Low-pressure centrifugal fans — silent ducted ventilation for residential and commercial use

Low-pressure centrifugal fans are the foundational category of ducted mechanical ventilation — the equipment that provides extraction or supply in simple duct networks with short to medium duct runs and moderate hydraulic resistances, up to 200–300 Pa. The centrifugal rotor with forward-curved or radial blades generates an airflow perpendicular to the rotation axis, delivering static pressure superior to axial fans but with significantly lower noise levels than medium and high-pressure models.

They are the right solution for residential mechanical ventilation — bathrooms, kitchens, bedrooms and hallways in apartments and houses — where duct runs are 2–8 metres long with a few bends and distribution grilles. They are also widely used in small and medium offices, retail shops, lightly ventilated restaurants, medical consulting rooms, classrooms and any commercial space with moderate ventilation requirements. Silent operation at low and medium airflows — below 40 dB(A) for compact models — makes them preferable to axial fans in permanently occupied spaces.

The ventilation.ro range includes Casals and Nicotra Gebhardt models with airflows from 200 m³/h to 4,000 m³/h, with circular or rectangular connections, single-phase (230V), with standard speed controller compatibility. Galvanised steel or ABS plastic casing allows wall, false ceiling or duct mounting.

How to choose: calculate the total static pressure of the installation (ducts + bends + grilles + filters). If the sum exceeds 300 Pa, move to the medium-pressure category. If the sum is below 100 Pa and the installation has no ductwork, an axial fan may be sufficient and less expensive. The optimal range for low-pressure centrifugal: 100–300 Pa, with airflows of 200–4,000 m³/h.

👉 Medium-pressure centrifugal fans — for longer and more complex installations 👉 Inline fans — compact duct alternative