By Eamonn Ryan

The following is derived from a Cape Town TechTalk on 10 June by Theo van der Linde, Pr. Tech, Head of Project at SFI Group, on the topic ‘Basics of Airflow Commissioning’. This is Part 2 of an ten-part article.

Thorough documentation and effective training are critical for the long-term success and maintainability of any HVAC system.

Thorough documentation and effective training are critical for the long-term success and maintainability of any HVAC system. Freepik

…continued from Part 1.

Thorough documentation and effective training are critical for the long-term success and maintainability of any HVAC system.

  1. Comprehensive reporting: Commissioning reports must be detailed and comprehensive. They should include:
  • Detailed procedures: A clear description of the testing procedures followed
  • Accurate results: All measured data, including airflow rates, temperatures, pressures, and control sequences
  • Rectification actions: A record of any issues identified and the corrective actions taken
  • Visual aids: Incorporating photographs and diagrams to provide a clearer understanding of the site conditions and issues. The aim is to create a report so comprehensive that anyone reading it feels as though they were present on site, experiencing the commissioning process firsthand. This minimises back-and-forth queries and ensures efficient troubleshooting in the future
  1. Operator training: Providing adequate training to building operators and maintenance personnel is crucial. This empowers them to:
  • Understand system operation: comprehend how the HVAC system functions under various conditions
  • Perform routine maintenance: conduct necessary preventative maintenance tasks effectively
  • Basic troubleshooting: identify and address minor issues, reducing reliance on external support
  • Access documentation: know where to find and how to interpret the commissioning documentation and troubleshooting procedures

 

Equipment used for airflow commissioning

Accurate measurements are fundamental to effective airflow commissioning. Various specialised tools are employed for this purpose:

  • Hot wire anemometers: these devices are used to measure air velocity at specific points, offering precise readings for duct traverses and grille measurements
  • Pressure differential sensors/manometers: essential for measuring static and differential pressures across coils, filters and fans, which are crucial indicators of airflow resistance and fan performance
  • Capture hoods (balometers): these are perhaps the most common and effective tools for measuring volumetric airflow directly at diffusers and grilles. They essentially capture the air flowing from an outlet, providing a direct cubic feet per minute (CFM) or litres per second (L/s) reading
  • Thermal anemometers: similar to hot wire anemometers but often with additional capabilities for temperature measurement
  • Pitot tubes: used in conjunction with manometers for accurate velocity measurements within ducts, especially at higher air velocities

Continued in Part 3…

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