DA04 Air System Balancing – in HVAC

DA04 Air System Balancing – in HVAC is a new Design Application (DA) manual in AIRAH’s collection of technical resources.

This DA manual discusses the testing, adjusting and balancing (TAB) of air distribution systems in heating, ventilation, air conditioning and refrigeration (HVAC&R) applications.

The primary purpose of DA04 is to promote best practice for the balancing of air distribution systems in HVAC&R, recognising acceptable industry-standard techniques to be used in the implementation of TAB. It also highlights the importance and complexity of HVAC air balancing, which is often underestimated by many stakeholders.

Why is this topic important?

The accurate measurement and adjustment of airflow rates using a recognised and reliable process during commissioning ensures that plant and equipment are adjusted and set correctly to meet the specified design operating conditions.

A good working knowledge of the fundamentals of air-side system balancing should underpin the skills of HVAC&R system designers, installers, operators and maintainers to ensure that the TAB process is carefully considered at each stage of a construction – from concept design through to operation. 

Released in June 2021, DA04 covers:

  • Commissioning and TAB – an overview
  • Fundamentals of airflow in ducts
  • Measuring airflow
  • Preparing and programming for TAB
  • Air balancing procedures
  • Components and TAB
  • The systems approach 
  • Recording and reporting.

DA04 is designed for:

This manual has been prepared to provide both theoretical and practical knowledge to help assist those involved in the process of testing, adjusting and balancing air systems within the HVAC&R industry. This includes engineers, architects and contractors, as well as equipment owners, operators and specifiers.

DA04 release schedule

  • May 3, 2021 – Hard copy pre-order pricing begins
  • June 1, 2021 – Regular pre-order pricing begins; digital release of DA04
  • June 3, 2021 – Hard copy release (coinciding with the Commissioning Virtual Forum)


  AIRAH members  Non-members
Digital access
Hard copy
$79 $229
Hard copy package
(DA04 + DA24)
$118 $418

GST included

Access the digital version  |  Order a hard copy

For more information about downloading DA Manuals on Adobe Digital Editions, please click here.

You can also save on your hard copy order of DA04 when you bundle it with DA24 Hydronic System Balancing – in HVAC. Please click here for more information on this package.

About DA04

Air-based heating, ventilation and air conditioning systems provide comfort conditions within buildings, support many processes, and enable many systems. Owners, managers and operators rely on these often complex systems to operate their buildings and successfully run their businesses. 

HVAC systems are designed to deliver pre-calculated amounts of conditioned air down sometimes complex air distribution systems – all controlled by dynamic and responsive comfort controls. In order for them to have any chance of performing as the designer intended, these systems must be tested, adjusted and balanced (TAB) after installation, and, importantly, the air distribution quantities must be measured, adjusted and verified against the design.

To understand the best way to air-balance a system, the technician must understand how the system is intended to operate. This knowledge transfer is the responsibility of the system designer, and it is important that the designer clearly communicates the intended operation and performance of the system and how it is to be verified. This is the starting point of the TAB process.

This application manual considers the entire air-balancing story. Starting from an explanation of where TAB sits within the overall commissioning process, the manual takes us through the fundamentals of air measurement, what needs to be done before TAB, how to approach an air balance for a range of system types, and what to do after the air balance has been successfully completed, including recording and witnessing results. 

The technical details of air measurement instrumentation, what to use where and when, how things work, what works where, what not to use and, importantly, how to tie all measurements back to trusted and verified onsite performance tests are all covered.

The correct documentation of the final TAB results is highlighted as an important link to successful ongoing operation and maintenance. A typical commissioning report format and several suggested record sheets are provided in an appendix. 

The intention for this application manual is to help industry standardise the way an air balance is performed, with a strong focus on the application of best practice air balance to optimise the ongoing energy efficiency and energy consumption of the system. 

TAB is not just a verification hoop that the system has to pass – the focus is not just to “make the system work” – TAB is an essential part of the commissioning process, where an inanimate collection of objects is brought to life as a dynamic operating system and set to work as intended. The focus is the entire system as well as the individual components.

This application manual is the definitive reference for HVAC air balance in Australia. This is a document designed for, and used by, the TAB technician, but can also be used by HVAC system designers and installers to understand their roles in the process. Anyone involved in air balancing or in HVAC&R system commissioning or recommissioning should keep a copy of this manual handy.

This page was last updated July 22, 2021