Fan Curves
The actual shape of blower performance curves is determined by the combined effect of the hydraulic losses of the impeller and casing. Mechanical losses including disk friction remains the same for all capacities and leakage loss is small and varies slightly with the impeller 16 head near the shaft……
As you have known, you must know what the capacity of a fan is before you consider opening a damper or increasing the fan speed. Doing so may not be safe—it could result in an overloaded motor, for example, or an unusually high power consumption—so you should be able to predict the results of any changes you may decide to make.……
This document contains introductory material designed to familiarize the user with the conventions and terminology related to fan curves. Various axial and centrifugal fan performance curves will be illustrated throughout this article with no attempt made to rationalize any particular selection.……
The term “system resistance” is used when referring to the static pressure. The system resistance is the sum of static pressure losses in the system. The system resistance is a function of the configuration of ducts, pickups, elbows and the pressure drops across Fans and Blowers equipment-for example bagfilter or cyclone……