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Fan Power Calculator

Unit system

The calculation represents one fan duty point.

01

Duty point

Airflow, pressure rise and efficiency at the selected operating point.

Typical efficiency is only a starting point; use manufacturer selection data whenever available.
02

Drive and motor

Parameters used to estimate electrical input and motor size.

03

Results

For 10,000 m³/h at 800 Pa.

Fan shaft power 2.85 kW 2,849 W · 3.82 hp
Air power2.22 kWbefore fan losses
Motor output required2.85 kWincluding drive losses
Electrical input3.17 kWat the stated motor efficiency
Specific fan power1,140 W/(m³/s)based on electrical input
Next standard motor size 4 kW Required with a 15% margin: 3.28 kW.
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Guide

Using the result

Total or static pressure

Total pressure is preferred for the energy balance. If a catalog gives static pressure only, account for velocity pressure consistently.

Efficiency at the duty point

Use the efficiency at the actual airflow and pressure, not simply the maximum value on the fan curve.

Motor selection

The recommendation includes drive losses and the stated margin. Check starting, control and overload requirements against motor data.

Basic relationship: P = Q × ΔP / η. Compressible flow, high pressure ratios and special applications require manufacturer performance data.