Fan & Blower Noise Enclosure

Industrial fans and blowers are among the most persistent sources of workplace and community noise. Without acoustic treatment, a 400 kW centrifugal blower can generate 95–105 dB(A) at 1 m — requiring PPE for all nearby workers and potentially violating local environmental noise limits.

HEMU Acoustics Fan & Blower Noise Enclosures are engineered around the specific aerodynamic requirements of the fan system. Unlike generic acoustic boxes, our enclosures are designed to maintain the fan's performance curve while achieving maximum noise reduction. Airflow enters and exits through acoustically lined splitter silencer ducts that provide 15–20 dB(A) insertion loss at the air openings — the dominant noise path for fan enclosures.

The enclosure shell typically achieves 30–35 dB(A) insertion loss on the direct transmission path (ISO 11546-1). Combined with the silencer ducts, overall radiated noise reduction of 15–25 dB(A) is achievable, depending on fan type, speed, and frequency content.

Enclosure panels are fabricated in hot-dip galvanised steel (1.5–3 mm) with a 50 mm mineral wool acoustic lining. Access doors provide entry for maintenance without requiring enclosure disassembly. All duct, conduit, and cable penetrations are sealed with acoustic putty pads to prevent acoustic short-circuit.

Vibration isolation is integral to the design: anti-vibration mounts under the fan baseplate and flexible acoustic expansion joints on duct connections prevent structure-borne noise transmission to the building frame.