure. On the other hand, running fans in parallel does not increase the static pressure but increases the airflow. The following article sums up the theoretical backgrounds and provides some general guidelines for designing series and parallel operation setups.