Optimizing Ceiling Systems and Lightweight Plenum Barriers to Achieve Ceiling Attenuation Class (CAC) Ratings of 40, 45 and 50

Authors

  • Gary S. Madaras ROCKFON
  • Andrew E. Heuer NGC Testing Services

Abstract

Acoustics is one of the lowest scoring indoor environmental quality metrics in building occupant surveys.  This is in part due to the misconception that a modular acoustic ceiling alone can be used to block noise when a room's demising walls do not extend full height.  Acoustic codes, standards and guidelines typically require 40, 45 or 50 decibels (dB) of isolation between rooms, yet most ceiling panels only provide 20-35 dB of inter-room blocking.  Penetrations for lights, grilles and diffusers, can decrease Ceiling Attenuation Class (CAC) by 10 points overall and 20 dB in the 1,000, 2,000 and 4,000 Hertz (Hz) octave bands.

 

A full-height wall is the preferred way to block inter-room noise transfer, but when combined with the 20-25 dB of blocking provided by typical ceiling systems that have been penetrated by lighting and air distribution devices, it can result in unnecessary costs to the project.  The isolation provided by the ceiling and upper wall exceeds that provided by the lower wall.  Laboratory tests were conducted to optimize combinations of modular acoustic ceilings and lightweight, top-of-wall, plenum barriers that result in CAC ratings of 40, 45 and 50 points.  The ceiling systems and plenum barriers contained multiple penetrations for building services, representing real-world applications.

 

This research is a continuation of the research presented at Acoustics Week in Canada 2015 in Halifax.

Author Biographies

Gary S. Madaras, ROCKFON

Dr. Madaras is the Acoustics Specialist for ROCKFON in North America.

Andrew E. Heuer, NGC Testing Services

Mr. Heuer is a Senior Test Engineer at NGC Testing Services.

Additional Files

Published

2016-08-24

How to Cite

1.
Madaras GS, Heuer AE. Optimizing Ceiling Systems and Lightweight Plenum Barriers to Achieve Ceiling Attenuation Class (CAC) Ratings of 40, 45 and 50. Canadian Acoustics [Internet]. 2016 Aug. 24 [cited 2024 Nov. 23];44(3). Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/2914

Issue

Vol. 44 No. 3 (2016)

Section

Proceedings of the Acoustics Week in Canada

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