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dBA, NR, NC & PNC#

The single figure index for rain noise calculations can be changed from the Settings window.

When the Settings > Calculation > Roof menu is open, the single figure index for the predictions can be set. The following options are available (definitions are included below):

  • dBA
  • NR
  • NC
  • PNC

SettingsRoofTab.png

dBA#

A-weighted Decibel. The A-weighting approximates the response of the human ear.

NR#

Noise Rating. A single number rating which is based on the sound level in the octave bands 31.5Hz - 8kHz inclusive, generally used to assess noise from mechanical services in buildings.

NC#

Noise Criteria. A single number rating which is based on the sound level in the octave bands 31.5Hz - 8kHz inclusive, generally used to assess noise from mechanical services.

PNC#

Preferred Noise Criteira. A single number rating which is based on the sound level in the octave bands 31.5Hz - 8kHz inclusive, generally used to assess noise from mechanical services.