CIBSE's Commissioning Code A covers setting air systems to work, functional tests and regulation. Measurements need a known comparator. If design evidence is missing, establish the appropriate assessment before adopting current settings as targets.
Check readiness before adjustment
Confirm system condition, controls and operating state before measurement. Rectify relevant filter blockages, duct damage and equipment faults; adjustment elsewhere should not conceal a defect that prevents meaningful results.
Provide safe access to plant and measurement points. Agree operating conditions during the work and record them with readings, allowing for fan-speed, demand or room-use changes that affect comparisons.
Understand what balancing can and cannot resolve
Balancing can correct distribution departing from the intended design. It cannot supply capacity beyond the plant or ducts, or repair defective parts. Investigate room-temperature complaints across airflow, controls and heat gains as appropriate.
Separate those causes before adjustment. Increased flow on one branch can affect others, so consider the connected system rather than treating one uncomfortable room independently.
Use the results after the visit
Require system identity, design figures, measured values, final settings and departures still unresolved. Identify terminals and locations so a subsequent engineer can trace where each result was obtained.
Record why a target was not met and the required next step, such as repair, design assessment or separately scoped work. Retain results with commissioning and maintenance evidence as the baseline for later changes.
Review after system changes
Review relevant readings after replacement, duct changes or control alterations affecting distribution. Define the affected part of the system; neither old settings nor a repeated full exercise should be accepted without considering scope.
FAQs
Does balancing mean cleaning the ducts?
No. Cleaning removes the specified contamination; balancing measures and adjusts distribution. Both may be needed, but remain separate instructions.
Can balancing fix every uncomfortable room?
No. Establish whether distribution is responsible. Plant capacity, controls, occupancy and other room conditions may require different action.
What should we provide before the work?
Provide drawings, target flows, commissioning evidence, operating information and affected areas. Flag missing records and recent changes before defining the measurement scope.
Related help
Explore Air and Ventilation Balancing, Ventilation and Air-Handling Units. Read what an air-handling unit does, or discuss system performance with design information and the affected spaces.
Review all services, maintenance, projects, sectors, locations and the knowledge centre when planning related work.
