ASHRAE’s 2019 edition of Standard 62.1 marked a pivotal step for the Indoor Air Quality Procedure (IAQP). However, it was the subsequent series of addenda that began transforming it from a conceptual alternative into a structured, data-driven design pathway. These interim updates introduced key clarifications, standardized documentation, and early guidance that laid the groundwork for broader industry adoption.
The momentum continued with the fully revised ASHRAE Standard 62.1-2022, which formalized many of these advancements by introducing official verification testing, a standardized IAQP Calculator, and defined performance validation requirements. Together, these updates strengthened IAQP’s credibility and usability across design teams.
Now, as ASHRAE continues to refine IAQP through new post-2022 addenda, this article reviews the most recent changes, how they build on the 2022 foundation, further align the procedure with third-party testing and data transparency, and continue to move IAQP toward confident, standardized application.
IAQP Addenda Summary (2022-Present)
Key updates driving IAQP’s maturation and ease of use:
- Addendum c (2024 0521): Addendum 62c strengthens the IAQP by introducing a calculator for mass balance equations and updating reference materials, making IAQ calculations more accurate, consistent, and easier to apply in practice.
- Addendum f (2025 0930): Addendum 62f strengthens the IAQP by requiring control system modes for air quality emergencies, such as economizer and demand control ventilation shutdowns and infection risk management, ensuring buildings can rapidly adapt to contaminated or high-risk conditions while maintaining safe indoor air quality and operational reliability.
- Addendum g (2024 1031): Addendum 62g enhances the IAQP by adding standardized documentation templates for air cleaning systems, improving consistency, transparency, and ease of demonstrating compliance with Section 6.3 requirements.
- Addendum i (2024 1031): Addendum 62i advances the IAQP by introducing alternative, globally recognized testing methods for formaldehyde, acetaldehyde, and acetone, reducing costs and expanding laboratory accessibility while maintaining rigorous accuracy making IAQP implementation more practical, affordable, and broadly adoptable.
- Addendum n (2022 0930): Addendum 62n reinforces the IAQP’s scientific credibility by mandating that filtration and air cleaning devices be tested to recognized ASHRAE or ISO standards, ensuring verified performance data, greater design reliability, and stronger assurance that IAQP-based ventilation solutions deliver the intended indoor air quality.
- Addendum o (2024 0501): Addendum 62o enhances the IAQP by expanding documentation requirements to include design standard edition, filter and air cleaner ratings, and last air balancing date, improving operational transparency and helping ensure ongoing alignment between design intent and actual IAQ performance.
- Addendum q (2024 1031): Addendum 62q updates IAQP Table 6.5 by removing the obsolete compound 1,1,1-trichloroethane and revising phenol limits per AgBB 2018, ensuring the procedure remains current, evidence-based, and aligned with modern health standards.
- Addendum r (2025 0430): Through Addendum 62r, the IAQP aligns with the updated EPA PM2.5 standard of 9 µg/m³, enhancing health protection and demonstrating the procedure’s commitment to staying scientifically current and responsive to evolving air quality research.
- Addendum s (2025 0430): The IAQP broadens its testing flexibility by adding EPA Method TO17 and updating TO11 to TO11A, expanding laboratory options, improving analytical accuracy, and lowering testing costs, making IAQ assessments more accessible and reliable.
- Addendum v (2025 0930): Addendum 62v updates IAQP references and Table 6.5 limits to reflect current industry standards and authorities, ensuring designs stay accurate and consistent with modern best practices.
What This Means for the Industry
Collectively, these addenda mark more than technical refinement, they mark a defining moment for performance-based ventilation. The IAQP has evolved from a theoretical compliance path into a practical, scalable, and verifiable design framework. One that allows engineers to achieve measurable indoor air quality while reducing energy and capital costs. With the release of standardized tools, validated testing methods, and third-party verification requirements, the IAQP has entered a new phase: accelerated adoption.
Across the HVAC and building design industry, engineering firms, manufacturers, and building owners are beginning to embrace IAQP not as an exception, but as the preferred pathway for meeting both IAQ and energy goals. This adoption reflects a fundamental shift away from prescriptive ventilation rates and toward performance-based accountability. IAQP bridges the gap between indoor environmental quality, sustainability, and cost efficiency.
At AirBox, we see these advancements as a validation of what we’ve built our mission around: that clean, healthy air should be scientifically verified, performance-based, and achievable at scale. The latest addenda have provided the market with the structure it needed to transition from concept to confidence, and the industry is responding. IAQP is no longer emerging; it’s establishing the new baseline for how buildings will be designed, validated, and maintained for decades to come.
