Spectra Tech employes sophisticated equipment and software to automatically measure and document the Room Criteria (RC) Curve values of interior noise, primarily resulting from the building’s HVAC system operation. We can also provide assistance in designing solutions to reduce excessive noise.

  • The Room Criteria Curves were developed in cooperation with ASHRAE to form a universal standard by which HVAC noise could be quantified.
  • The test consists of recording the average unweighted (fast response) sound levels for each octave frequency band between 63 Hz and 8,000 Hz (8KHz) while the building’s mechanical systems are in their typical operating mode.
    Spectra Tech Ltd, data logging computer system, on-site field test
  • The test results are plotted over a family of reference curves, and computations are made to allow for deficiencies. The corresponding value of the plot at 1000 Hz is the RC value.
  • Plot / Print Test Results: We can provide documentation of test results by plotting / printing the test values on paper, and / or provide the reslts in PDF format.