Product Overview

Summary: This Airflow Measurement and Balancing Safe Operating Procedure provides a clear, repeatable method for testing, adjusting and documenting airflow in HVAC and ventilation systems. It helps Australian workplaces maintain safe indoor air quality, manage contaminants, and comply with WHS obligations for ventilation in offices, workshops, laboratories, healthcare, and industrial facilities.

Effective airflow measurement and balancing is critical to maintaining safe, healthy and compliant workplaces across Australia. Poorly balanced ventilation systems can lead to inadequate fresh air, build‑up of fumes or contaminants, thermal discomfort, pressure imbalances between rooms, and increased risk of airborne disease transmission. This Safe Operating Procedure sets out a structured, step‑by‑step process for planning, measuring, adjusting and verifying airflow performance in HVAC and ventilation systems, ensuring they operate as designed and in line with relevant Australian Standards and WHS expectations.

The document provides a practical framework that technicians, building managers and WHS professionals can rely on to achieve consistent, defensible results. It covers preparation and safety checks, selection and use of airflow measurement instruments, balancing strategies for supply and return systems, pressure relationship control (e.g. between clean and dirty areas), and clear acceptance criteria. It also embeds WHS risk controls, documentation requirements and communication steps so that airflow balancing activities are carried out safely, transparently and in a way that supports regulatory compliance, tenant comfort and long‑term asset performance.

Key Benefits

• Ensure ventilation systems deliver adequate outdoor air and contaminant control in line with Australian WHS expectations.
• Reduce health risks associated with poor indoor air quality, airborne contaminants and pressure imbalances.
• Standardise airflow testing and balancing methods across technicians and contractors for consistent, reliable results.
• Demonstrate due diligence and compliance with relevant Australian Standards, codes and building services specifications.
• Streamline commissioning, re‑commissioning and ongoing maintenance activities through clear, documented procedures.

Who is this for?

• HVAC Technicians
• Mechanical Services Contractors
• Commissioning Engineers
• Facility and Building Managers
• WHS Managers and Advisors
• Property and Asset Managers
• Maintenance Supervisors
• Laboratory Managers
• Healthcare Engineering Services Managers
• Cleanroom and Controlled Environment Coordinators

Hazards Addressed

• Exposure to airborne contaminants due to inadequate ventilation or exhaust
• Spread of airborne infectious agents through poorly balanced airflows
• Thermal stress and discomfort from uneven air distribution
• Back‑drafting of combustion appliances caused by incorrect pressure relationships
• Ingress of dust, fumes or odours into clean or sensitive areas
• Slips, trips and falls while accessing ceiling spaces, plant rooms and ductwork
• Electrical hazards when working near HVAC plant and control systems
• Manual handling injuries from moving ladders, access panels and test equipment

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Terminology (Airflow, Pressure, ACH, Diversity, etc.)
• 3.0 Roles and Responsibilities (Technicians, Supervisors, WHS Representatives)
• 4.0 Applicable Legislation, Standards and Reference Documents
• 5.0 Hazard Identification and WHS Risk Controls for Airflow Balancing Activities
• 6.0 Required Tools, Test Instruments and Personal Protective Equipment (PPE)
• 7.0 Pre‑Start Checks and System Readiness Verification
• 8.0 Access, Isolation and Lockout Requirements for HVAC Plant
• 9.0 Airflow Measurement Methods (Grilles, Diffusers, Ducts, Hoods and Pitot Tubes)
• 10.0 Balancing Strategy and Sequencing (Supply, Return, Exhaust and Relief Air)
• 11.0 Pressure Relationship Testing Between Rooms and Zones
• 12.0 Acceptance Criteria, Tolerances and Deviation Management
• 13.0 Documentation, Test Reports and Record‑Keeping Requirements
• 14.0 Communication and Handover to Clients, Tenants and WHS Representatives
• 15.0 Troubleshooting Common Airflow and Balancing Issues
• 16.0 Training, Competency and Authorisation Requirements
• 17.0 Review, Continuous Improvement and Re‑commissioning Triggers

Legislation & References

• Work Health and Safety Act 2011 (Cth) and equivalent state and territory WHS legislation
• Work Health and Safety Regulations 2011 (Cth) and equivalent state and territory WHS regulations – provisions relating to ventilation and airborne contaminants
• Safe Work Australia – Managing the Work Environment and Facilities: Code of Practice
• Safe Work Australia – Managing the Risk of Airborne Contaminants at the Workplace: Code of Practice
• AS 1668.2: The use of ventilation and air conditioning in buildings – Mechanical ventilation in buildings
• AS 1668.1: The use of ventilation and air conditioning in buildings – Fire and smoke control in buildings
• AS/NZS 3666.1: Air-handling and water systems of buildings – Microbial control – Design, installation and commissioning
• NCC (National Construction Code) – Performance requirements for ventilation and indoor environment