HVAC Procedure and Performance Guide

TASK: Modify existing duct for duct-mounted accessories installation (air cleaner or damper)

Training for this procedure can be found in these courses:

                         103 – Basic Sheet Metal  and  205 – HVACR High Efficiency Ventilation


Duct must be modified to accommodate specified accessory according to manufacturer’s specifications and job specifications.  Applicable safety procedures must be followed.


  1. Review manufacturer’s specifications and job specifications.
  2. Collect tools, equipment and materials.
  3. Put on safety and protective equipment and apparel.
  4. Determine location, dimensions and mounting requirements for element housing.
  5. Ensure that duct size is correct.
  6. Prepare transitions to connect element housing to duct.
  7. Remove insulation.
  8. Remove duct section and install inlet and outlet transitions with correct space and housing installation.
  9. Replace duct insulation and insulate transitions.
  10. Remove safety and protective equipment and apparel.
  11. Gather tools, equipment and leftover materials and leave work site clean.