HVAC Acoustic Enclosure

HVAC plant is a leading cause of noise enforcement action and planning objection for commercial developments. Rooftop chillers, cooling towers, and air handling units can exceed local night-time noise limits (typically 40–45 dB(A) at residential boundaries) by 10–20 dB(A), triggering complaints, fines, and costly retrofit mitigation.

HEMU Acoustics HVAC Acoustic Enclosures are designed for both new-build plant rooms and retrofit applications. The fundamental design challenge for HVAC enclosures differs from compressor or pump enclosures: HVAC equipment requires large volumes of airflow for heat rejection. An enclosure that restricts airflow increases condensing pressure, degrades efficiency, and may trigger safety shutdowns. Our design process begins with the equipment manufacturer's minimum airflow requirement and works backward to the quietest enclosure that meets it.

The enclosure uses splitter silencer intake and exhaust louvres — weather-rated acoustic baffled louvres providing 10–15 dB(A) insertion loss at the air opening while maintaining the required free area. Roof panels use mineral wool-filled composite cassettes with perforated steel inner faces (NRC 0.85). All louvres and connections use flexible acoustic expansion joints to prevent vibration bridging.

For rooftop applications, the enclosure is engineered to carry wind and snow loads per local structural codes, with hot-dip galvanised steel frame and Aluzinc or powder-coated panels rated for outdoor exposure. Access doors on all sides allow maintenance of all serviceable components without enclosure modification.