HVAC Procedure and Performance Guide

TASK Install factory-fabricated filter box on air-handling unit (new installation).

Training for this procedure can be found in these courses:

                         123 – Air Distribution  and  205 – HVACR High Efficiency Ventilation


Filter box must be installed according to manufacturer’s specifications and job specifications.  Filter box must not leak.  Return air and makeup air must pass through filters without excessive pressure loss.  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. Ensure that filter box is correct size and type for application.
  5. Install gaskets and secure filter box to air-handling unit according to manufacturer’s specifications.
  6. Connect return duct to return connection using flexible connectors.
  7. Connect fresh air intake duct to filter box.
  8. Install filters.
  9. Start unit if job progress permits and check operation:
    •  Adjust air intake for desired fresh airflow.
    • Measure pressure drop across filters.
    • Adjust fan or system dampers.
  10. Insulate box and duct.
  11. Remove safety and protective equipment and apparel.
  12. Gather tools, equipment and leftover materials and leave work site clean.