A fan curve is one of the most useful tools in ventilation engineering because it tells you, at a glance, how a fan will behave when installed in a real system. Instead of giving only a single rating, the curve shows how airflow, pressure, power and efficiency change together over the whole operating range. For mining and industrial ventilation, this information is critical for safe design, energy efficiency and troubleshooting.
First, a fan curve tells you the relationship between airflow (Q) and pressure (ΔP). On the chart, airflow is plotted on the horizontal axis and pressure on the vertical axis. The main curve shows that as you ask the fan to deliver more airflow, the pressure it can develop decreases. This helps you predict whether the fan can overcome the resistance of ducts, filters, scrubbers, mine roadways and other components at the air quantity your process or mine requires.
Second, the fan curve tells you about power consumption and efficiency. Alongside the pressure–flow curve, there are usually additional curves for power input (kW or hp) and efficiency (%). These curves show how much electrical or mechanical power the fan will draw at each airflow, and how effectively that power is converted into useful air movement. By reading these curves, you can estimate operating cost and check that the fan will not overload its motor at the chosen duty point.
Third, a fan curve tells you which part of the operating range is most efficient and stable. The efficiency curve typically has a broad peak. Duty points in this region deliver the required airflow and pressure using less energy, with lower noise and usually more stable operation. Points far below or above the efficient region may be noisy, waste power or even risk instability, especially for high-pressure fans.
Most importantly, a fan curve allows you to find the actual operating point when you also know the system curve. When you plot your system resistance (pressure vs. flow) on the same axes, the intersection between the system curve and the fan curve is where the fan will operate. This tells you the real airflow and pressure you will get, not just the catalogue value. For mine ventilation and heavy industry, where safety and compliance depend on verified air quantities, this intersection is a key design check.
In summary, a fan curve tells you: how pressure changes with airflow, how much power the fan will use, how efficient it is across the range, and where it will actually operate in your mining or industrial ventilation system.
