Fan Power Calculator
What is Fan Power?
Fan power, often measured as Brake Horsepower (BHP), is the actual mechanical power required at the fan shaft to move a specific volume of air against your system’s resistance. This measurement determines the size and capacity of the electrical motor needed to run the dust collection system effectively. It can also help us prevent motor overloading, calculate long-term operating costs, and optimize the overall energy efficiency of the equipment.
How to Use This Calculator
⦿ Enter the System Airflow (CFM): Input the total volume of air your system needs to move.
⦿ Enter the Static Pressure (in. w.g.): Input the total system resistance or static pressure drop in inches of water gauge.
⦿ Enter the Fan Efficiency (%): Input the rated efficiency of the fan (often between 60% and 85% for industrial dust collection fans).
⦿ Calculate: Click the calculate button to determine the Fan Power, also known as Brake Horsepower (BHP), required to drive the fan.
Understanding the Formula
Fan Power (BHP) = (CFM × Static Pressure) ÷ (6356 × Fan Efficiency)
Calculating fan power is essential when sizing a new industrial exhaust fan or upgrading a motor for your baghouse. This formula calculates Brake Horsepower (BHP), which represents the actual power required at the fan shaft.
The constant 6356 is a standard engineering conversion factor used when measuring airflow in CFM and pressure in inches of water gauge. Because no fan is 100% efficient at converting mechanical energy into aerodynamic energy, the formula divides the ideal power by the fan’s mechanical efficiency to give you the true real-world horsepower requirement.
Importance of Fan Power in Baghouse Design
Correctly sizing your fan power ensures the system maintains the proper airflow to capture dust and overcomes static pressure resistance. It also prevents motor overloading and optimizes energy consumption. Undersized fans suffer from poor suction, dust settling in ductwork, and reduced collection efficiency, while oversized fans waste electricity and increase mechanical wear.
Nota: This calculation is a helpful reference point, but factors like air density, temperature, elevation, and complex duct layouts also affect performance. Always consult an expert like Baghouse.com for accurate sizing.