Spotlight on: AS 1668.2:2024, The use of ventilation and airconditioning in buildings – part 2: mechanical ventilation in buildings

AS 1668.2:2024, The use of ventilation and airconditioning in buildings – part 2: mechanical ventilation in buildings, has recently been released, offering essential updates to one of Australia’s most widely applied standards in the HVAC industry.  
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This latest version provides comprehensive guidelines for the mechanical ventilation of buildings, supporting practitioners in designing, installing, and maintaining ventilation systems that improve indoor air quality, safety, and compliance.
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Why the update to AS 1668.2:2024 matters

The AS 1668 series is foundational to Australian HVAC practices, helping indoor spaces maintain healthy air quality by setting minimum ventilation standards. The updates to AS 1668.2:2024 replace the 2012 edition with revised technical requirements that reflect advancements in technology and modern air quality practices.  
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For HVAC professionals, the new standard seeks to provide clearer, quantified guidelines and promote better air quality and energy efficiency across various building types.
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Key updates in AS 1668.2:2024

The revised AS 1668.2:2024 incorporates several changes that aim to streamline compliance and improve alignment with modern ventilation practices. Key updates include:
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• Quantified performance requirements: Previous editions included non-quantified performance requirements, allowing some flexibility in interpretation. The 2024 update replaces these with precise, prescriptive requirements, helping to establish a measurable standard and enhance consistency across the industry.

• Enhanced calculations for outdoor airflow and borrowed ventilation: The standard now offers both simple and detailed calculation methods for determining minimum outdoor airflow rates, allowing flexibility based on building type and complexity. Additionally, AS 1668.2:2024 introduces the concept of “borrowed ventilation” for certain spaces, enabling airflow from adjacent rooms under specific conditions to improve ventilation efficiency.

• Updated ventilation requirements for carparks: To accommodate advancements in vehicle technology and emission control, the updated standard revises contaminant generation rates for carparks. By reflecting the use of low-emission fuels and modern engine technology, the new guidelines allow for reduced ventilation rates in carparks, potentially lowering costs and energy use in building projects.

• Revised provisions for kitchen and healthcare ventilation: New provisions address kitchen exhaust and healthcare facility ventilation, aligning with contemporary practices. Notably, the standard now includes a compliance pathway for treated kitchen exhaust, offering greater design flexibility in cases where traditional vertical discharge may not be feasible.
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Benefits of AS 1668.2:2024 for industry and building occupants

AS 1668.2:2024 aims to deliver a range of advantages, from improved air quality to operational efficiencies. Target benefits include:
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• Improved indoor air quality: Updated contaminant management and airflow calculations look to support healthier environments in buildings, particularly in high-occupancy areas and specialised facilities.

• Simplified compliance: The introduction of quantified, prescriptive requirements aims to make it easier for HVAC practitioners to align with National Construction Code standards, reducing ambiguity and ensuring consistent application.

• Operational efficiency: With features like borrowed ventilation and updated carpark requirements, the standard looks to enable more efficient use of ventilation resources, translating into potential cost and energy savings.

• Cost savings: Reduced ventilation requirements for carparks and flexible options for kitchen exhaust systems can help lower installation and maintenance costs, particularly in new building projects.
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Who should use AS 1668.2:2024?

AS 1668.2:2024 could be suitable for a range of professionals and facilities across the construction and HVAC sectors:

• HVAC designers and installers: AS 1668.2:2024 aims to provide clear guidelines to support current standards for mechanical ventilation systems.

• Building managers and facility operators: Adequate ventilation is vital for indoor air quality, safety, and regulatory compliance, which can make this standard valuable for anyone managing building systems.

• Commercial kitchens and healthcare facilities: Facilities that require specialized ventilation, such as commercial kitchens and healthcare centres, could benefit from the tailored provisions in the updated standard.

• Compliance and safety teams: AS 1668.2:2024 offers a framework for enhancing ventilation safety, which can help equip safety officers and compliance teams with best practices that align with industry standards and anticipate future regulatory needs.
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Explore the standard

AS 1668.2:2024 is now available via the Standards Australia Store and our distribution partners.

• Purchase AS 1668.2:2024 – Get the latest requirements to support support current standards for mechanical ventilation systems.

• Subscribe to the HVAC Practitioners Set – Access the full suite of standards relevant to HVAC professionals, including 1668.2:2024.

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This article was originally published in November 2024.