8 www. refrigerationandaircon. co. za RACA Journal I July 2026
TECH TALK networking
Commissioning typically takes one of two forms. Initial commissioning is carried out on new installations or systems that have been recently completed, verifying that they meet design requirements from the outset. Re-commissioning, on the other hand, applies to existing systems and is often undertaken to validate or improve performance, or to provide updated documentation. In certain facilities, such as biosafety laboratories or pharmaceutical environments, this process becomes a recurring requirement. Annual validation, including airflow verification and particle counting, is often mandated to ensure continued compliance with regulatory standards.
Airflow commissioning touches nearly every component within an HVAC system. From air handling units and fans to diffusers, ductwork and fan coil units, each element plays a role in the movement and conditioning of air. Even systems not typically associated with airflow, such as chillers or refrigeration units, depend on adequate air movement for effective heat exchange. Without airflow, there is no meaningful transfer of energy, and without that, the system simply cannot perform its intended function.
THE COMMISSIONING PROCESS: PREPARATION, TESTING AND BALANCING The success of commissioning depends heavily on preparation: before arriving on site, it is essential to understand the system being commissioned, the design requirements and the potential failure points. Many of the challenges encountered during commissioning are not the result of complex faults, but rather of inadequate preparation. A technician who arrives on site without a clear plan may spend hours tracing issues that could have been identified in minutes through careful review of drawings and specifications.
The commissioning process itself follows a logical sequence. It begins with planning and design review, ensuring that the intended performance criteria are clearly understood. This is followed by inspection of the installation, where equipment, ductwork and controls are checked against design drawings and manufacturer specifications. Only once the system has been verified as correctly installed should functional testing begin. This involves operating the system under various conditions – cooling, heating and ventilation – and confirming that it responds appropriately to control inputs and safety requirements.
Air balancing forms a critical part of this process. It is not sufficient for a system to deliver airflow; it must deliver the correct airflow. Over-delivery can be just as problematic as under-delivery, leading to increased energy consumption, higher thermal loads and unnecessary strain on equipment. Achieving the correct balance requires careful adjustment of dampers, valves and fan speeds, ensuring that each part of the system performs in harmony with the whole.
8 www. refrigerationandaircon. co. za RACA Journal I July 2026