The Silent Battle for Clean Air: Ventilation Woes in Today's Buildings

Darren Harris
February 8, 2024

In the pursuit of thermal comfort, the overlooked aspect of ventilation poses significant challenges in today's buildings. Shockingly, only about 1% of schools comply with AS 1668.2 standards for ventilation, relying instead on inadequate natural ventilation. This article highlights the critical issues surrounding ventilation in schools and commercial projects, emphasising the importance of building air-tightness testing and the installation of appropriate mechanical ventilation systems.

The Natural Ventilation Predicament

Natural ventilation, perceived as a cost-effective solution, proves unresponsive to load requirements, leading to poor air circulation. Smaller commercial projects often resort to domestic-grade reverse cycle splits, but occupants unknowingly compromise their effectiveness by closing windows, negating any fresh air supply.

State Programs and Loopholes

Well-intentioned programs, such as Queensland and NSW's 'cooler schools,' inadvertently dilute ventilation standards, perpetuating subpar systems. An NCC loophole allowing the combination of natural ventilation and split DX systems lacks compliance with air quality standards, further exacerbating the issue.

The Evolution of Building Practices

Technological advancements shifted building practices, prioritising energy efficiency but inadvertently sacrificing fresh air supply. This leaves HVAC designers in ethical dilemmas as they navigate client demands for cost savings while ensuring occupants' health.

Misconceptions and Challenges

Occupants often mistakenly believe that AC units provide sufficient ventilation, leading to a reluctance to open windows. The construction industry's focus on cost savings sometimes results in windows without flyscreens or outside locations that can quickly degrade, discouraging window use and further compromising indoor air quality.

The Importance of Building Air Tightness Testing

Building air tightness testing emerges as a crucial tool in identifying and rectifying issues in a building's envelope. It ensures that the structure is sealed effectively, minimising unwanted air infiltration and optimising the performance of ventilation systems.

Correct Mechanical Ventilation: A Vital Component

To address the challenges of poor ventilation, correct mechanical ventilation is paramount. This involves the installation of systems compliant with standards like AS 1668.2, ensuring adequate fresh air supply while maintaining energy efficiency. Building air tightness testing complements mechanical ventilation, ensuring that systems operate optimally.

The Path Forward

As we look to the future, prioritising both thermal comfort and air quality requires a holistic approach. Building air tightness testing, coupled with the correct mechanical ventilation, must become integral to construction practices. It's time to shift our focus from merely meeting minimum compliance standards to creating environments that promote health and well-being.


In the silent battle for clean air, acknowledging the impact of indoor air quality on human health is paramount. By incorporating building air tightness testing and installing appropriate mechanical ventilation, we can create buildings that not only provide efficient thermal comfort but also prioritise the health and well-being of their occupants. Remembering the mantra of "Ventilate Right, Build it Tight, check it on site," we can pave the way for a future where every breath is a breath of fresh air.

Get in contact with us today.
Darren Harris
Air Tightness Specialist