Fan Power

What is this formula?

Fan Power calculates the mechanical power required by a mine ventilation fan to deliver a specified airflow against a given pressure rise.

It is one of the most important calculations in mine ventilation because fan power directly affects electrical energy consumption and operating costs.

The formula accounts for fan efficiency, meaning that the actual input power must be greater than the useful air power delivered to the airflow.

When to use it

Use this formula when:

- Selecting mine ventilation fans.

- Estimating energy consumption.

- Designing ventilation systems.

- Comparing fan alternatives.

- Evaluating ventilation operating costs.

Example

A mine fan must deliver 45 m³/s of airflow against a pressure rise of 1800 Pa. The fan efficiency is 75%.

Data:

Q = 45 m³/s

ΔP = 1800 Pa

η = 0.75

Formula:

Pf = (ΔP × Q) / η

Substitution:

Pf = (1800 × 45) / 0.75

Pf = 81000 / 0.75

Result:

Pf = 108000 W

Pf = 108 kW

The fan requires approximately 108 kW of input power.

Applications

- Mine ventilation design

- Main fan selection

- Booster fan selection

- Energy efficiency studies

- Ventilation optimization

- Mine operating cost estimation

Note

This equation represents the ideal relationship between airflow, pressure, and efficiency. Actual installations may require additional power due to motor losses, transmission losses, altitude effects, air density variations, and system inefficiencies. Fan efficiency can vary significantly depending on operating conditions and fan type.