NASCLA Accredited Commercial General ContractorFinishesEasy
A commercial contractor is installing a new suspended acoustical ceiling in a large open-plan office. The specifications require the ceiling system to effectively block sound transmission between adjacent workspaces. Which critical performance rating should the contractor prioritize when selecting the acoustical panels?
- ALight Reflectance Value (LRV)
- BCeiling Attenuation Class (CAC)
- CFire Resistance Rating (FRR)
- DNoise Reduction Coefficient (NRC)
Show answer & explanationAnswer & explanation
Correct answer: B. Ceiling Attenuation Class (CAC)
Ceiling Attenuation Class (CAC) measures the ceiling's ability to block sound transmission between adjacent spaces, which is crucial for privacy in open-plan offices. NRC measures sound absorption within a space, LRV is for light reflection, and FRR is for fire safety.
Why the other options are wrong
- A. LRV measures the percentage of light reflected by a surface, which is unrelated to sound blocking.
- C. FRR relates to the ceiling's ability to resist fire, not its acoustic performance.
- D. NRC measures sound absorption within a room, not sound blocking between rooms.
Ceiling Attenuation Class (CAC)
A single-number rating that quantifies a ceiling system's ability to block sound transmission between adjacent closed spaces through a shared plenum.
- Higher CAC values indicate better sound blocking performance.
- Crucial for privacy in offices and healthcare settings.
- Measured by ASTM E1414 standard.
Memory trick: Sound blocking needs CAC, absorption needs NRC.