Articles tagged “NC curve”

Noise Criteria Explained: NR, NC, and RC Curves — Which One Does Your Project Need?

NR (Noise Rating), NC (Noise Criteria), and RC (Room Criteria) all rate background noise levels in buildings — but they use different curves, different frequency ranges, and are required by different standards. Here is how each system works, when to use which, and the specific values your HVAC engineer needs to hit.