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Regenerated Noise - Dampers    1/1

Strutt|Mechanical Services|Regenerated Noise|Damper inserts sound power levels into the active row of the worksheet.

Regenerated noise can be calculated using the Woods, SRL or CIBSE methods.


Woods
calculates regenerated noise from dampers using:


SRL calculates regenerated noise from dampers using:

The simple CIBSE method calculates the regenerated noise using:

`L_W=K_t+10log(S)+60log(V)+C+Delta L_("turb")`

where:
`K_t` is a constant depending on the duct fitting type. `K_t=-5` for a butterfly damper
`S` is the duct cross-sectional area (mē)
`V` is the duct velocity (m/s)
`C` is a spectrum correction term (from Table 5.1 CIBSE Guide B)
`DeltaL_(turb)` is a user-inputted correction (dB) increasing the sound power levels to account for turbulent inflow onto the fittings.

Note there is a more-detailed CIBSE method based on the pressure loss factor etc, the Regenerated Noise from Duct Fittings (Detailed) calculation, which can be used if the pressure drop and loss factor of the fitting are known

References:


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