HVAC Procedure and Performance Guide

Adjust bypass damper

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Damper must provide specified bypass air-flow.  Applicable safety procedures must be followed.


    1. Review job specifications.
    2. Determine required bypass air-flow.
    3. Collect tools, equipment and materials.
    4. Put on safety and protective equipment and apparel.
    5. Verify that equipment is operating at rated capacity.
    6. Select velocity-measuring device and prepare opening for probe insertion.
    7. Measure air-flow in bypass duct and regulate damper to desired setting.
    8. Seal hole in duct.
    9. Leave equipment in required operating status.
    10. Remove safety and protective equipment and apparel.
    11. Gather tools, equipment and leftover materials, and leave work site clean.