Strutt|Mechanical Services|Regenerated Noise|Attenuator (FanTech) inserts sound power levels into the active row of the worksheet.
The calculation is based on the free area and the module width of the rectangular attenuator (determined from the model number), as well as the flow rate, width and height of the attenuator.
The formula for calculating the FanTech attenuator regenerated noise has been provided by the manufacturer.