HVAC Procedure and Performance Guide

TASK: Install humidifier: self-contained through wall or ducted

Training for this procedure can be found in these courses:

                         205 – High Efficiency Ventilation   and   241 – Intro to Cooling Systems


Humidifier must be installed according to manufacturer’s specifications and job specifications.  Unit must operate quietly and respond to control signal; it must not leak or overflow.  Applicable safety procedures must be followed.


  1. Review job order, manufacturer’s specifications and job specifications.
  2. Collect tools, equipment and materials.
  3. Put on safety and protective equipment and apparel.
  4. Determine type of installation.
    1. Mounted through wall with distribution registers on unit, or
    2. Situated in separate location and ducted to register mounted in wall.
  5. Prepare applicable wall openings.
  6. Install equipment in wall or separate location according to manufacturer’s specifications.
  7. Install wall register and manufacturer-recommended duct to humidifier, if applicable.
  8. Make electrical connections.
  9. Connect low-voltage wires from humidistat.
  10. Connect water supply to water inlet.
  11. Install overflow and drain.
  12. Inspect installation. 
  13. Start unit and check operation.
    1. Adjust water level or flow control.
    2. Ensure response to humidistat’s signal.
    3. Ensure correct operation according to manufacturer’s specifications.
  14. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
  15. Make final inspection of work.
  16. Leave equipment in required operating status.
  17. Remove safety and protective equipment and apparel.
  18. Gather tools, equipment and leftover materials, and leave work site clean.