Where does the noise come from?
From the units themselves, from air velocity at outlets, from ducts carrying plant or adjacent-room noise, and from plant vibration transmitted through the structure.
Quietness criteria
NC or NR curves set the target: about NC 15–20 for concert halls, NC 20–25 for theatres and around NC 25–30 for lecture and conference halls.
Solutions
Low air velocities and larger outlets, duct attenuators, lined ducts, plant on resilient bases, and units located away from the hall.
Coordination
Coordination between the acoustic designer and the HVAC engineer at design stage prevents most problems.
Key takeaways
- HVAC is a major noise source in the Gulf.
- Set an NC target.
- Coordinate early with the HVAC engineer.
This article is for general education; final design decisions are based on each project’s study and the competent authorities’ requirements.