The Helios HRFD 250÷4÷2 is a high-performance axial duct fan featuring a cylindrical galvanised sheet steel housing with flanges on both ends for easy installation, conforming to DIN 24155 standards.
It incorporates a highly efficient, aerodynamically optimised profiled impeller made from durable polymers, designed for dynamic balance and reliable operation within a temperature range of ‑30 °C to +60 °C.
Powered by a totally enclosed, maintenance-free 3‑phase squirrel cage motor with Dahlander winding, this fan offers two-speed operation via pole switching for flexible airflow control. The motor is equipped with low-noise sealed-for-life ball bearings, ensuring quiet and durable performance ideal for industrial and commercial ventilation applications.