Noise Criteria Curves: NC
NC-55#63 to NC-60#8000
Noise Criteria (NC) and Room Criteria (RC) curves for HVAC acoustics design. NC curves per ANSI S12.2-2008 from NC-15 through NC-70 (12 curves), and RC Mark II curves per ASHRAE from RC-25 through RC-50 (6 curves). Each curve has 8 octave band center frequencies (63-8000 Hz) with maximum allowable sound pressure levels in dB. Includes recommended occupancy type and equivalent dBA background noise level. 144 records total.
| criterion type | curve point | background noise dBA equivalent (dBA) | max sound pressure level dB (dB) | octave band center Hz (Hz) | rating | recommended occupancy |
|---|---|---|---|---|---|---|
| NC | NC-55#63 | 65 | 74 | 63 | NC-55 | factory |
| NC | NC-55#8000 | 65 | 52 | 8,000 | NC-55 | factory |
| NC | NC-60#1000 | 70 | 61 | 1,000 | NC-60 | factory |
| NC | NC-60#125 | 70 | 71 | 125 | NC-60 | factory |
| NC | NC-60#2000 | 70 | 59 | 2,000 | NC-60 | factory |
| NC | NC-60#250 | 70 | 67 | 250 | NC-60 | factory |
| NC | NC-60#4000 | 70 | 58 | 4,000 | NC-60 | factory |
| NC | NC-60#500 | 70 | 63 | 500 | NC-60 | factory |
| NC | NC-60#63 | 70 | 77 | 63 | NC-60 | factory |
| NC | NC-60#8000 | 70 | 57 | 8,000 | NC-60 | factory |
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