Strutt|Input Data|Empirical|Air Compressor (Large) inserts sound power levels into the active row of the worksheet. Sound power levels can be calculated for rotary and reciprocating compressors (including partially muffled inlets) and centrifugal compressors (casing noise excluding air inlet noise or unmuffled air inlet noise excluding casing noise)
Overall sound power levels are calculated using the following equations:
Rotary and Reciprocating Compressors
`L_W = 90 + 10log_10(kW)` (dB re 10-12 W)
Centrifugal Compressors (casing noise excluding air inlet noise)
`L_W = 79 + 10log_10(kW)` (dB re 10-12 W)
Centrifugal Compressors (unmuffled air inlet noise excluding casing noise)
`L_W = 80 + 10log_10(kW)` (dB re 10-12 W)
Octave band levels have then been derived from the overall levels by subtractive the corrections listed below:
| Compressor Type | Rotary and Reciprocating | Centrifugal (Casing) | Centrifugal (Air inlet) |
| 31.5 Hz | 11 | 10 | 18 |
| 63 Hz | 15 | 10 | 16 |
| 125 Hz | 10 | 11 | 14 |
| 250 Hz | 11 | 13 | 10 |
| 500 Hz | 13 | 13 | 8 |
| 1 kHz | 10 | 11 | 6 |
| 2 kHz | 5 | 7 | 5 |
| 4 kHz | 8 | 8 | 10 |
| 8 kHz | 15 | 12 | 16 |
References: