HVAC Commissioning: Testing, Adjusting, and Balancing for Optimal Performance

Commissioning Scope and Objectives

HVAC commissioning verifies that systems meet design specifications, owner's project requirements, and applicable standards. Key objectives include achieving design airflow rates at each terminal, maintaining specified pressure relationships between spaces, ensuring adequate ventilation rates, verifying control sequences, and documenting system performance for operations and maintenance teams.

Testing and Balancing Procedures

TAB follows a systematic approach from source to terminals:

• Fan performance testing: Measure airflow, static pressure, motor power against design curves
• Ductwork traverse: Pitot tube measurements at key locations to verify airflow distribution
• Terminal device adjustment: Balance diffusers, grilles, and VAV boxes to design cfm/l/s
• Pressure relationship verification: Ensure correct positive/negative pressures between zones
• Filter resistance testing: Confirm pressure drops across filtration systems
• Control system verification: Test sensors, actuators, and control logic sequences

Critical Testing Parameters

Airflow accuracy within ±10% of design, differential pressures within specifications (e.g., operating rooms +2.5 Pa, laboratories -5 to -10 Pa), temperature control within ±1°C of setpoint, noise levels below specified NC or NR curves, energy consumption versus design predictions, and proper ventilation rates per ASHRAE 62.1 or EN 16798 standards.

Documentation and Handover

Comprehensive commissioning reports include equipment schedules with as-tested performance, airflow diagrams with measured values, control sequences as-built documentation, deficiency lists and resolution tracking, operations and maintenance training records, and trend logs demonstrating stable operation. This documentation is required for LEED, BREEAM, or other building certifications.