Outdoor power supply air duct design

•There are different duct design methods: qEqual friction: Size based on chosen friction loss rate (per 100 ft) for each duct section to balance the pressure gradient (commonly used) qEqual velocity: Size based on maintaining a constant velocity for duct sections (applicable for simple or industrial systems to carry particles out) qBalanced capacity: Equal pressure drops from fan to outlets of each branch (e.g., VAV systems) qStatic regain: Duct size at the fan is selected using the friction chart to get the starting velocity. [pdf]