HVAC Procedure and Performance Guide
Adjust fan speed for correct CFM output
STANDARD OF PERFORMANCE
Fan must deliver specified CFM air-flow. Speed must be adjusted by reconnecting multi-speed motor, adjusting variable belt sheaves, or changing belt sheaves. Applicable safety procedures must be followed.
- Review manufacturer’s specifications and job specifications.
- Determine required air-flow and available adjustment options.
- Collect tools, equipment and materials.
- Put on safety and protective equipment and apparel.
- Measure air-flow and compare duct air-flow measurements to specifications. (Note: Ensure that duct is not blocked by closed dampers or other obstructions and that filters are clean).
- Remove safety guard(s) and access cover(s).
- Adjust fan speed to obtain desired flow.
- Reconnect multi-speed motor to higher or lower speed as required.
- Adjust variable belt sheaves for higher or lower fan speed as required, and reset belt tension.
- Change belt sheaves and belt if necessary.
- Re-measure air-flow and verify that air-flow is within specifications.
- Check motor amperage and verify that motor is not overloaded. (Note: If overload condition exists, install larger motor).
- Replace safety guard(s) and access cover(s).
- Leave equipment in required operating status.
- Remove safety and protective equipment and apparel.
- Gather tools, equipment and leftover materials, and leave work site clean.