Axial fans with external motor — the solution for high temperatures and heavy-duty applications

Axial fans with an external motor represent a specialised construction in which the electric motor is positioned entirely outside the airstream being moved. The axial rotor is mounted on an extended shaft or a support structure that keeps the motor on the outside, shielded from the hot, corrosive or pollutant-laden air passing through the fan.

This architecture solves a fundamental problem in industrial ventilation: how to ventilate a space with air at high temperatures (80–200°C) or with aggressive chemicals without destroying the electric motor. A standard motor mounted in the airstream at 120°C will fail within a few hundred hours; the same motor positioned externally, cooled by ambient air, operates for years without intervention.

Used in the iron and steel and metallurgical industry (hot air extraction near furnaces and rolling mills), ceramics and glass industry (kilns and firing ovens), chemical industry (processes with corrosive vapours at high temperatures), thermal power plants (flue gas extraction downstream of heat recovery units) and wherever the industrial process generates air at temperatures incompatible with standard motors.

The external motor also facilitates simplified maintenance: the motor can be inspected, lubricated or replaced without dismantling the rotor and without entering the hot air zone. This significantly reduces the lifetime maintenance cost of the equipment.

How to choose: specify the maximum temperature of the air being moved and the maximum ambient air temperature at the installation location (which cools the external motor). Verify that the bearings and shaft seals are rated for the temperature conditions and type of airflow. Consult our technical team for applications with temperatures above 100°C or with corrosive substances.

👉 Compare with belt-driven axial fans — another high-temperature solution