Helios Fans HRFD 355÷8÷4

The Helios HRFD 355÷8÷4 is a powerful and reliable cased axial fan designed for industrial and commercial ducted ventilation systems requiring dual-speed functionality. This model features a robust direct drive mechanism with a Dahlander wound motor for efficient 2‑speed operation.

Its cylindrical housing is fabricated from galvanised sheet steel, offering high durability and resistance to corrosion. The unit includes flanges on both ends, making it compatible with standard ducting systems. All dimensions and flange mounting holes conform to DIN 24155 specifications. An external terminal box is integrated for convenient electrical access.

At the heart of the fan is a dynamically balanced impeller with aerodynamically profiled blades, manufactured from impact-resistant polymers to ensure long-lasting performance and stable airflow. The impeller is engineered to operate effectively in ambient temperatures ranging from ‑30 °C to +60 °C.

The HRFD 355÷8÷4 is powered by a totally enclosed 3‑phase squirrel cage motor featuring Dahlander windings, enabling pole-switching for two distinct speed settings. It is maintenance-free and fitted with sealed-for-life ball bearings, delivering quiet and reliable performance throughout its service life. This model is ideal for applications demanding adaptable airflow with durable, low-noise operation.