Characterisation of acoustic louvres panel for Heating Ventilating and Air Conditioning (HVAC) noise control

Abstract

This paper presents the results of research about louvre panels with 4 blades, 5 blades, and 6 blades for mechanical and acoustical performance which installed at the outlet of the ducting system. The mechanical performance will show up the airflow velocity and pressure drop, for the acoustical performance will analysed for its ability to reduce noise in the HVAC System. The measurement method used a rectangular linear duct with the inlet of a fan as an airflow source and loudspeaker as a noise source. The ability tested from the acoustic parameters of TL and the directivity of the noise from the outlet section, as well as mechanical analysis performance based on airflow and pressure drop. For the pressure drop parameter value is up to 20 Pa for 4 blades louvre, and about 24 Pa for 5 blades and 6 blades louvre. By using third octave band filter from 20 to 8000 Hz, the highest TL value is at 27 dB at a frequency of 63 Hz. For the directivity used to determine the distribution of sound energy around the outlet, it shows that the highest SPL value is at a frequency of 1 kHz with the difference from the perpendicular angle of the outlet after being given a louvre acoustic panel of 12 dB. So, the installation of louvre panels has small of pressure drop effect, but it can be effective for noise reduction.